Pressure controls and thermostats
Contents
Page
Pressure controls, type KP Introduction ................................................................................................................................ 5 Features ..................................................................................................................................... 5 Approvals ................................................................................................................................... 5 Materials in contact with the medium ........................................................................................ 5 Technical data ........................................................................................................................... 6 Ordering ..................................................................................................................................... 7 Design/Function ........................................................................................................................ 9 Terminology ............................................................................................................................. 11 Setting ...................................................................................................................................... 11 Dimensions and weights ......................................................................................................... 12
Pressure controls, differential pressure controls, type RT Introduction .............................................................................................................................. 13 Features ................................................................................................................................... 13 Technical data ......................................................................................................................... 13 Approvals ................................................................................................................................. 13 Materials in contact with the medium ...................................................................................... 14 Ordering ................................................................................................................................... 14 Design/Function - Pressure control, type RT .......................................................................... 17 Design/Function - Pressure control with dead zone, type RT L ............................................. 18 Design/Function - Differential pressure control, type RT ........................................................ 19 Terminology ............................................................................................................................. 20 Setting ...................................................................................................................................... 20 Dimensions and weight ........................................................................................................... 21
Differential pressure controls, type MP 54, 55 and 55A Introduction .............................................................................................................................. 23 Features ................................................................................................................................... 23 Approvals ................................................................................................................................. 23 Materials in contact with the medium ...................................................................................... 23 Technical data ......................................................................................................................... 24 Ordering ................................................................................................................................... 24 Design ..................................................................................................................................... 25 Terminology ............................................................................................................................. 25 Function ................................................................................................................................... 25 Dimensions and weight ........................................................................................................... 27
Cartridge pressure control, type CC 20W Introduction .............................................................................................................................. 29 Features ................................................................................................................................... 29 Function ................................................................................................................................... 29 Technical data ......................................................................................................................... 29 Dimensions and weights ......................................................................................................... 30
Danfoss A/S (RC-CM/hbs), 04 - 2002
RK0YF102
1
Pressure controls and thermostats
Contents
Page
Cartridge pressure controls, type CC 25W Introduction .............................................................................................................................. 31 Features ................................................................................................................................... 31 Function ................................................................................................................................... 31 Ordering ................................................................................................................................... 31 Technical data ......................................................................................................................... 31 Dimensions and weights ......................................................................................................... 32
Cartridge pressure controls, type CC 29B Introduction .............................................................................................................................. 33 Features ................................................................................................................................... 33 Function ................................................................................................................................... 33 Ordering ................................................................................................................................... 33 Technical data ......................................................................................................................... 33 Dimensions and weights ......................................................................................................... 34
Cartridge pressure controls, type CC 80W Introduction .............................................................................................................................. 35 Application ............................................................................................................................... 35 Features ................................................................................................................................... 35 Function ................................................................................................................................... 35 Ordering ................................................................................................................................... 35 Technical data ......................................................................................................................... 35 Dimensions and weights ......................................................................................................... 36
Thermostats, type KP Introduction .............................................................................................................................. 37 Features ................................................................................................................................... 37 Approvals ................................................................................................................................. 37 Regulating range ..................................................................................................................... 38 Technical data ......................................................................................................................... 38 Contact systems ...................................................................................................................... 39 Ordering ................................................................................................................................... 39 Design/Function ...................................................................................................................... 41 Terminology ............................................................................................................................. 42 Setting ...................................................................................................................................... 43 Charges ................................................................................................................................... 43 Dimensions and weights ......................................................................................................... 44
2
RK0YF102
Danfoss A/S (RC-CM/hbs), 04 - 2002
Pressure controls and thermostats
Contents
Page
Thermostats, differential thermostats, type RT Introduction .............................................................................................................................. 45 Features ................................................................................................................................... 45 Technical data ......................................................................................................................... 45 Approvals ................................................................................................................................. 46 Overview .................................................................................................................................. 46 Ordering ................................................................................................................................... 47 Design/Function - Thermostat, type RT ................................................................................... 49 Design/Function - Thermostats with neutral zone, type RT L ................................................. 50 Terminology ............................................................................................................................. 50 Charges ................................................................................................................................... 51 Design/Function - RT differential thermostat ........................................................................... 53 Terminology ............................................................................................................................. 53 Setting of differential ................................................................................................................ 54 Nomograms for obtained differentials ..................................................................................... 54 Dimensions and weight ........................................................................................................... 55
Universal thermostat, type UT Introduction .............................................................................................................................. 57 Approvals ................................................................................................................................. 57 Technical data ......................................................................................................................... 57 Code numbers ......................................................................................................................... 58 Dimensions and weight ........................................................................................................... 58
Danfoss A/S (RC-CM/hbs), 04 - 2002
RK0YF102
3
Pressure controls Type KP KP pressure controls are for use in refrigeration and air conditioning systems to give protection against excessively low suction pressure or excessively high discharge pressure. KP pressure controls are also used for starting and stopping refrigeration compressors and fans on air-cooled condensers. KP pressure controls are fitted with a single-pole double-throw (SPDT) switch. The position of the switch is determined by the pressure control setting and the pressure at the connector. KP pressure controls are available in IP 30 and IP 44 enclosures.
Introduction
Features
• Ultra-short bounce times Reduces wear to a minimum and increases reliability.
• KP 7 and 17 with fail-safe bellows element
• Manual control Electrical contact function can be tested without the use of tools.
• Compact design
• KP 2 with low differential for low-pressure regulation
• High reliability both electronically and mechanically.
• Vibration and shock resistant
• Fully welded bellows element
• KP 6 for HP refrigerants (R 410A, CO2) Approvals
CE-marked in accordance with EN 60947-4/-5 for sale in Europe. KP 7 and KP 17: CE marked in accordance with PED 97/23/23/EC, category IV, safety equipment
DnV, Det norske Veritas, Norway C
S UL approval for USA and Canada
RINA, Registro Italiano Navale, Italy
F Germanischer Lloyd, Germany
Materials in contact with the medium
Danfoss A/S, 05 - 2002
BV, France
D DIN 32733, Germany (KP1, KP2, KP7, KP17)
LR, England
P Polski Rejestr Statków, Poland
MRS, Maritime Register of Shipping, Russia
Unit type
Material
KP 1, 2, 5, 6, 7, 15 and 17
Tinbronze, no. 2.1020 to DIN 17662 Free cutting steel, no. 1.0737 / 1.0718 to DIN 1651
KP 1A, 5A, 6, 7A and 15A only
Stainless steel 18/8, no. 1.0737 / 1.0718 to DIN 17440 Free cutting steel, no. 1.0719 to DIN 1651 Steel, no. 1.0330 to DIN 1624 Aluminium, no. 3.0255 to DIN 1712
Technical leaflet - RD5AB302
5
Pressure controls, type KP
Technical data
Ambient temperature −40 → +65°C (+80°C for max. 2 hours).
Contact systems
DIN-approved units: −25 → +65°C (+80°C for max. 2 hours). Max. working pressure LP: PB = 17 bar HP: PB = 32 bar KP 6: PB = 46.5 bar
Low pressure (LP)
Max. test pressure LP: p’ = 20 bar HP: p’ = 35 bar KP 6: p' = 46.5 bar Contact load Alternating current: AC1: 16 A, 400 V AC3: 16 A, 400 V AC15: 10 A, 400 V Max. starting current (L.R.): 112 A, 400 V
High pressure (HP)
Direct current: DC13: 12 W, 220 V control current
Dual pressure (HP/HP)
Properties according to EN 60947: Wire dimensions solid/stranded 0.75 - 2.5 mm2 flexible, w/out ferrules 0.7 - 2.5 mm2 flexible, with ferrules 0.5 - 1.5 mm2 Tightning torque max. 2 NM Rated impulse voltage 4 kV Pollution degree 3 Short circuit protection, fuse 10 Amp Insulation 400 V IP 30/44 Cable connection The cable entry can be used for 6 → 14 mm dia. cables. A Pg 13.5 screwed cable entry can also be used for 6 → 14 mm cable. With 8 → 16 mm cable a standard Pg 16 screwed cable entry can be used.
Dual pressure (LP/HP)
Dual pressure (LP/HP)
Enclosure IP 30 to EN 60529 / IEC 529 Enclosure IP 30 is obtained when the units without top cover are mounted on a flat surface or bracket. The bracket must be fixed to the unit so that all unused holes are covered. IP 44 to EN 60529 / IEC 529 Enclosure IP 44 is obtained when the units with top cover are mounted on a flat surface or bracket. The bracket must be fixed to the unit so that all unused holes are covered. KP pressure controls with auto reset are supplied with top cover. For KP pressure controls with manual reset, the top cover must be separately ordered. IP 55 to EN 60529 / IEC 529 IP 55 is obtained when the KP pressure controls are mounted in an IP 55 enclosure, (code no. 060-0330 for single pressure controls and code no. 060-0350 for dual pressure controls). IP 55 enclosure has to be ordered separately.
6
Technical leaflet - RD5AB302
Danfoss A/S, 05 - 2002
Pressure controls, type KP
Ordering Low pressure (LP) Pressure
Type
High pressure (HP)
Regulating Differential Regulating Differential range ∆p range ∆p bar bar bar bar
Reset Low pressure LP
Code no.
High pressure HP
Contact system
1/4
in. 6 mm flare
1/4
in. ODF solder
6 mm ODF solder
For fluorinated refrigerants Low Low Low Low High High High High Dual Dual Dual Dual Dual Dual Dual Dual Dual
KP 1 KP 1 KP 1 KP 2 KP 5 KP 5 KP 6 KP 6 KP 15 KP 15 KP 15 KP 15 KP 15 KP 15 KP 15 KP 15 KP 15
−0.2 → −0.2 → −0.9 → −0.2 →
−0.2 → −0.2 → −0.2 → −0.9 → −0.9 → −0.2 → −0.2 → −0.2 → −0.9 →
7.5 7.5 7.0 5.0
7.5 7.5 7.5 7.0 7.0 7.5 7.5 7.5 7.0
0.7 → 4.0 0.7 → 4.0 Fixed 0.7 0.4 → 1.5
0.7 → 4.0 0.7 → 4.0 0.7 → 4.0 Fixed 0.7 Fixed 0.7 0.7 → 4.0 0.7 → 4.0 0.7 → 4.0 Fixed 0.7
Low pressure (LP) Pressure
Type
Aut. Aut. Man. Aut. 8 → 32 8 → 32 8 → 42 8 → 42 8 → 32 8 → 32 8 → 32 8 → 32 8 → 32 8 → 32 8 → 32 8 → 32 8 → 32
1.8 → 6.0 Fixed 3 4 → 10 Fixed 4 Fixed 4 Fixed 4 Fixed 4 Fixed 4 Fixed 4 Fixed 4 Fixed 4 Fixed 4 Fixed 4
High pressure (HP)
Regulating Differential Regulating Differential range ∆p range ∆p bar bar bar bar
SPDT Aut. Man.
Aut. Man. Aut. Aut. Aut. Man. Conv.2) Aut. Aut. Conv.2) Conv.2)
Aut. Man. Man. Man. Conv.2) Aut. Man. Conv.2) Conv.2)
SPDT + LP signal
SPDT + LP and HP signal
060-1101 060-11411) 060-1103 060-1120 060-1171 060-1173 060-5190 060-5191 060-1241 060-1243 060-11481) 060-1245 060-1261 060-1265 060-1264 060-1154 060-1220
060-1112
060-1110
060-1111
060-1109 060-1123 060-1177 060-1178
060-1179 060-1180
060-1254
060-1299 060-1284 060-0010
Code no.
Reset Contact system LP / HP
M10 × 0.75 IP 44
1 m cap. tube with M10 × 0.75
For fluorinated refrigerants and R 717 (NH3)
1) 2) 3) 4)
Low
KP 1A
−0.2 → 7.5
0.7 → 4.0
Aut. / -
Low
KP 1A
−0.9 → 7.0
Fixed 0.7
Man. / -
High
KP 5A
8 → 32
High
KP 5A
8 → 32
Fixed 3
- / Man.
Dual
KP 15A
−0.2 → 7.5
0.7 → 4.0
8 → 32
Fixed 4
Aut./Aut.
Dual
KP 15A
−0.2 → 7.5
0.7 → 4.0
8 → 32
Fixed 4
Aut./Man.
Dual
KP 15A
−0.9 → 7.0
Fixed 0.7
8 → 32
Fixed 4
Conv./Conv.2)
1.8 → 6.0
060-11624)
060-11604) 060-11613)
SPDT
060-12304)
- / Aut. SPDT + LP and HP signal SPDT LP signal
060-11533)
060-12313)
060-1295
060-12934)
060-12963)
060-12943) 060-12833)
Pressure controls with gold-plated contacts Conv.: optional automatic or manual reset Enclosure IP 30 Enclosure IP 44
Accessories for KP pressure controls with M10 × 0.75 connections: Weld connections: M10 × 0.75 nut and ∅6 × 150 mm seamless steel pipe, Steel cap. tube: 1 m with 2 × M10 × 0.75 nuts, Steel cap. tube: 1 m with 1 × M10 × 0.75 and G 3/8 nut, Adaptor: M 10 × 0.75 1/4 to 1/8 NPT int. thread, IP 55 enclosure for single pressure controls, IP 55 enclosure for dual pressure controls,
code no. 060-0057 code no. 060-0078 code no. 060-0082 code no. 060-0141 code no. 060-0330 code no. 060-0350
For other accessories: see "Spare parts and accessories", RK0XG.
Danfoss A/S, 05 - 2002
Technical leaflet - RD5AB302
7
Pressure controls, type KP
Pressure control setting with convertible reset
Ordering (continued)
Low press.
Manual reset 1)
Automatic reset
Automatic reset
Manual reset
High press.
Manual reset 1)
Manual reset
Automatic reset
Automatic reset
1)
Factory setting
Pressure controls with DIN 32733 approval 1) Low pressure (LP) Pressure
Type
2)
High pressure (HP)
Code no.
Reset
Regulating Differential Regulating Differential range ∆p range ∆p bar bar bar bar
Contact system LP / HP
DIN approvals
1/4
in. 6 mm flare
6 mm ODF solder
060-11104)
For fluorinated refrigerants Low
KP 1
−0.2 → 7.5
0.7 → 4.0
Aut. / -
SPDT
DWFK 4B06899
060-1101
Low
KP 1
−0.9 → 7
Fixed 0.7
Man. / -
SPDT
DBFK 4B06999
060-1103
Low
KP 1
−0.5 → 3.0
Fixed 0.7
Aut. / -
SPDT
DWFK 4B06899
Low
KP 2
−0.2 → 5
0.4 → 1.5
Aut. / -
SPDT
DWFK 4B07099
High
KP 7W
8 → 32
4 → 10
- / Aut.
SPDT
DWK 4B00199
060-11904) 060-12034)
High
KP 7B
8 → 32
Fixed 4
- / Man.
SPDT
DBK 4B00399
060-11913)
High
KP 7S
8 → 32
Fixed 4
- / Man.
SPDT
DBK 4B00399
060-11923)
Dual
KP 7BS
8 → 32
Fixed 4
Man. / Man.
SPST
DBK 4B00299
060-12003)
Dual
KP 17W
−0.2 → 7.5
0.7 → 4
8 → 32
Fixed 4
Aut. / Aut.
SPDT + LP and HP signal
DWK 4B00599
060-12754) 060-12764)
Dual
KP 17W
−0.2 → 7.5
0.7 → 4
8 → 32
Fixed 4
Aut. / Aut.
SPDT
DWK 4B00599
060-12674)
Dual
KP 17B
−0.2 → 7.5
0.7 → 4
8 → 32
Fixed 4
Aut. / Man.
SPDT
DBK 4B00499
060-12683) 060-12743)
DIN approvals
M10 × 0.75 IP 44
060-1109 060-11174)
060-1120
060-1123
Pressure controls with DIN 32733 approval 1) Low pressure (LP) Pressure
Type
High pressure (HP)
Regulat. Different. Regulat. Different. range ∆p range ∆p bar bar bar bar
Reset
Code no. Contact system
LP / HP
1 m cap. tube with M10 × 0.75
For ammonia Low
KP 1A
-0.2 → 7.5 0.7→4.0
Aut. / -
SPDT
DBFK 4B06899
060-11623) 060-11604)
Low
KP 1A
0.9 → 7 Fixed 0.7
Man. / -
SPDT
DBFK 4B06999
060-11613)
High
KP 7ABS
SPST
DBK 4B00299
060-12053)
8 → 32
Fixed 4 Man./Man.
1)
Meets the requirements in VBG 20 dealing with safety equipment and excess pressures. KP 7 and KP 17 are CE marked acc. to PED, Pressure Equipment Directive. W = Wächter (pressostat), B = Begrenzer (pressure control with ext. reset), S = Sicherheitsdruckbegrenzer (pressure control with int. reset). A bellows rupture in inner bellows will cause the refrigeration plant compressor to stop. A rupture of the outer bellows will cause the stop pressure to fall approx. 3 bar under the set value. 3) Enclosure IP 30. 4) Enclosure IP 44. 2)
8
Technical leaflet - RD5AB302
Danfoss A/S, 05 - 2002
Pressure controls, type KP
Design / Function
Capillary tube
Key sketch of KP pressure control
flare
Capillary tube for KP 1A, 5A and 15A
KP 1
1. Low pressure (LP) setting spindle 2. Differential setting spindle, LP 3. Main arm 5. High pressure (HP) setting spindle 7. Main spring 8. Differential spring 9. Bellows 10. LP connection 11. HP connection 12. Switch 13. Terminals 14. Earth terminal 15. Cable entry 16. Tumbler 18. Locking plate 19. Arm 30. Reset button
flare KP 15
The switch in the KP has a snap-action function and the bellows moves only when the cut-in or cut-out value is reached. The bellows becomes connected to the low or high pressure side of the plant through connection (10) or (11).
Danfoss A/S, 05 - 2002
Technical leaflet - RD5AB302
The design of the KP affords the following advantages: − high contact load − ultra-short bounce time − high resistance to pulsation − vibration resistance up to 4 g in the range 0-1000 Hz − long mechanical and electrical life
9
Pressure controls, type KP
Design (continued)
KP 1, KP 2, KP 7 and KP 17 units with designation W, B or S have been tested and approved by J (Technischer Über-wachungs Verein, Federal Republic of Germany) in accordance with DIN 32733. W = Wächter (pressure control) B = Begrenzer (pressure control with external reset) S = Sicherheitsdruckbegrenzer (pressure control with internal reset). KP 7 and KP 17 have a double bellows: an outer bellows and a regulating bellows. When system pressure exceeds the set value, the KP will automatically stop the plant. The double bellows system prevents loss of charge in the event of bellows rupture. A rupture in the outer bellows will cause the control cut-out pressure to fall to about 3 bar under the set value, thus providing a fail-safe function.
Versions with designation W or AW cut in again automatically when the pressure has fallen to the set value minus the differential. Versions with designation B or AB can be cut in manually with the external reset button when the pressure in KP 1 has raised 0.7 bar above set value and in KP 7 has fallen 4 bar under the set value. Versions with designation S or AS can be cut in manually with the internal reset arm when the pressure has fallen 4 bar under the set value. All KP pressure controls, including those which are DIN-approved, operate independently of changes in the ambient temperature around the control housing. Therefore the set cut-out pressure and differential are held constant provided the permissible ambient temperatures are not exceeded.
flare
KP 7W, flare
or 1/4 in.
KP 7W, solder
1. Pressure setting spindle 2. Differential setting spindle 3. Main arm 5. Pressure setting spindle, DBK 15. Cable entry 18. Locking plate 19. Arm 25. Int. reset arm 30. Ext. reset button
10
flare
KP 7BS
Technical leaflet - RD5AB302
Danfoss A/S, 05 - 2002
Pressure controls, type KP
Terminology
Reset 1. Manual reset: Units with manual reset can only be reset during operation by activation of the reset button. 2. Automatic reset: After operational stop, these units reset automatically. 3. Convertible reset: Units with optional reset can be activated by automatic and/or manual reset. Permissible working pressure The permissible working pressure is determined by the pressure that can be safely allowed in the refrigerating system or any of the units within it. The permissible working pressure is designated PB (Der zulässige Betriebsüberdruck).
Setting
Pressure controls with automatic reset - LP: Set the LP start pressure on the "CUT-IN" scale (range scale). One rotation of the low pressure spindle ∼ 0.7 bar. Set the LP differential on the "DIFF" scale. One rotation of the differential spindle ∼ 0.15 bar. The LP stop pressure is the LP start pressure minus the differential. Note: The LP stop pressure must be above absolute vacuum (pe = −1 bar)! If with low stop pressure the refrigeration compressor will not stop, check to ensure that the differential value has not been set too high!
Danfoss A/S, 05 - 2002
Technical leaflet - RD5AB302
Test pressure The test pressure is the pressure used in strength tests and/or leakage tests on refrigerating systems or individual parts in systems. The test pressure is designated p’. "Snap function" A certain contact force is maintained until irrevocable "snap" is initiated. The time during which the contact force approaches zero is thus limited to a very few milliseconds. Therefore contact bounce cannot occur as a result of, for example, slight vibrations, before the cut-out point. Contact systems with "Snap function" will change over even when micro-welds are created between the contacts during cut-in. A very high force is created during cut-out to separate the contacts. This force immediately shears off all the welds. Thus the cut-out point of the unit remains very accurate and completely independent of the magnitude of the current load. Pressure controls with automatic reset - HP: Set the HP pressure on the "CUT-OUT" scale. One rotation of the HP spindle ∼ 2.3 bar. Set the HP differential on the "DIFF" scale. One rotation of the differential spindle ∼ 0.3 bar. The HP start pressure is the HP stop pressure minus the differential. Start and stop pressures for both the LP and HP sides of the system should always be checked with an accurate pressure gauge. Pressure controls with manual reset Set the stop pressure on "CUT-OUT" scale (range scale). Low pressure controls can be manually reset when the pressure is equal to the stop pressure plus the differential. High pressure controls can be manually reset when the pressure is equal to the stop pressure minus the differential.
11
Pressure controls, type KP
Dimensions and weights Flare connection
KP 1, 2, 5, 6, 7B, 7S and 7W
KP with top cover
KP 15 and 17W
M10 × 0.75 connection
KP 1A, 2A and 5A
KP with IP 55 enclosure
KP 15A, 7 AS and 7ABS
KP with IP 55 enclosure
Solder connection
IP 55 enclosure
KP 1, 2, 5, 7B, 7S and 7W
KP 15, 17W
IP 55 enclosure
Weld nipple for KP-A
12
Weight KP 1, 2, 5 and 7: approx. 0.3 kg KP 15, 17 and 7BS: approx. 0.5 kg KP 1A and 5A: approx. 0.3 kg KP 15A and 7ABS: approx. 0.5 kg
Technical leaflet - RD5AB302
Danfoss A/S, 05 - 2002
Pressure controls, differential pressure controls Type RT Introduction
An RT pressure control contains a pressure operated single-pole changeover contact, the position of which depends on the pressure in the inlet connection and the set scale value. The RT series includes pressure controls for general applications within industrial and marine refrigeration. The RT series also includes differential pressure controls, pressure controls for neutral zone regulation, and special pressure controls with gold-plated contact surfaces for PLC applications.
Features
Technical data
• Waterproof versions
• Suitable for alternating and direct current
• Wide regulating range
• Interchangeable contact system
• Wide range of units for industrial and marine applications
• Special versions for PLC applications
Cable connection Pg 13.5. Cable diameter 6 → 14 mm
Properties according to EN 60947: Wire dimensions solid/stranded 0.2 - 2.5 mm2 flexible, w/out ferrules 0.2 - 2.5 mm2 flexible, with ferrules 0.2 - 1.5 mm2 Tightening torque max. 1.5 NM Rated impulse voltage 4 kV Pollution degree 3 Short circuit protection, fuse 10 Amp Insulation 400 V IP 45/66
Enclosure IP 66 to IEC 529, except for versions with ext. reset which are to IP 54. Ambient temperature −50 to +70°C for pressure control housing.
RT 6W, 6B, 6S
RT 6AW, 6AB, 6AS
RT 30AW, 30AB, 30AS
RT 36B, 36S
•
•
•
•
•
• • •
• •
•
•
• •
•
• •
•
•
•
•
RT 262A
RT 5A
•
RT 260A
RT 5
•
RT 200L
RT 1AL
•
RT 200
RT 1A
•
RT 117L
RT 1
Approvals
RT 117
Switches See "Ordering, switches".
•
•
•
•
•
•
•
•
•
•
•
•
Lloyd’s Register of Shipping, UK F Germanischer Lloyd, Germany •
•
•
•
• •
•
•
•
•
•
•
•
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•
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•
•
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Danfoss A/S, 05 - 2002
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J Vd TÜV, Germany •
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•
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Nasthol, Russian Federation Det norske Veritas, Norway
• •
DEMKO, Denmark
•
Bureau Veritas, France P Polski Rejestr Statków, Poland
• •
•
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RINA, Registro Italiano Navale, Italy
•
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RMRS, Russian Maritime Register of Shipping DIN CERTCO, Germany
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Technical leaflet - RD5BA302
•
NKK, Japan Korean Register of Shipping •
•
•
CE marked according to 60947-4, -5 CE marked acc. to PED 97/23/EC category IV, safety equipm.
13
Pressure controls, differential pressure controls, type RT
Materials in contact with the medium
Ordering
W. no.
To DIN
RT 117, RT 117L RT 200, RT 200L
Type
Stainless steel 18/8 Stainless steel 17/7 Brass Brass
Material
1.4306 1.4568 2.0402 2.0321
17440 17224 1782 17660
RT 1A, RT 1AL RT 5A, RT 5AL RT 260A, RT 262A RT 265A
Stainless steel 18/8 Plain carbon steel Deep drawing steel Plain carbon steel Case-hardened steel Aluminium
1.4306
17440 17223 1624 1652 17210 1712
RT 1, RT 5
Stainless steel 18/8 Plain carbon steel Deep drawing steel
1.4306
RT 6W, 6B, 6S RT 6AW, 6AB, 6AS
RT 30AW, 30AB, 30AS RT 36B, 36S
1.0338 1.0402 1.0401 3.0255
Comments
Zn5Cro (RT 1A, RT 1AL only) Nickel-plated, tinned Zn5Cro Nickel-plated
1.0338
17440 17223 1624
Zn5Cro (RT 1 only) Nickel-plated, tinned
Stainless steel 18/8 Deep drawing steel Case-hardened steel Free-cutting steel Plain carbon steel Aluminium
1.4306 1.0338 1.1141 1.0718 1.0402 3.0255
17440 1624 1652 1651 1652 1712
Nickel-plated, tinned Nickel-plated Nickel-plated Zn5Cro (RT 6AW, 6AB, 6AS) (RT 6AW, 6AB, 6AS only)
Stainless steel 18/8 Stainless steel 17/7 Deep drawing steel Stainless steel 18/8 STW 22 Free-cutting steel
1.4306 1.4568 1.0338 1.4305 1.0332 1.0718
17440 17224 1624 17440 1614 1651
Nickel-plated, tinned Nickel-plated Nickel-plated
Pressure controls for fluorinated refrigerants Pressure
Type
Regulation range
bar
Low
RT 1 RT 200
High
RT 5 RT 117
1)
Differential ∆p
Reset
bar
Max. working pressure PB
Max. test pressure p'
bar
bar
Code no. Connection 1/4 in. / 6mm flare
– 0.8 → 5
0.5 → 1.6
Aut.
22
25
017-5245
– 0.8 → 5
Fixed 0.5
Man.
22
25
017-5246
0.2 → 6
0.25 → 1.2
Aut.
22
25
4 → 17
1.2 → 4
Aut.
22
25
017-5250
4 → 17
Fixed 1.2
Man.
22
25
017-5251
10 → 30
1→4
Aut.
42
47
G 3/8 A 1)
017-5237
017-5295
BSP ext. thread, ISO 228/1.
Safety - Pressure controls for R 717 (NH3) and fluorinated refrigerants Pressure
Type
Regulation range
High 1)
14
RT 1A
RT 5A
Reset
Max. working pressure PB
Max. test pressure p'
Code no. Connection
bar
bar
∅ 6 mm
G 3/8 A 1) + weld nipple ∅ 6.5/10 mm
– 0.8 → 5
0.5 → 1.6
Aut.
22
25
017-5019
017-5001
– 0.8 → 5
Fixed 0.5
Man.
22
25
017-5027
– 0.8 → 5
1.3 → 2.4
Aut.
22
25
bar
Low
Differential ∆p
bar
Cutting ring
017-5002 017-5007
4 → 17
1.2 → 4
Aut.
22
25
017-5052
017-5046
4 → 17
Fixed 1.2
Man.
22
25
017-5061
017-5047
BSP ext. thread, ISO 228/1.
Technical leaflet - RD5BA302
Danfoss A/S, 05 - 2002
Pressure controls, differential pressure controls, type RT
Safety pressure controls w/ DIN 32733 appr. and CE marked acc. PED, Pressure Equipment Directive*) Press.
Type
Regulation range
Different. Reset ∆p
Cutting ring G 3/8 A 1) + G 1/2 A 1) weld nipple ∅ 6 mm ∅6.5/10 mm
bar
bar
Fixed 0.2 Man.
22
25
017-5258
Fixed 0.2 Man.
22
25
017-5259
Aut.
34
38
017-5031
Fixed 1
Man.
34
38
017-5034
Fixed 1
Man.
34
38
017-5075
bar
*) Meets the requirements in VBG 20 on safety equipment and excess pressures. W = Wächter (pressure control). B = Begrenzer (pressure control with external reset). S = Sicherheitsdruckbegrenzer (pressure control with internal reset). A rupture in the bellows system of the unit will cause the compressor to stop.
Code no. Connection 1/4 in./ 6 mm flare
bar
RT 36B 2)
0 → 2.5
RT 36S 2)
0 → 2.5
RT 6W 2)
5 → 25
Fixed 3
High RT 6B 2)
10 → 28
RT 6S 2)
10 → 28
High
Max. Max. test working pressure pressure p' PB
RT 30AW 3)
1 → 10
Fixed 0.8 Aut.
22
25
017-5187
High RT 30AB 3)
1 → 10
Fixed 0.4 Man.
22
25
017-5188
RT 30AS 3)
1 → 10
Fixed 0.4 Man.
RT 6AW 3)
5 → 25
High RT 6AB 3) RT 6AS 3) 1) 2) 3)
22
25
Aut.
34
38
017-5131
017-5032
10 → 28
Fixed 1.5 Man.
34
38
017-5133
017-5035
10 → 28
Fixed 1.5 Man.
34
38
017-5146
017-5076
Fixed 3
017-5189
BSP ext. thread, ISO 228/1. Pressure controls for fluorinated refrigerants. Pressure controls for R 717 (NH3) and fluorinated refrigerants.
Pressure controls with adjustable dead zone for R 717(NH3) and fluorinated refrigerants Pressure
Type
Regulation range
Differential
Dead zone NZ
Max. working pressure
Max. test pressure
∆p bar
∆p bar
PB bar
p' bar
∅ 6 mm
G 3/8 A 1) + weld nipple ∅ 6.5 / ∅ 10
Fixed 0.2
0.2 → 0.9
22
25
017L0016
017L0033
0.2 → 6
Fixed 0.25 0.25 → 0.7
22
25
RT 5AL2)
4 → 17
Fixed 0.35 0.35 → 1.4
22
25
RT 117L3)
10 → 30
1 → 3.0
42
47
bar Low
– 0.8 → 5
RT 1AL2) RT 200L3)
High
Fixed 1.0
1) BSP ext thread, ISO 228/1. 2) Pressure controls for (R 717 NH ) and fluorinated 3 3) Pressure controls for fluorinated refrigerants 2) Without weld nipple.
Ordering
Code no. Connection Cutting ring
017L0032 017L000172)
017L0040 017L0042 2)
refrigerants
Differential pressure controls for R 717(NH3) and fluorinated refrigerants Type
RT 260A
RT 262A RT 265A 3) 1) 2) 3)
Regulation Differential Operating range range for LP bellows ∆p bar
∆p bar
0.5 → 4
Fixed 0.3
0.5 → 4
Fixed 0.3
Max. Max. working test pressure pressure
bar
PB bar
p' bar
–1 → 18
22
25
–1 → 18
22
25
Code no. Connection G 3/8 A 1) + weld nipple ∅ 6.5 / ∅ 10 mm
Cutting ring ∅ 6 mm 017D0014
017D0021 017D0022 2)
0.5 → 6
Fixed 0.5
–1 → 36
42
47
017D0015
017D0023
1.5 → 11
Fixed 0.5
–1 → 31
42
47
017D0016
017D0024
0.1 → 1.5
Fixed 0.1
–1 → 9
11
13
017D0013
017D0025
1→6
Fixed 0.5
–1 → 36
42
47
017D0072
BSP ext thread, ISO 228/1. Man. reset. Filter monitor: Alarm ∆p = 0.8 bar, cut-out ∆p = 1 bar (factory setting).
Differential pressure controls with adjustable dead zone for R 717(NH3) and fluorinated refrigerants Type
RT 262AL
Regulation range
Differential
∆p bar
∆p bar
0.1 → 1.5
Fixed 0.1
1)BSP ext thread, ISO 228/1. 2)Differential pressure control
Danfoss A/S, 05 - 2002
Dead zone NZ
Code no.
Operating range for LP bellows
Max. working pressure
Max. test pressure
bar
bar
PB bar
p' bar
G 1/2 A 1 ) + weld nipple ∅ 6.5/10 mm
0.1 → 0.33
−1 → 9
11
13
017D0043 2)
Connection
for R 717 (NH3) and fluorinated refrigerants.
Technical leaflet - RD5BA302
15
Pressure controls, differential pressure controls, type RT
Ordering (continued)
Special versions RT can be supplied with special switches as follows.
When ordering, please state 1. Type 2. Code no. of standard unit 3. Code no. of special switch
Switches 1) Version
Symbol
Standard
Description
Contact rating
Single-pole changeover switch with terminal board proof against leakage current. Fitted in all standard versions of type RT. Snap action changeover contacts. SPDT
With Man. reset SPDT With Man. reset
Alternating current 2) Ohmic: AC1 = 10 A, 400 V
Inductive: AC3 = 4 A, 400 V AC15 = 3 A, 400 V
Fitted in DIN pressure controls. For manual reset of unit after contact changeover on rising pressure. For HP units prepared for reset facility.
Dir. current DC13 = 12 W, 220 V
Code no. 017-4030
017-4230 017-4042 with Man. reset
For manual reset of unit after contact changeover on falling pressure. For LP units prepared for reset facility.
017-4041 with Man. reset
Single-pole changeover switch with dead zone and terminal board proof against leakage current.
Available only as a component part of RT controls with adjustable dead zone
SPDT With dead zone
SPDT
Standard
SPDT With dead zone
SPDT Cuts in two circuits simultaneously Cuts out two circuits simultaneously
With non-snap action changeover contacts 1) 2) 3)
SPST
SPST
Single-pole changeover switch with gold plated (oxide-free) contact surfaces. Increases cut-in reliability on alarm and monitoring systems, etc. Snap action changeover contacts. Terminal board proof against leakage current. Single-pole changeover switch with dead zone and gold plated (oxide-free) contact surfaces. Increases cut-in reliability on alarm and monitoring systems, etc. Snap action changeover contacts. Terminal board proof against leakage current.
Single-pole changeover switch with non-snap action changeover contacts.
017-4240
Inductive: AC3 = 2 A, 400 V AC15 = 1 A, 400 V Dir. current DC13 = 12 W, 220 V
Single-pole changeover switch that cuts in Alternating current 2) Ohmic: two circuits simultaneously on rising pressure. Snap action changeover contacts. AC1 = 10 A, 400 V Terminal board proof against leakage current. Inductive: Single-pole changeover switch that cuts out AC3 = 3 A, 400 V two circuits simultaneously on rising AC15 = 2 A, 400 V pressure. Snap action changeover contacts. Terminal board proof against leakage current. Dir. current DC13 = 12 W, 220 V 3)
Alternating or direct current 25 VA, 24 V
Available only as a component part of RT controls with adjustable dead zone 017-4034
017-4036
017-0181
SPDT
RT pressure controls meet the conditions of EN 60947-2-9. Max. starting current (L.R.) = 7 × AC 3. If current is led through the contacts 2 and 4, i.e. terminals 2 and 4 connected but not terminal 1, the max. permissible load is increased by 90 W, 220V.
The switches are shown in the position they assume on falling pressure, i.e. after downward movement of the RT main spindle.
16
Alternating current 2) Ohmic: AC1 = 10 A, 400 V
Technical leaflet - RD5BA302
The setting pointer of the control shows the scale value at which contact changeover occurs on falling pressure. An exception is RT with switch code no. 017-4042 with Man. reset, where the setting pointer shows the scale value at which contact changeover occurs on rising pressure.
Danfoss A/S, 05 - 2002
Pressure controls, differential pressure controls, type RT
Design Function
5. Setting knob 9. Regulation range scale 10. Loop terminal 11. Pg 13.5 screwed cable entry 12. Main spring 14. Terminals 15. Main spindle 16. Switch 17. Guide bush 18. Contact arm 19. Differential setting nut 23. Bellows element 25. Fixing hole 27. Connection 38. Earth terminal 39. Blow-out disc 44. Pressure setting spindle
Pressure control type RT
Key sketch RT pressure control
RT pressure control
The bellows in the RT pressure control is connected to the low or high pressure side of the controlled system via the connection. By turning the setting knob (5) the main spring (12) can be set to balance the pressure in the bellows. A rise in pressure compresses the bellows and moves the main spindle (15) upwards until spring and bellows pressure are in equilibrium. The main spindle (15) is fitted with a guide bush (17) and a differential pressure setting nut (19) that together transfer the main spindle movement to the switch (16). The RT 6W, 6B, 6S, RT 6AW, 6AB, 6AS, RT 30AW, 30AB, 30AS, RT 36B, 36S are equipped with a double bellows (an outer bellows and a regulating bellows). These units have been tested and approved by J (Technischer Überwachungs Verein, Germany) according to DIN 32733. W = Wächter (pressure controls) B = Begrenzer (pressure controls with external reset) S = Sicherheitsdruckbegrenzer (pressure controls with internal reset).
Danfoss A/S, 05 - 2002
Technical leaflet - RD5BA302
General for DIN 32733 approved units 1. The units are equipped with a double bellows system. When pressure in the plant exceeds the set value, the unit will automatically stop the plant. The double bellows system prevents loss of system charge in the event of bellows rupture. 2. Versions with designation W or AW cut in again automatically when the pressure has fallen to the set value minus the differential. 3. Versions with designation B or AB are cut in manually with the external reset button. This is possible when the pressure has fallen by a value corresponding to the differential under the set value. 4. Versions with designation S or AS can be cut in manually with the internal reset arm when the pressure has fallen 4 bar under the set value. As laid down by DIN 32733 requirements, if a rupture occurs in the regulating bellows of the unit the refrigerating system compressor will be stopped and can only be restarted when the pressure control has been replaced. A rupture in the outer bellows will cause the cut-out pressure of RT 36 to fall 2.5 bar, and the cut-out pressure of RT 6 and RT 30 to fall 4.5 bar under the set value. This means that the unit cuts out at normal condensing pressure and thus provides a failsafe function. All RT pressure controls, including those which are DIN 32733 approved, operate independently of changes in the ambient temperature around the control housing. Therefore the set cut-out pressure and differential are held constant provided the permissible ambient temperatures are not exceeded.
17
Pressure controls, differential pressure controls, type RT
Design Function (continued)
5. Setting knob 9. Regulation range scale 11. Pg 13.5 screwed cable entry 12. Main spring 15. Main spindle 16. Switch 17. Upper guide bush 18. 18a, 18b. Contact arm 20. Lower guide bush 23. Bellows element 25. Fixing hole 27. Connection 38. Earth terminal 39. Blow-out disc 40. Neutral zone setting nut 44. Pressure setting spindle
Pressure control with dead zone, type RT L
Key sketch RT L pressure control
RT L pressure controls are fitted with a switch (17-4032) with an adjustable neutral zone. This enables the units to be used for floating control. The neutral zone switch contact arms (18a) and (18b) are operated by the spindle guide bushes (17) and (20).
18
Technical leaflet - RD5BA302
RT L pressure control
The upper guide bush (17) is Fixed while the lower guide bush (20) can be moved up or down by the setting nut (40). In this way the neutral zone can be varied between a minimum value (equal to the mechanical differential of the unit) and a maximum value (depending on the type of RT unit).
Danfoss A/S, 05 - 2002
Pressure controls, differential pressure controls, type RT
Design Function (continued)
3. LP connection 4. LP bellows element 5. Setting disc 9. Regulation range scale 10. Coil clamp 11. Pg 13.5 screwed cable entry 12. Main spring 14. Terminals 15. Main spindle 16. Switch 17. Upper guide bush 18. Contact arm 20. Lower guide bush 24. HP bellows element 25. Fixing hole 34. HP connection 38. Earth terminal 39. Blow-out disc
Differential pressure control, type RT
Key sketch RT differential pressure control
RT differential pressure control
An RT differential pressure control contains a single-pole changeover switch that makes or breaks depending on the pressure differential between two counteracting bellows elements (LP and HP). Differential pressure controls are used primarily as protection against too low a differential pressure across liquid circulation pumps. A secondary application is the safeguarding of lubricating oil pressure in refrigeration compressors. The function of the pressure control is conditional only on the differential pressure, i.e. the difference in pressure between the two counteracting bellows, whereas it is independent of the absolute pressure on both bellows. The bellows (4) and (24) are respectively connected to the LP port (lowest pressure) and the HP port (highest pressure). The main spring (12) can be set for different differential pressures by the setting disc (5).
Danfoss A/S, 05 - 2002
Technical leaflet - RD5BA302
If the differential pressure between highest and lowest pressures falls, the spindle (15) moves downwards and via the upper guide bush (17) actuates the switch contact arm (18). The reverse function occurs if the differential pressure rises.
For RT 260A controls used on screw compressors the following applies 1) 1. Max. pressure in low pressure bellows ∼ condensing pressure = 21 bar. 2. Max. pressure in high pressure bellows ∼ lubricating oil pressure = 24 bar. 3. Differential between condensing pressure and lubricating oil pressure must not exceed 3 bar. 4. Pressure change in the low and high pressure bellows from start to normal operation must not exceed 8 bar. 1)
Since the operating conditions given, are outside the operating range of the unit, the life of the bellows will be reduced to approx. 10 000 operations as against approx. the normal 400 000.
19
Pressure controls, differential pressure controls, type RT
Terminology
Floating control A form of delayed control where the correcting element (e.g. valve, damper, or similar) moves towards one extreme position at a rate independent of the magnitude of the error when the error exceeds a definite positive value, and towards the opposite extreme position when the error exceeds a definite negative value. Hunting Periodic variations of the controlled variable from the Fixed reference. Neutral zone The interval between the make points of the two contacts.
Setting
RT with automatic reset - LP The knob is used to set the lowest pressure at which the contact system must be activated (cut-out or cut-in). This value can be read on the main scale of the unit. The differential roller must be used to set the differential. Highest activating pressure = lowest activating pressure + set differential. RT with manual reset - LP RT pressure controls RT 1 and RT 1A are obtainable in versions with min. reset. When the pressure falls to the setting value the pressure control cuts out. Manual reset becomes possible when the pressure in the bellows system has risen to a value corresponding to the set value + the differential. On falling pressure the follower activates the contact system arm and the contact changes over. The scale is calibrated so that the scale value corresponds to contact changeover on falling pressure.
20
Technical leaflet - RD5BA302
"Snap function" A certain contact force is maintained until irrevocable "snap" is initiated. The time during which the contact force approaches zero is thus limited to a very few milliseconds. Therefore contact bounce cannot occur as a result of, for example, slight vibrations, before the cut-out point. Contact systems with "Snap function" will change over even when micro-welds are created between the contacts during cut-in. A very high force is created during cut-out to separate the contacts. This force immediately shears off all the welds. Thus the cut-out point of the unit remains very accurate and completely independent of the magnitude of the current load.
RT with automatic reset - HP The knob can be used to set the lowest pressure at which the contact system must be activated (cut-out or cut-in). This value can be read on the main scale of the unit. The differential must be set with the differential roller. Highest activating pressure = lowest activating pressure + set differential. RT with manual reset - HP RT pressure controls RT 5 and RT 5A are obtainable in versions with max. reset. When the pressure has risen to the set value the pressure control cuts out. Manual reset only becomes possible when the pressure has fallen to a value corresponding to the set pressure minus the differential. The differential roller is then used as a follower. On rising pressure the differential roller activates the contact system arm and the contact changes over. The scale is calibrated so that the scale values correspond to contact changeover on rising pressure, which is opposite to RT units with automatic reset.
Danfoss A/S, 05 - 2002
Pressure controls, differential pressure controls, type RT
Dimensions and weight Weight approx. 1 kg
RT pressure control housing
RT 1A, 1AL
RT 1
RT 1A, 1AL
RT 6, 36
RT 260A
Danfoss A/S, 05 - 2002
RT 5A, 5AL, 6A
RT 30A
RT 262A
Technical leaflet - RD5BA302
RT 5
RT 5A, 5AL, 6A
RT 117, 117L, 200, 200L
RT 260A, 262A
21
Differential pressure controls Type MP 54, 55 and 55A Introduction
MP 54 and MP 55 oil differential pressure controls are used as safety switches to protect refrigeration compressors against low lubricating oil pressure. If the oil pressure fails the oil differential pressure control stops the compressor after a certain time period. MP 54 and 55 are used in refrigerating systems using fluorinated refrigerants. MP 55A is used in refrigerating systems with R 717 (NH3). MP 55A can also be used in systems with fluorinated refrigerant. MP 54 has a fixed differential pressure setting. It also incorporates a thermal time relay with a fixed release time setting. MP 55 and 55A have adjustable differential pressure and are available both with and without thermal time relay.
Features
• Wide regulating range Can be used for deep freeze, refrigeration and air conditioning plant • Can be used for all normal fluorinated refrigerants
Approvals
Materials in contact with the medium
Danfoss A/S, 10 - 2001
• Suitable for both alternating and direct current • Screwed cable entry for cables from 6 to 14 mm diameter • Small contact differential
• Electrical connection at the front of the unit
• Meets the requirements of EN 60947
M DEMKO, Denmark O NEMKO, Norway W FIMKO, Finland DSRK, Deutsche-Schiffs-Revision und -Klassifikation, Germany P Polski Rejestr Statków, Poland F Germanischer Lloyd, Germany
EZU, The Czech Republic RINA, Italy CE mark according to EN 60947-5
Unit type
Versions having UL and CSA approvals can be supplied to special order.
Material
MP 54 MP 55
Stainless steel 19/11, no. 1.4306 to DIN 17440 Deep-drawn steel plate, no. 1.0338 to DIN 1624 Free cutting steel, no. 1.0718 to DIN 1651
MP 55A
Stainless steel 19/11, no. 1.4306 to DIN 17440 Deep-drawn steel plate, no. 1.0338 to DIN 1624 Free cutting steel, no. 1.0401 to DIN 1652
Technical leaflet - RD5CA302
23
Differential pressure controls, type MP 54, 55 and 55A
Technical data
Control voltage 230 V or 115 V a.c. or d.c.
Contact loads Type A: On time relay output contacts M-S: AC15: 2 A, 250 V DC13: 0,2 A, 250 V Type B without time relay: AC15: 0,1 A, 250 V DC13: 12 W, 125 V
Permissible voltage variation +10 → −15% Max. working pressure PB = 17 bar Max. test pressure p’ = 22 bar
Type C without time relay: AC1: 10 A, 250 V AC3: 4 A, 250 V DC13: 12 W, 125 V
Temperature compensation The time relay is temperature-compensated in the range −40 to +60°C
Properties according to EN 60947: Wire dimensions solid/stranded 0.2 - 1.5 mm2 flexible, w/out ferrules 0.2 - 1.5 mm2 flexible, with ferrules 0.2 - 1 mm2 Tightening torque max. 1.2 NM Rated impulse voltage 4 kV Pollution degree 3 Short circuit protection, fuse 2 Amp Insulation 250 V IP 20
Screwed cable entry Pg 13.5 Cable diameter 6 → 14 mm
Max. bellows temperature 100°C Enclosure IP 20 to IEC 529 Ordering
For fluorinated refrigerants
Type
MP 54
MP 55
Differential
Switch differential max.
Operation range, LP side
Time relay release time s
∆p bar
∆p bar
bar
Fixed 0.65
0.2
−1 → +12
Contact load (see technical data)
0 2)
Code no. Connection 1/4
in./6 mm Flare
B
060B0297
1 m cap.tube Cutting ring 1/4 in. 6 mm ODF solder
Fixed 0.65
0.2
−1 → +12
45
A
060B0166
Fixed 0.9
0.2
−1 → +12
60
A
060B0167
Fixed 0.65
0.2
−1 → +12
90
A
060B0168
Fixed 0.65
0.2
−1 → +12
120
A
060B01693)
0.3 → 4.5
0.2
−1 → +12
45
A
060B0170
060B0133
0.3 → 4.5
0.2
−1 → +12
60
A
060B0171
060B0134
0.3 → 4.5
0.2
−1 → +12
60
A
060B01781)
0.3 → 4.5
0.2
−1 → +12
90
A
060B0172
0.3 → 4.5
0.2
−1 → +12
120
A
060B0173
0.3 → 4.5
0.2
−1 → +12
0 2)
B
060B0299
0.65 → 4.5
0.4
−1 → +12
0 2)
C
060B02944)
060B0188
060B0136 060B0295
For fluorinated refrigerants and R717 (NH3)
Type
MP 55A
Operation range, LP side
Time relay release time
bar
Differential
Switch differential
∆p bar
max. ∆p bar
0.3 → 4.5
0.2
−1 → +12
s 45
0.3 → 4.5
0.2
−1 → +12
0.3 → 4.5
0.2
−1 → +12
0.3 → 4.5
0.2
−1 → +12
0.3 → 4.5
0.2
−1 → +12
0.3 → 4.5
0.2
−1 → +12
Contact load (see technical data)
Code no. Connection ∅ 6,5 / ∅ 10 mm weld nipple
Cutting ring
A
060B0174
060B0182
60
A
060B0175
060B0183
60
A
060B0179 1)
90
A
060B0176
060B0184
120
A
060B0177
060B0185
B
060B0298 2) 060B0296
0 2)
6 mm
1)
With operational light that remains on during normal operation. Note: If the operational light goes out, the compressor should not run longer than the release time. 2) Versions without time relay are for applications where an external time relay is required - perhaps with a different release time than the one specified. 3) 060B0169 meets Copeland specifications. UL-approved versions can be supplied. 4) Approved according to EN 60947-4, -5.
24
Technical leaflet - RD5CA302
Danfoss A/S, 10 - 2001
Differential pressure controls, type MP 54, 55 and 55A
Design
The operation of the pressure control is conditional only on the differential pressure, i.e. the difference in pressure between the two counteracting bellows, whereas it is independent of the absolute pressure acting on both bellows. The MP 55 and 55A can be set for different differential pressures by the setting disc (3). The set differential pressure can be read from the internal scale. The MP 54 has a fixed differential and has no pressure setting disc. The factory-set differential pressure is stamped on the front plate of the control.
1. Connection to pressure side of lubrication system, OIL 2. Connection to suction side of refrigeration plant, LP 3. Setting disc 4. Reset buttom 5. Test device
Terminology
MP 55
Differential range The pressure difference between LP and OIL connections within which the control can be set to operate.
Contact differential The pressure rise above the set differential pressure (scale reading) necessary to cut off current to the time relay.
Scale reading The differential between the oil pump pressure and the pressure in the crankcase that exists at the moment the contact system cuts in current to the time relay on falling oil pressure.
Release time The period for which the differential pressure control allows the compressor to run with too low an oil pressure during start-up and operation.
Operating range The pressure range on the LP connection within which the control can operate. Function
If there is no oil pressure on starting, or if the oil pressure falls below the set pressure during operation, the compressor will stop after the release time has elapsed. The electrical circuit is divided into two completely separate circuits, a safety circuit and an operational circuit.
The timer (e) in the safety circuit is activated when the effective lubricating oil pressure, the oil differential pressure (the difference between the oil pump pressure and suction pressure), is lower than the set value. The timer is deactivated when the oil differential pressure is more than the set value plus the contact differential.
Electrical diagram
Danfoss A/S, 10 - 2001
Technical leaflet - RD5CA302
25
Differential pressure controls, type MP 54, 55 and 55A
Function (continued)
The two diagrams below explain the terms "oil differential pressure" and "contact differential", both have to be considered when using oil differential pressure controls.
The first diagram shows the function of the differential control during start; the second shows the function of the control during operation.
Pos. A: Normal start-up The lubricating oil pressure is built up during start to the set/fixed differential plus the contact differential, before the timer cuts out (in this example, after 45 seconds). At point A contacts T1-T2 open and timer (e) is stopped, i.e. normal lubricating oil conditions for the compressor have been established. Pos. B: The lubricating oil pressure does not reach the set/fixed differential plus the contact differential before the timer period elapses. At point B the timer cuts out operational circuit L-M and the compressor stops. If a signal source is connected to terminal S, it will be activated. Restart can only be performed after about 2 minutes by activation of the reset button, provided the cause of the fault has been determined.
On start-up
Pos. C: The lubricating oil pressure falls during operation to a value lower than the set/fixed differential. At point C, safety circuit T1-T2 cuts in and the timer is activated. Pos. D: The lubricating oil pressure reaches the set/fixed ifferential plus the contact differential before the timer period elapses. At point D, safety circuit T1-T2 cuts out and the timer is stopped, i.e. normal lubricating oil conditions for the compressor have been established. Pos. E: The lubricating oil pressure falls to a value lower than the set/fixed differential during operation. At point E, safety circuit T1-T2 cuts in and the timer is activated. Pos. F: The lubricating oil pressure remains lower than the set/ fixed differential. At point F the timer cuts out operational circuit LM and the compressor stops. If a signal source is connected to terminal S, it will be activated. Restart can only be performed after about 2 minutes by activation of the reset button, provided the cause of the fault has been determined. After start-up It is important that a function check should be made to ensure that the differential pressure control is operating as it should. This check can be made by pressing the test device (inside the unit on the left hand side). When the test device is pressed down and held in this position the compressor motor should stop after the release time determined by the time relay has elapsed.
During operation
26
Technical leaflet - RD5CA302
Danfoss A/S, 10 - 2001
Differential pressure controls, type MP 54, 55 and 55A
Dimensions and weight
MP 55A
Danfoss A/S, 10 - 2001
Technical leaflet - RD5CA302
Weight approx. 0.8 kg
27
Cartridge pressure control Type CC 20W Introduction
CC 20W pressure control series is designed to meet specific application requirements. Because of its small size, light weight, and environmental seal, it can be directly mounted at its pressure connection without the use of a mounting bracket. This reduces installation costs
and saves space. The pressure controls are available with a custom-designed pressure setting, electrical connection and pressure connection.
Features
• 6 A contact load • Small size and light weight suitable for direct mounting • Hermetically sealed sensor • Pressure ranges from vacuum to 50 bar • Bimetall connections make soldering easier • Enclosure IP 20 or IP 67
• • • •
Function
CC 20W contains one or more stainless steel diaphragms. Each diaphragm reverses its curvature when pressurized to a customerspecified value.
When the diaphragm snaps, electrical contacts open and close by means of a push rod. The pressure control resets automatically when pressure drops below a preset value.
Technical data Settings
CC 20W is supplied factory-set cut-in and cut-out values wihtin the range – 0,9 to 50 bar. The table below shows: - min. possible tolerance of cut-in and cut-out values.
- min. possible differential related to the highest factory set point - optimum differential band is used for economical optimisation of set points. Differential band = ratio low set point/high set point x100
Pressure
Factory setting bar
Custom-designed factory setting DIN 32733, UL and CSA approved Available with gold plated contacts LP controls are available with permissible working pressure of 35 bar Therefore no need for shut-off during pressure test.
Min. tolerance* bar
Min. differential* bar
Optimal differential band
Vakuum →1
± 0.2
0.35
1→2
± 0.2
0.7
40 → 65
2 → 5.5
± 0.4
1
45 → 70
LP
5.5 → 7 7 → 11 HP
50 → 70
± 0.5
2
50 → 75
± 0.5
2
60 → 75
11 → 16
± 0.7
3
60 → 75
16 → 24
± 0.7
4
60 → 75
24 → 31
± 0.7
5
65 → 80
31 → 50
±1
6
70 → 80
* Never select a smaller differential or a smaller tolerance than is practically necessary.
Electrical connections
SPST - NO LP protection
Danfoss A/S (RC-CM/hbs), 03 - 2002
Technical leaflet - RD5JB602
SPST - NC HP protection
SPST - NO Fan cycling
29
Cartridge pressure control, type CC 20W
Technical data
Vacuum → 50 bar
Range Reset
Automatic
Contact function
SPST-NO, SPST-NC
Electrical connection
Spade terminals (6.35 × 0.81 mm) or cables
Contact load
6 (6) 36 A/240 V a.c.
Pressure connections
1/4 in. female flare with valve opener 1/4 in. ODM solder 6 mm ODM solder 1/8-27 NPT 0.9 m capillary tube with 1/4 in. flare union nut 0.6 m capillary tube, OD = 2.4 mm 0.9 m capillary tube with 1/4 in. ODM solder
Max. working pressure PB
Vacuum → 7 bar, standard: 17 bar/spec.: 35 bar 7 → 36 bar: 41 bar 36 → 50 bar: 55 bar
Burst pressure
> 240 bar
Temperature of medium
– 55 → 135°C
Ambient temperature
– 30 → 65°C
Enclosrue
Cable version: IP 67 Spade version: IP 20
Approvals
-
1) 2)
Dimensions and weights
DWK refers to pressure controls that cut out on rising pressure. DWFK refers to pressure controls that cut out on falling pressure.
All dimensions in mm
Weight: 0.03 kg
30
DIN 32733: DWK 4B 048 941), DWFK 4B 049 942) UL Rec. File no. SA 995 (USA and Canada), USR category SDFY2, CSR category SDFY8 CEmarked acc. to VDE EN 60730-2-6
Weight: 0.05 kg
Technical leaflet - RD5JB602
Weight: 0.03 kg
Weight: 0.05 kg
Danfoss A/S (RC-CM/hbs), 03 - 2002
Cartridge pressure controls Type CC 25W Introduction
The CC 25W pressure control series is specially designed for applications where contact loads are high. CC 25W is available with changeover contacts, break contacts or make contacts. CC 25W has a stainless steel housing and diaphragm. This means that it can be used for almost all liquids and gases. With its compact form, CC 25W is the ideal choice where conditions are severe and space is limited. CC 25W can be used for fan control, and for high/low-pressure protection in air conditioning systems.
Features
• • • •
High contact load , 10 A for SPST Automatic reset Customer-specified factory setting Small size and light weight for direct mounting • DIN 32733, UL and CSA approved • Bi-metal solder connections
• IP 20 and IP 67 enclosure • SPDT and SPST available • SPST versions available with gold plated contacts • LP pressure controls are available with max. working pressure MWP = 35 bar for easy pressure testing
Function
The CC 25W contains one or more stainless steel diaphragms. Each diaphragm reverses its curvature when pressurized to a customer specified value.
When the diaphragm "snaps", electrical contacts open or close by means of a push rod. The pressure control resets automatically when pressure drops below a preset value.
Ordering
An overview of the product range can be obtained from Danfoss. Minimum order: 250-off
Technical data
Media
CFC, HCFC, HFC, oil
Range Reset Contact function Electrical connections Contact load
Vacuum → 50 bar Automatic SPST-NO, SPST-NC or SPDT Spade terminals (6.35 × 0.81 mm) or cable SPST 10 (10) 45 A/240 V a.c. SPDT-NO 5 (3) 17.5 A/240 V a.c. SPDT-NC 25 (10) 45 A/240 V a.c. 1 /4 in. female flare with valve opener 1 /4 in. ODM solder 6 mm ODM solder Vacuum → 7 bar, standard: 17 bar/spec. 35 bar 7 → 36 bar: 41 bar 36 → 50 bar: 55 bar > 240 bar – 55 → 135°C – 30 → 65° C Cable version: IP 67 Spade version:IP 20 - DIN 32733: DWK 4B 050 991), DWFK 4B 051 992) - UL Rec. File no. SA 995 (USA and Canada), USR category SDFY2, CSR category SDFY8 - CE marked acc. to VDE EN 60730-2-6
Pressure connections
Max. working pressure MWP
Burst pressure Media temperature Ambient temperature Enclosure Approvals
1) 2)
Danfoss A/S (RC-CM/hbs), 03 - 2002
DWK refers to pressure controls that cut out on rising pressure. DWFK refers to pressure controls that cut out on falling pressure.
Technical leaflet - RD5JC602
31
Cartridge pressure controls, type CC 25W
Technical data Setting
CC 25W is supplied factory set within the range -0.9 to 50 bar. The table below shows - Min. tolerances on make and break values. - Min. differential in relation to highest factory setting. Factory setting bar vacuum → 1 1→2 2 → 5.5 5.5 → 7 7 →11 11 →16 16 → 24 24 → 31 31 → 50
Pressure
LP
HP
- Optimum differential band for the most economical setting values. Differential band = ratio between lowest and highest setting x 100.
Min. tolerance*) bar ± 0.2 ± 0.2 ± 0.4 ± 0.5 ± 0.5 ± 0.7 ± 0.7 ± 0.7 ±1
Min. differential*) bar 0.35 0.7 1 2 2 3 4 5 6
Optimum differential band 25 → 45 30 → 60 45 → 70 50 → 75 60 → 75 60 → 75 60 → 75 65 → 80 70 → 80
*) Never select a smaller differential or a smaller tolerance than is practically necessary.
Electrical connections
SPDT LP- protection
SPST-NO Fan cycling
SPDT HP-protection
SPST-NC HP protection
SPST-NO Fan cycling
SPST-NO LP protection
Dimensions and weights All dimensions in mm
Weight: 0.06 kg
32
Weight: 0.05 kg
Technical leaflet - RD5JC602
Weight: 0.06 kg
Weight: 0.05 kg
Danfoss A/S (RC-CM/hbs), 03 - 2002
Cartridge pressure controls Type CC 29B Introduction
CC 29B pressure controls are high-pressure units with manual reset. The special snap mechanism in CC 29B pressure controls prevents activation of the contact system before the pressure has fallen to a safe level, even though the reset button has been pressed down. In CC 29B units the diaphragm and diaphragm element are made of stainless steel, which means long and problem-free operating life.
Features
• • • • • •
6 A contact load Manual reset IP 67 enclosure Solder connections in bimetal Long operating life Low installations costs
Function
The snap-acting bistable diaphragm used in the CC 29B pressure control opens the electrical contacts at a preset pressure.
Ordering
An overview of the product range can be obtained from Danfoss.
• • • •
Suitable for high-pressure refrigerants DIN 32733 (B), UL and CSA-approved Available with gold contacts Available with capillary tube connection for panel mounting • Flare or solder connection The contacts remain in this position until the reset button is activated.
Minimum order: 250-off
Technical data
Media:
CFC, HCFC, HFC, oil
Range
14 → 50 bar
Reset
Manual
Contact function
SPST-NC
Electrical connections
Cable
Contact load
6 (6) 36 A/240 V a.c.
Pressure connections
1
/4 in. female flare with valve opener /4 in. ODM solder 6 mm ODM solder 0.9 m cap. tube with 1/4 in. flare union nut 0.6 m cap. tube, dia. 2.4 mm 0.9 m cap. tube with 1/4 in. ODM solder 1
Danfoss A/S (RC-CM/hbs), 03 - 2002
Max. working pressure MWP
14 → 35 bar: 41 bar 36 → 50 bar: 55 bar
Burst pressure
> 240 bar
Media temperature
– 55 →135°C
Ambient temperature
– 30 → 65°C
Enclosure
IP 67
Approvals
- DIN 32733: DBK 4B 052 99 - UL Rec. File no. SA 995 (USA and Canada), USR category SDFY2, CSR category SDFY8 - CE marked acc. to VDE EN 60730-2-6
Technical leaflet - RD5JD602
33
Cartridge pressure controls, type CC 29B
The CC 29B is supplied with factory-set cutout within the range 14 to 50 bar.
Technical data Setting
The table shows: - minimum possible tolerance of cut-out set point. - minimum possible differential when presetting the control.
Factory setting bar
Min. tolerance* bar
Min. differential* bar
14 → 16
± 0.7
3
16 → 24
± 0.7
4
24 → 31
± 0.7
5
31 → 50
±1
6
* Never select a smaller differential or a smaller tolerance than is practically necessary.
Electrical connections
SPST-NC HP protection, man. reset
Dimensions and weights All dimensions in mm
Dia. 2.4 mm copper capillary tube
Weight: 0.1 kg
34
Weight: 0.1 kg
Technical leaflet - RD5JD602
Weight: 0.1 kg
Danfoss A/S (RC-CM/hbs), 03 - 2002
Cartridge pressure controls Type CC 80W Introduction
CC 80W is a little cartridge pressure control for use in refrigeration and A/C systems. CC 80W is equipped with a 6 amp switch and automatic reset. The control is robust and reliable in operation in many types of units. The small size, lightness and high degree of enclosure of the unit mean that it can be mounted direct on refrigeration systems where pressure regulation is required. The control is available with pressure setting and pressure connection to suit customers’ requirements. All these features reduce installation costs and save space.
Application
To be used in refrigeration and A/C systems with CFC, HCFC and HFC.
High and low pressure safety cut out or fan cycling.
Features
• 6 A contact load • Small size and light weight suitable for direct mounting • Hermetically sealed sensor • Pressure ranges from 0 to 50 bar • Bimetal connections make soldering easier • Enclosure IP 20 or IP 67
• Corrosion resistant package • Tamper-proof, factory preset setpoints • DIN 32733, UL approved in the USA and Canada • LP controls are available with max. working pressure of 35 bar. HP controls to 55 bar. • Excellent setpoint repeatability and stability
Function
CC 80W contains one or more stainless steel diaphragms. Each diaphragm reverses its curvature when pressurized to a customer specified value.
When the diaphragm "snaps", electrical contacts open and close by means of a push rod. The pressure control resets automatically when pressure drops below a preset value.
Ordering
An overview of the product range for use when ordering is obtainable from Danfoss.
Minimum order: 100-off
Technical data
1) 2)
Danfoss A/S (RC-CM/hbs), 03 - 2002
Media
CFC, HCFC, HFC, oil
Range
0 → 50 bar (e)
Reset
Automatic
Contact function
SPST-NO, SPST-NC
Electrical connection
Spade terminals (6.35 × 0.81 mm) or cross-linked polyethylene cables
Contact load
6 (6) 36 A/240 V a.c.
Pressure connections
1 /4 in. ODM solder 6 mm ODM solder 1 /4 in. female flare with valve opener
Max. working pressure PB (MWP)
0 → 7 bar (e), standard: 17 bar/spec.: 35 bar 7 → 36 bar: 41 bar 36 → 50 bar: 55 bar
Burst pressure
> 240 bar
Temperature of medium
– 55 → 135°C
Ambient temperature
– 30 → 65°C
Enclosure
Cable version: IP 67 Spade version: IP 20
Approvals
- DIN 32733: DWK 4B 090 971), DWFK 4B 091 992) - UL Rec. File no. SA 995 (USA and Canada), USR category SDFY2, CSR category SDFY8 - CE-marked acc. to VDE EN 60730-2-6
DWK refers to pressure controls that cut out on rising pressure. DWFK refers to pressure controls that cut out on falling pressure.
Technical leaflet - RD5JG202
35
Cartridge pressure controls, type CC 80W
Technical data Settings
CC 80W is supplied with factory preset cut-in and cut-out values wihtin the range 0 to 50 bar. The table below guides you to an optimum selection and shows: - min. possible tolerance of cut-in and cut-out setpoints - min. possible differential related to the highest factory set point
Pressure
LP
Factory setting bar 0 →1 1→2
HP
- optimum differential band is used for economical optimisation of set points. Differential band =
Min. tolerance* bar ± 0.2 ± 0.2
2 → 5.5 5.5 → 7 7 → 11 11 → 16 16 → 24 24 → 31 31 → 50
± 0.4 ± 0.5 ± 0.5 ± 0.7 ± 0.7 ± 0.7 ±1
Low setpoint x 100 High setpoint
Min. differential* bar 0.35 0.7
Optimal differential band 25 → 45 30 → 60
1 2 2 3 4 5 6
45 → 70 50 → 75 60 → 75 60 → 75 60 → 75 65 → 80 70 → 80
* Never select a smaller differential or a smaller tolerance than is practically necessary.
Electrical connections
Dimensions and weights
All dimensions in mm
Weight: 0.03 kg
36
Weight: 0.05 kg
Technical leaflet - RD5JG202
Weight: 0.03 kg
Weight: 0.05 kg
Danfoss A/S (RC-CM/hbs), 03 - 2002
Thermostats Type KP Introduction
KP thermostats are single-pole, double-throw (SPDT) temperature-operated electric switches. A KP thermostat can be connected directly to a single-phase alternating current motor of up to approx. 2 kW or installed in the control circuit of direct current motors and large alternating current motors. KP thermostats are used for regulation, but can also be seen in safety monitoring systems. It is here that the electronic mechanism shows its superiority. KP thermostats are available with vapour charge or with adsorption charge. With vapour charge the differential is very small. KP thermostats with adsorption charge are widely used to give frost protection.
Features
• Wide regulating range • Can be used for deep freeze, refrigeration and air conditioning plant • Welded bellows elements mean increased reliability • Small dimensions Easy to install in refrigerated counters or cold rooms. • Ultra-short bounce times This gives long operating life, reduces wear to a minimum and increases reliability.
Approvals
CE-marked in accordance with EN 60947-4/-5 for sale in Europe.
• Standard versions with changeover switch Possible to obtain opposite contact function or to connect a signal. • Electrical connection at the front of the unit Facilitates rack mounting. Saves space. • Suitable for alternating and direct current • Cable entry of soft thermoplastic for cables from 6 to 14 mm diameter. • Extensive and wide range
RINA, Registro Italiano Navale, Italy BV, France
F Germanischer Lloyd, Germany LR, UK P Polski Rejestr Statków, Poland MRS, Maritime Register of Shipping, Russia DnV, Det norske Veritas, Norway C
Danfoss A/S, 05 - 2002
S UL approval for USA and Canada
Technical leaflet - RD5DC302
37
Thermostats, type KP
Regulating range KP 61 Vapour range KP 62 KP 63 KP 68 KP 69
Adsorption charge
KP 62 KP 71 KP 73 KP 75 KP 77 KP 79 KP 81
KP 98 HT KP 98 OIL
KP 98 OIL KP 98 HT
−50
Technical data
0
+50
+100
Ambient temperature −40 → +65°C (+80°C for max. 2 hours). Switch Single-pole, double-throw (SPDT) changeover switch. Contact load Alternating current: AC1: 16 A, 400 V AC3: 16 A, 400 V AC15: 10 A, 400 V Max. starting current (L.R.): 112 A, 400 V Direct current: DC13: 12 W, 220 V control current
+150
+200°C
Cable connection Cable entry for cables 6 → 14 mm dia. A Pg 13.5 screwed cable entry can be used for 6 → 14 mm dia. cables. With 8 → 16 mm cables a standard Pg 16 screwed cable entry can be used. Enclosure IP 30 to IEC 529 This grade of enclosure is obtained when the unit is mounted on a flat surface or bracket. The bracket must be fixed so that all unused holes are covered.
Properties according to EN 60947: Wire dimensions solid/stranded 0.75 - 2.5 mm2 flexible, w/out ferrules 0.7 - 2.5 mm2 flexible, with ferrules 0.5 - 1.5 mm2 Tightning torque max. 2 NM Rated impulse voltage 4 kV Pollution degree 3 Short circuit protection, fuse 10 Amp Insulation 400 V IP 30/44
38
Technical leaflet - RD5DC302
Danfoss A/S, 05 - 2002
Thermostats, type KP
Contact systems
KP thermostats
Ordering
Charge
Bulb
Setting
Differential ∆t
type
range
Lowest Highest temperature temperature °C °C
KP 61
A
– 30 → 15
5.5 → 23
1.5 → 7
Aut.
120
2
060L1100
KP 61
A
– 30 → 15
5.5 → 23
1.5 → 7
Aut.
120
5
060L1101
KP 61
B
– 30 → 13
4.5 → 23
1.2 → 7
Aut.
120
2
060L1102
KP 61
B
– 30 → 15
5.5 → 23
1.5 → 7
Aut.
120
2
060L1103 3)
KP 61
B
– 30 → 15
5.5 → 23
1.5 → 7
Aut.
120
2
060L1128 3) 4)
KP 61
A
– 30 → 15
Fixed 6
Fixed 2
Min.
120
5
060L1104
KP 61
B
– 30 → 15
Fixed 6
Fixed 2
min.
120
2
060L1105
KP 62
C1
– 30 → 15
6.0 → 23
1.5 → 7
Aut.
120
KP 63
A
– 50 → – 10
10.0 → 70
2.7 → 8
Aut.
120
2
060L1107
KP 63
B
– 50 → – 10
10.0 → 70
2.7 → 8
Aut.
120
2
060L1108
KP 68
C1
– 5 → 35
4.5 → 25
1.8 → 7
Aut.
120
KP 69
B
– 5 → 35
4.5 → 25
1.8 → 7
Aut.
120
KP 62
C2
– 30 → 15
5.0 → 20
2.0 → 8
Aut.
80
KP 71
E2
– 5 → 20
3.0 → 10
2.2 → 9
Aut.
80
2
060L1113
KP 71
E2
– 5 → 20
Fixed 3
Fixed 3
min.
80
2
060L1115
KP 73
E1
– 25 → 15
12.0 → 70
8.0 → 25
Aut.
80
2
060L1117
KP 73
D1
– 25 → 15
4.0 → 10
3.5 → 9
Aut.
80
2
060L1118 3)
KP 73
D1
– 25 → 15
Fixed 3.5
Fixed 3.5
min.
80
2
060L1138
KP 73
D2
– 20 → 15
4.0 → 15
2.0 → 13
Aut.
55
3
060L1140
KP 73
D1
– 30 → 15
3.5 → 20
3.25 → 18
Aut.
80
2
060L1143
Type
°C
Vapour 1)
Adsorbtion 2)
KP 98
Reset
Max. Capillarybulb temp. °C
Code no.
tube length m
060L1106
060L1111 2
060L1112 060L1110 3) 4)
KP 75
F
0 → 35
3.5 → 16
2.5 → 12
Aut.
110
2
060L1120
KP 75
E2
0 → 35
3.5 → 16
2.5 → 12
Aut.
110
2
060L1137
KP 77
E3
20 → 60
3.5 → 10
3.5 → 10
Aut.
130
2
060L1121
KP 77
E3
20 → 60
3.5 → 10
3.5 → 10
Aut.
130
3
060L1122
KP 77
E2
20 → 60
3.5 → 10
3.5 → 10
Aut.
130
5
060L1168
KP 79
E3
50 → 100
5.0 → 15
5.0 → 15
Aut.
150
2
060L1126
KP 81
E3
80 → 150
7.0 → 20
7.0 → 20
Aut.
200
2
060L1125
KP 81
E3
80 → 150
Fixed 8
Fixed 8
Max.
200
2
060L1155
KP 98
E2
OIL: 60 → 120
OIL: Fixed 14 OIL: Fixed 14
Max.
150
1
E2
HT: 100 → 180
HT: Fixed 25 HT: Fixed 25
Max.
250
2
060L1131
1)
Bulb must always be placed colder than the thermostat housing and capillary tube. The thermostat will then regulate independent of ambient temperature. Bulb can be placed warmer or colder than thermostat housing and capillary tube, but variations from +20°C ambient temperature will influence the scale accuracy. 3) With manual switch, not isolating switch. 4) Panel mounting model with top plate. 2)
Danfoss A/S, 05 - 2002
Technical leaflet - RD5DC302
39
Thermostats, type KP
Ordering (continued)
40
Thermostat bulb types
A
Straight capillary tube
B
∅ 9.5 × 70 mm remote air coil
C
C1: ∅ 40 × 30 mm air coil C2: ∅ 25 × 67 mm air coil (integral with thermostat)
D
D1: ∅ 10 × 85 mm double contact remote bulb D2: ∅ 16 × 170 mm double contact remote bulb Note! Cannot be used in sensor (bulb) pocket
E
E1: ∅ 6.4 × 95 mm remote bulb E2: ∅ 9.5 × 115 mm remote bulb E3: ∅ 9.5 × 85 mm remote bulb
F
∅ 25 × 125 mm remote duct coil
Technical leaflet - RD5DC302
Danfoss A/S, 05 - 2002
Thermostats, type KP
Design Function
Vapour charge Key sketch of KP thermostats
1. 2. 3. 7. 8. 9. 12. 13. 14. 15. 16. 17.
Temperature setting spindle Differential setting spindle Main arm Main spring Differential spring Bellows Switch Terminals Earth terminal Cable entry Tumbler Sensor
Adsorption charge
Adsorption charge
Vapour charge
The switch in the KP has a snap-action function and the bellows move only when the cut-in or cut-out value is reached.
Danfoss A/S, 05 - 2002
Technical leaflet - RD5DC302
The design of the KP thermostat affords the following advantages: − high contact load − ultra-short bounce time − vibration resistance up to 4 g in the range 0-1000 Hz − long mechanical and electrical life.
41
Thermostats, type KP
Design Function (continued)
1. Temperature setting spindle, OIL 3. Main arm 5. Temperature setting spindle, HT 7. Main spring 9. Bellows 10. Capillary tube, OIL 11. Capillary tube, HT 12. Switch 13. Terminals 14. Earth terminal 15. Cable entry 16. Tumbler 17. Sensor (bulb) 18. Locking plate
Terminology
KP 98, dual thermostat
Dual thermostat KP 98 is used to provide protection against excessively high discharge gas temperature and to ensure a suitable oil temperature in the compressor. To avoid the temperature of the hot gas exceeding the maximum permissible value during extreme operating conditions (low evaporating pressure, high condensing pressure, high suction vapour superheat) a KP 98 thermostat can be used on the high temperature side (HT). If the temperature of the hot gas becomes too high the refrigerant will break down and the compressor discharge valve will become damaged.
The risk is greatest in refrigeration systems that operate on a high compression ratio (e.g. in systems with NH3 or R 22) and in applications with hot gas bypass. This unit has two separate thermostat functions. The HT sensor that controls the discharge gas temperature is fitted on the discharge tube immediately after the compressor. For larger compressors, the sensor can be built into the discharge line. The OIL sensor that controls the oil temperature is located in the compressor oil sump.
Differential The differential is the difference between the make and break temperatures. A differential is necessary for satisfactory automatic operation of the plant.
Reset 1. Manual reset: Units with manual reset can only be restarted after the reset button has been activated. On min. reset units the set value is equal to the cut-out value for falling temperature. On max. reset units the set value is equal to the cut-out value for rising temperature.
Mechanical differential (intrinsic differential) The mechanical differential is the differential set by the differential spindle. Operating differential (thermal differential) The operating differential is the differential the plant operates on. Operating differential is the sum of the mechanical differential and the differential produced by the time constant.
42
Technical leaflet - RD5DC302
2. Automatic reset: These units are automatically reset after operational stop.
Danfoss A/S, 05 - 2002
Thermostats, type KP
Setting
Charges
Thermostats with automatic reset Set the upper activating temperature on the range scale. Set the differential on the "DIFF" scale. The temperature setting on the range scale will then correspond to the temperature at which the refrigeration compressor will be started on rising temperature. The compressor will be stopped when the temperature has fallen in relation to the differential setting. Note that the differential depends on the range setting. Therefore, the differential scale must only be used as guideline. If with low stop temperature settings the compressor will not stop, check whether the differential is set at too high a value!
Thermostats with minimum reset Set the stop temperature on the range scale. The differential is a fixed setting. The compressor can be restarted by pressing the "Reset button" after the temperature on the thermostat sensor has risen by a value equal to the fixed differential setting. Thermostats with maximum reset Set the stop temperature on the range scale. The differential is a fixed setting. The compressor can be restarted by pressing the "Reset button" after the temperature on the thermostat sensor has fallen to a value equal to the fixed differential setting.
1. Vapour charge
9. Bellows element 17. Sensor (bulb) 19. Capillary tube
Here the interdependence between the pressure and temperature of saturated vapour is utilized, i.e. the element is charged with saturated vapour plus a small amount of liquid. The charge is pressure-limited; a further increase in pressure after evaporation of all the liquid in the sensor (17) will only result in a small pressure increase in the element.
This principle can be utilized in thermostats for low temperature, etc. where evaporation must be able to take place from the free liquid surface in the sensor (within the operating range of the thermostat), and where at the same time, the bellows must be protected against deformation when kept at normal ambient temperatures. Since the pressure in the element depends on the temperature at the free liquid surface, the thermostat must always be placed so that the sensor is colder than the rest of the thermostatic element. The evaporated liquid will recondense at the coldest point, i.e. the sensor. Thus, as intended, the sensor becomes the temperature-controlling part of the system. Note: When the sensor is coldest, the ambient temperature has no effect on regulating accuracy.
2. Adsorption charge In this case the charge consists partly of a superheated gas and partly of a solid having a large adsorption surface. The solid is concentrated in the sensor (17) and it is therefore always the sensor that is the temperature-controlling part of the thermostatic element. The sensor can be placed warmer or colder than thermostat housing and capillary tube, but variations from +20°C ambient temperature will influence the scale accuracy.
9. Bellows element 17. Sensor (bulb) 19. Capillary tube
Danfoss A/S, 05 - 2002
Technical leaflet - RD5DC302
43
Thermostats, type KP
Dimensions and weights Weight KP 61-81: approx. 0.4 kg KP 98: approx. 0.6 kg
KP 61-81
Mounting holes (back of KP)
Mounting holes (back of KP)
KP 98
Wall bracket
A: KP 61, KP 63
44
B: KP 61, KP 63, KP 69
C1: KP 62, KP 68
C2: KP 62
Angle bracket
D2: KP 73
Technical leaflet - RD5DC302
E2: KP 71 KP 73 KP 75 KP 77 KP 98
E3: KP 77 KP 79 KP 81
D1: KP 73
E1: KP 73
F: KP 75
Danfoss A/S, 05 - 2002
Thermostats, differential thermostats Type RT Introduction
An RT thermostat is fitted with a single-pole changeover switch. The position of the contacts depends on the bulb temperature and the set scale value. The RT series includes thermostats for general applications within industrial and marine refrigeration. The RT series also includes differential thermostats, thermostats for neutral zone regulation, and special thermostats with gold-plated contact surface for PLC applications.
Features
Technical data
• Waterproof versions, enclosure IP 66
• Suitable for alternating and direct current
• Wide regulating range
• Interchangeable contact system
• Wide range of units for industrial and marine applications
• Special versions for PLC applications
Cable connection Pg 13.5. Cable diameter 6 → 14 mm.
Permissible ambient temperature −50 → +70°C for thermostat housing.
Enclosure IP 66 to IEC 529, except for versions with ext. reset which are to IP 54.
Switches See "Ordering switches".
Properties according to EN 60947: Wire dimensions solid/stranded flexible, w/out ferrules flexible, with ferrules Tightening torque Rated impulse voltage Pollution degree Short circuit protection, fuse Insulation IP
Danfoss A/S, 05 - 2002
Technical leaflet - RD5EA302
0.2 - 2.5 mm2 0.2 - 2.5 mm2 0.2 - 1.5 mm2 max. 1.5 NM 4 kV 3 10 Amp 400 V 30/44
45
Thermostats, differential thermostats, type RT
RT 8
RT 8L
RT 9
RT 10
RT 11
RT 12
RT 13
RT 14
RT 14L
RT 15
RT 16L
RT 17
RT 23
RT 24
RT 34
RT 101
RT 102
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
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RT 270
RT 7
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RT 140L
RT 4
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RT 140
RT 3
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RT 107
RT 2
Approvals
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P Polski Rejestr Statków, Poland •
RINA, Registro Italiano Navale, Italy
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CE mark according to RN 60947-4, -5
1)
Special versions supplied from Danfoss, Canada.
Overview −50
0
+50
+100
+150
+200
+250
+300°C
Vapour-charged with remote bulb (bulb coldest)
Adsorption-charged with remote bulb (bulb warmest or coldest)
Partial charge with remote bulb (bulb warmest)
Range °C −60 → -25
RT 10
−45 → −15
RT 9
−30 → 0
RT 13
−25 → +15
RT 3
−25 → +15
RT 2, 7
−20 → +12
RT 8
−5 → +10
RT 12
−5 → +30
RT 14
+5 → +22
RT 23
+8 → +32
RT 15
+15 → +34
RT 24
+15 → +45
RT 140
+25 → +90
RT 101, 102
+70 → +150 RT 107 −50 → −15
Vapour-charged with coiled capillary tube sensor (room thermostats)
−5 → +30
RT 4
Adsorption-charged with coiled capillary tube sensor (room thermostats)
−25 → +15
RT 34
Adsorption-charged differential thermostats with remote bulb (bulb warmest or coldest)
46
+50
+100
+150
Technical leaflet - RD5EA302
+200
+250
RT 11
−20 → +12
RT 8L
−5 → +30
RT 14L
+15 → +45
Vapour-charged dead zone thermostat (room thermostat)
0
RT 17
−30 → 0
Adsorption-charged dead zone thermostats with remote bulb (bulb warmest or coldest)
−50
Type
RT 140L
0 → +38
RT 16L
−30 → +40
RT 270
+300°C
Danfoss A/S, 05 - 2002
Thermostats, differential thermostats, type RT
Ordering
Thermostats Differential ∆ t Lowest Highest temp. temp. setting setting K K
Reset
Max. bulb temp.
Capillary tube length
°C
m
1.0→ 3.0
Aut.
150
2
017-5077
2.2→10.0
1.0→ 4.5
Aut.
150
2
017-5066
−25 → +15
2.8→10.0
1.0→ 4.0
Aut.
150
2
017-5014
B
−50 → −15
2.2→ 7.0
1.5→ 5.0
Aut.
100
017-5117
RT 11
B
−30 → 0
1.5→ 6.0
1.0→ 3.0
Aut.
66
017-5083
RT 4
B
1.5→ 7.0
1.2→ 4.0
Aut.
75
017-5036 017-50374)
Regulation range
Charge
Type
Bulb type
Vapour 1)
RT 10
A
−60 → −25
1.7→ 7.0
RT 9
A
−45 → −15
RT 3
A
RT 17
°C
−5 → +30
Code no.
RT 13
A
−30 → 0
1.5→ 6.0
1.0→ 3.0
Aut.
150
2
Adsorp-
RT 2
A
−25 → +15
5.0→18.0
6.0→20.0
Aut.
150
2
017-5008
tion 2)
RT 8
A
−20 → +12
1.5→ 7.0
1.5→ 7.0
Aut.
145
2
017-5063
RT 12
A
−5 → +10
1.0→ 3.5
1.0→ 3.0
Aut.
65
2
017-5089
RT 23
A
+5 → +22
1.1→ 3.5
1.0→ 3.0
Aut.
85
2
017-5278
RT 15
A
+8 → +32
1.6→ 8.0
1.6→ 8.0
Aut.
150
2
017-5115
RT 24
A
+15 → +34
1.4→ 4.0
1.4→ 3.5
Aut.
105
2
017-5285
RT 140
C
+15 → +45
1.8→ 8.0
2.5→11.0
Aut.
240
2
017-5236
RT 102
D
+25 → +90
2.4→10.0
3.5→20.0
Aut.
300
2
017-5147
RT 34
B
−25 → +15
2.0→10.0
2.0→12.0
Aut.
100
RT 7
A
−25 → +15
2.0→10.0
2.5→14.0
Aut.
150
2
017-5053
RT 14
A
−5 → +30
2.0→ 8.0
2.0→10.0
Aut.
150
2
017-5099
Partial 3)
017-5097
017-5118
RT 101
A
+25 → +90
2.4→10.0
3.5→20.0
Aut.
300
2
017-5003
RT 107
A
+70 → +150
6.0→25.0
1.8→ 8.0
Aut.
215
2
017-5135
1) The sensor must be located colder than thermostat housing and capillary tube. 2) The sensor can be located warmer or colder than thermostat housing. 3) The sensor must be located warmer than thermostat housing and capillary tube. 4) With built-in heating coil − reduces the thermal differential.
Thermostats with adjustable dead zone Max. bulb temp.
Capillary tube length
K 1.5 / 0.7
Dead zone NZ Lowest Highest temp. temp. setting setting K K 1.5 → 5.0 0.7 → 1.9
°C
m
Regulation range
Differential
°C
Charge
Type
Bulb type
Vapour
RT 16L
B
0 → +38
Adsorption
RT 8L
A
−20 → +12
1.5
1.5 → 4.4 1.5 → 4.9
145
2
RT 14L
A
−5 → +30
1.5
1.5 → 5.0 1.5 → 5.0
150
2
017L0034
RT 140L
C
+15 → +45
1.8 / 2.0
1.8 → 4.5 2.0 → 5.0
240
2
017L0031
RT 101L
A
+25 → +90
2.5 / 3.5
2.5 → 7.0 3.5 → 12.5
300
2
017L0062
100
Code no.
017L0024 017L0030
Type of bulb / sensor A
Cylindrical remote sensor
B
Room sensor
Special versions RT can be supplied with special switches. See next page.
Danfoss A/S, 05 - 2002
Technical leaflet - RD5EA302
C
D
Duct sensor
Capillary tube sensor
When ordering, please state 1. Type 2. Code no. of standard unit 3. Code no. of special switch
47
Thermostats, differential thermostats, type RT
Ordering (continued)
Switches Version
Symbol
Description
SPDT
Single-pole changeover switch with terminal board proof against leakage current. Fitted in all standard versions of type RT. Snap action changeover contacts.
Standard
Man. reset SPDT Man. reset
Contact rating
For manual reset of unit after contact changeover on rising temperature. For units with reset facility.
Alternating current Ohmic: AC1 = 10 A, 400 V Inductive: AC3 = 4 A, 400 V AC15 = 3 A, 400 V Dir. current: DC13 = 12 W, 220 V
For manual reset of unit after contact changeover on falling temperature. For units with reset facility.
Reset
Code no.
Aut.
017-4030
Max.
017-4042
Min.
017-4041
SPDT Dead zone
Single-pole changeover switch with dead zone and terminal board proof against leakage current.
Available only as a component part of RT controls with adjustable dead zone
SPDT
Standard
SPDT Man. reset
SPDT
Single-pole changeover switch with gold plated (oxide-free) contact surfaces. Increases cut-in reliability on alarm and monitoring systems, etc. Snap action changeover contacts. Terminal board proof against leakage current.
SPDT
Single-pole changeover switch with dead zone and gold plated (oxide-free) contact surfaces. Increase cut-in reliability on alarm and monitoring systems, etc. Snap action changeover contacts. Terminal board proof against leakage current.
SPDT
Single-pole changeover switch with gold plated (oxide-free) contact surfaces. Increases cut-in reliability on alarm and monitoring systems, etc. Snap action changeover contacts. Terminal board proof against leakage current.
SPST
Single-pole changeover switch that cuts in two circuits simultaneously on rising temperature. Snap action changeover contacts. Terminal board proof against leakage current.
SPST
Single-pole changeover switch that cuts out two circuits simultaneously on rising temperature. Snap action changeover contacts. Terminal board proof against leakage current.
Dead zone
Man. reset
Cuts in two circuits simultaneously
Cuts out two circuits simultaneously
With non-snap action changeover contacts 1)
Single-pole changeover switch with gold plated (oxide-free) contact surfaces. Increases cut-in reliability on alarm and monitoring systems, etc. Snap action changeover contacts. Terminal board proof against leakage current.
Single-pole changeover switch with non-snap action changeover contacts.
Alternating current Ohmic: AC1 = 10 A, 400 V Inductive: AC3 = 2 A, 400 V AC15 = 1 A, 400 V Dir. current: DC13 = 12 W, 220 V
Aut.
017-4240
Max.
017-4048
Available only as a component part of RT controls with adjustable dead zone
Alternating current Ohmic: AC1 = 10 A, 400 V Inductive: AC3 = 3 A, 400 V AC15 = 2 A, 400 V Dir. current: DC13 = 12 W, 220 V 1)
Alternating or direct current 25 VA, 24 V
Min.
017-4047
Max.
017-4034
Min.
017-4036
017-0181
SPDT
If current is led through contacts 2 and 4, i.e. terminals 2 and 4 connected but not 1, max. permissible load is increased to 90 W, 220 V.
The switches are shown in the position they assume on falling temperature, i.e. after downward movement of the RT main spindle. The setting pointer of the control shows the scale value at which contact changeover occurs on falling temperature.
An exception is RT with switch, code no. 017-4042, with max. reset where the setting pointer shows the scale value at which contact changeover occurs on rising temperature.
Spare parts and accessories, see spare parts catalogue RK0XG.
48
Technical leaflet - RD5EA302
Danfoss A/S, 05 - 2002
Thermostats, differential thermostats, type RT
Design Function
5. Setting knob 9. Regulation range scale 10. Loop terminal 11. Pg 13.5 screwed cable entry 12. Main spring 14. Terminals 15. Main spindle 16. Switch 17. Upper guide bush 18. Contact arm 19. Differential temperature setting nut 23. Bellows element 25. Fixing hole 26. Sensor (bulb) clip 28. Capillary tube 29. Sensor (bulb) 30. Sensor (bulb) pocket 31. Capillary tube gland 38. Earth terminal 44. Temperature setting spindle
Thermostat type RT
Key sketch of RT thermostat
RT thermostat
The thermostatic element consists of a sensor (29) capillary tube (28) and bellows element (23). The element contains a charge that reacts to temperature variations at the sensor so that the pressure on the moving bellows rises when temperature rises. By turning the setting knob (5) the main spring (12) can be set to balance the pressure in the element.
Danfoss A/S, 05 - 2002
Technical leaflet - RD5EA302
A rise in temperature at the sensor compresses the bellows and moves the main spindle (15) upwards until spring force and element pressure are in equilibrium. The main spindle (15) is fitted with a guide bush (17) and a differential setting nut (19) that together transfer the main spindle movement to the switch (16).
49
Thermostats, differential thermostats, type RT
Design Function (continued)
5. Setting knob 9. Regulation range scale 12. Main spring 15. Main spindle 16. Switch 17. Upper guide bush 18a and 18b. Contact arm 20. Lower guide bush 23. Bellows element 25. Fixing hole 28. Capillary tube 29. Sensor (bulb) 40. Neutral zone setting nut 44. Temperature setting spindle
Terminology
50
Thermostats with neutral zone, type RT L
RT L thermostat
Key sketch RT L thermostat
RT L pressure controls are fitted with a switch (17-4032) with an adjustable neutral zone. This enables the units to be used for floating control. The neutral zone switch contact arms (18a) and (18b) are operated by the spindle guide bushes (17) and (20). The upper guide bush (17) is fixed
while the lower guide bush (20) can be moved up or down by the setting nut (40). In this way the neutral zone can be varied between a minimum value (equal to the mechanical differential of the unit) and a maximum value (depending on the type of RT unit).
Floating control A form of delayed control where the correcting element (e.g. valve, damper, or similar) moves towards one extreme position at a rate independent of the magnitude of the error when the error exceeds a definite positive value, and towards the opposite extreme position when the error exceeds a definite negative value.
Hunting Periodic variations of the controlled variable from the fixed reference.
Technical leaflet - RD5EA302
Neutral zone The interval between the make points of the two contacts.
Danfoss A/S, 05 - 2002
Thermostats, differential thermostats, type RT
Charges
1. Vapour charge This principle can be utilized in thermostats for low temperature, etc., where evaporation must be able to take place from the free liquid surface in the bulb (within the operation range of the thermostat), and where at the same time, the bellows must be protected against deformation when kept at normal ambient temperatures. Since the pressure in the element depends on the temperature at the free liquid surface, the thermostat must always be placed so that the bulb is colder than the rest of the thermostatic element. The evaporated liquid will recondense at the coldest point, i.e. the bulb. Thus, as intended, the bulb becomes the temperature-controlling element in the system. Here the interdependence between the pressure and temperature of saturated vapour is utilized, i.e. the element is charged with saturated vapour plus a small amount of liquid. The charge is pressure-limited; a further increase in pressure after evaporation of all the liquid in the bulb, will only result in a small pressure increase in the element.
Note: When the bulb is coldest, the ambient temperature has no effect on regulating accuracy.
2. Adsorption charge Scale deviation factor
Relative scale setting (%)
In this case the charge consists partly of a superheated gas and partly of a solid having a large adsorption surface. The solid is concentrated in the bulb and it is therefore always the bulb that is the temperature-controlling part of the thermostatic element. The bulb can thus be placed warmer or colder than the rest of the thermostatic element. Such a charge is however to some extent sensitive to changes in the temperature of the bellows element and capillary tube. Under normal conditions this is not important, but if the thermostat is used in extreme conditions, scale deviation will occur. The scale can be corrected by using the graph and the table. Scale correction = Z × a. Z can be found in the graph and "a" in the table.
Danfoss A/S, 05 - 2002
Technical leaflet - RD5EA302
Curves for different ambient temperatures. 0% ~ lowest scale setting temperature, 100% ~ highest scale setting temperature.
Type
Regulating range °C
Correction factor a
RT 2 RT 7 RT 8, RT 8L RT 12 RT 14, RT 14L RT 15 RT 23 RT 24 RT 101, RT 102 RT 140, RT 140L
−25 → +15°C −25 → +15°C −20 → +12°C −5 → +10°C −5 → +30°C +8 → +32°C +5 → +22°C +15 → +34°C +25 → +90°C +15 → +45°C
2.3 2.9 1.7 1.2 2.4 1.2 0.6 0.8 5.0 3.1
51
Thermostats, differential thermostats, type RT
Charges (continued)
Example Scale correction on an RT 14 (range −5 to +30°C) at activating temperature +12°C and ambient temperature −10°C. The scale temperature, +12°C, lies approximately in the middle of the scale range, i.e. relative scale setting of 50%. The factor Z can be found in the graph from 50% and the curve for −10°C, i.e. approx. −1.2.
The correction factor "a" can be found in the table for an RT 14, i.e. 2.4. The scale correction = Z × a = −1.2 × 2.4 = −2.88. If activation at +12°C for the same conditions is required, the thermostat must be set at +12 × 2.88 = 9.12 ≈ 9.1.
3. Partial charge As with the vapour charge, the partial charge utilizes the interdependence between the pressure and temperature of saturated vapour. The partial charge is of such a volume that the bellows housing, capillary tube and a small part of the bulb are filled when the thermostat is in operation. The bulb is thus the warmest part of the system. The liquid will condense in the remaining, coldest, part of the system but because of the volume of the charge the free liquid surface will always be in the bulb. In this way, the bulb becomes the temperature-controlling part of the system.
Partial charge is used in RT units having a range lying higher than ambient temperature.
52
Technical leaflet - RD5EA302
Note: When the bulb is placed warmest, the ambient temperature has no effect on regulating accuracy.
Danfoss A/S, 05 - 2002
Thermostats, differential thermostats, type RT
Design Function
RT differential thermostat
An RT differential thermostat contains a singlepole changeover switch that makes or breaks depending on the temperature difference between the two sensors of the unit. The RT 270 is for use in process plant, ventilation plant, and refrigeration and heating plant where there is need to maintain a certain temperature differential, 0 - 15°C, between two media. One sensor is used as a reference and the other as a control sensor. The temperature differential is the direct controlled variable. The figure shows a cross-section of the RT 270. The differential thermostat contains two bellows elements: the LT element whose sensor must be placed in the medium having the lowest temperature, and the HT element whose sensor must be placed in the medium having the highest temperature. The main spring has a rectilinear characteristic. Within the operating range the RT 270 can be set for different temperature differentials by the setting disc (5).
1. LT sensor (bulb) 2. Capillary tube 4. LT bellows element 5. Setting disc 9. Regulation range scale 10. Loop terminal 11. Pg 13.5 screwed cable entry 12. Main spring 14. Terminals 15. Main spindle 16. Switch 17. Upper guide bush 18. Contact arm 20. Lower guide bush 24. HT bellows element 25. Fixing hole 28. Capillary tube 32. HT sensor (bulb) 38. Earth terminal 39. Blow-out disc
Terminology
When the differential between LT and HT sensor temperature falls, the main spindle (15) moves downwards. The contact arm (18) is moved downwards by the guide (17) so that contacts (1-4) break and contacts (1-2) make when the set temperature differential is reached. The contacts changeover again when the temperature differential rises to the set value plus the fixed contact differential of approx. 2°C. RT differential thermostat
Regulation range The temperature differential between LT and HT sensors within which the unit can be set to operate. Indicated on the thermostat scale.
Contact differential The temperature rise on the HT sensor over the set temperature differential which causes the switch contacts to make or break.
Scale indication The difference between the temperature on LT and HT sensors at the moment when the switch contacts change over as a result of the downward movement of the spindle.
Reference sensor The sensor that is placed in the medium whose temperature is not affected by the function of the thermostat (HT- or LT sensor).
Operating range The temperature range of the LT sensor, within which the differential thermostat can operate.
Danfoss A/S, 05 - 2002
Example Set differential = 4°C. Switch breaks at 4°C differential and remakes at 4 + 2 = 6°C.
Technical leaflet - RD5EA302
Control sensor The sensor that is placed in the medium whose temperature must be controlled (LT- or HT sensor).
53
Thermostats, differential thermostats, type RT
Setting of differential
The knob can be used to make a setting on the range scale for the lowest temperature at which the contact system must be activated (cut-out or cut-in).
Nomograms for obtained differentials
A = Range setting B = Obtained differential C = Differential setting
54
Technical leaflet - RD5EA302
The differential roller 19 must then be used to set the differential. The highest activating temperature at the sensor is equal to the activating temperature + the set differential.
Danfoss A/S, 05 - 2002
Thermostats, differential thermostats, type RT
Dimensions and weight Weight approx. 1 kg
RT thermostat housing
RT 140, 140L
Danfoss A/S, 05 - 2002
RT 4, 11, 16L, 17, 34
RT 2, 3, 7, 9, 10, 13, 101
Technical leaflet - RD5EA302
RT 8, 8L, 14, 14L, 15, 107, 270
RT 12, 23, 24
RT thermostat housing
RT 102
55
Universal thermostat Type UT Introduction
The UT thermostat is a temperaturecontrolled electric switch with stainless steel (18/8) or copper capillary and sensor. The temperature can be set easily and accurately using the large knob on the front of the thermostat. The temperature must be set to correspond to the required mean temperature. The thermostat has a fixed differential. The temperature must be set in accordance with the required mean temperature. Electric connections are made by means of cable clamps and terminal screws. AMP quick connectors may be used in connection with cabinet mounting. UT is available for wall or panel mounting, and can be used for: • • • • • • •
Approvals
Technical data
Cold rooms Beverage coolers Ice cream makers Milk coolers Refrigerated counters Air-conditioning plant Heat recovery systems
CE-marked according to the low voltage directive EN 60335-1 and the electromagnetic compatibility directivesEN 60335-1, and in accordance with the EMC Directive EN 50082-1 and EN 55014 for sale in Europe Function range UT 72 (for universal purposes) UT 73 (for frost protection) Ambient emperature Reset Differential Switch system Contact load Capillary tube Sensor Sensor
Danfoss A/S (RC-CM/hbs), 09 - 2001
Technical leaflet - RD5HA202
–30 → 30 °C –0 → 40 °C –30 → 55 °C Automatic Fixed, 2.3 K Changeover (SPDT) switch AC 1: 10 A, 250/380 V (ohmic) AC 11: 2.5 A, 250/380 V (induct.) Copper or 18/8 steel Copper or 18/8 steel UT for wall mounting: IP 20 to EN 60529/IEC 529 UT for building in: IP 00 to EN 60529/IEC 529
57
Universal thermostat, type UT
Code numbers Version
Type
UT 72 UT 72 Wall mounting UT 72 UT 72 UT 73 UT 72 Building in UT 72 UT 73 1) 2)
Range
Differential
°C –30 → 30 –30 → 30 –30 → 30 –30 → 30 0 → 40 –30 → 30 –30 → 30 0 → 40
K 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3
Reset
aut. aut. aut. aut. aut. aut. aut. aut.
Max. Capillary sensor tube temperature length °C m 60 1.5 60 1.5 60 1.5 60 3.0 90 1.5 60 1.5 60 3.0 90 1.5
Code no. Copper 060H1101 060H11031) 060H11042) 060H1105 060H1102 060H1201 060H1205 060H1202
18/8 060H1106
UT 72 060-1067 060-1090 060-1070
UT 73 060-1096 060-1090 060-1070
Incl. bulb clamps Industrial pack
Accessories 48 setting knobs 36 pcs. bulb clamp 324 screws/clamps for installation
Dimensions and weight
UT for wall mounting
UT for panel mounting
Weight 0.2 kg
Type
(Dimensions in mm)
58
Technical leaflet - RD5HA202
UT 72 UT 73
Weight 0.1 kg A Copper
B 18/8
max. 147 max. 132 max. 168 -
Copper
18/8
1.5 1.5
0.9 -
Danfoss A/S (RC-CM/hbs), 09 - 2001