Miniature Circuit Breakers Reliable solutions for protection of installations against over-current phenomenon

Advantages for you :

Technical data :

• Bi-connect terminals for simultaneous termination of bus bar & wires

• Conforms to IEC 60898-1, IS/IEC 60898-1:2002

• Unique pull up terminals design with safety shutters for enhanced safety of users • Positive contact indicator

• Ratings – 0.5 to 63 A • No. of poles – 1P, 2P, 3P & 4P • Tripping characteristics – B, C & D curves

• Line-load reversibility • Low watt losses, saves energy

• Breaking capacity – 10kA (as per IS/IEC 60898-1:2002)

• High electrical life

• Suitable for Isolation as per IEC 60947

• Wide range of accessories eg U/V release, over-voltage release, shunt release, Aux & trip alarm conatcts

• CE and RoHS compliant

Expert tips Positive contact indicator Red : ON Green : OFF – more safety to the user – positive contact indication – indicates actual contact position

10kA breaking capacity with energy limitation class 3 – high breaking capacity – better protection of cables and equipments – low let through energy – line load reversible

User friendly terminal design – bi-connect terminal – pull-up design – safety shutter (IP2X)

Wide range of accessories – – – –

overvoltage release MZ209 undervoltage release shunt release auxiliary contact & trip alarm contact for on-off & trip indication

Miniature circuit breakers 10kA type NB, NC, ND Description • Protects circuits against overload & short circuit faults • Provides isolation to downstream circuits

Technical data • Conforms to IEC 60898-1:2002 IS/IEC 60898-1:2002 • Ratings - 0.5 to 63 A • No. of poles - 1P, 2P, 3P & 4P • Tripping curves - B, C & D • Breaking capacity 10kA (as per IEC 60898-1) 15kA (as per IEC 60947) • Suitable for isolation as per IEC 60947 Description

Modules

In (Amp)

1P

1 1 1 1 1 1 1 1 1 1 1 1 1 1

0.5 1 2 3 4 6 10 16 20 25 32 40 50 63

2 2 2 2 2 2 2 2 2 2 2 2 2 2

0.5 1 2 3 4 6 10 16 20 25 32 40 50 63

3 3 3 3 3 3 3 3 3 3 3 3 3 3

0.5 1 2 3 4 6 10 16 20 25 32 40 50 63

4 4 4 4 4 4 4 4 4 4 4 4 4 4

0.5 1 2 3 4 6 10 16 20 25 32 40 50 63

NC110N

2P

NC220N

3P

NC316N

4P

NC432N 40

Features & benefits • Positive contact indicator on front face • 10kA breaking capacity with class 3 energy limitation • Bi-connect terminals with pull-up design • Finger proof (IP2X) terminal with safety shutters • Line-load reversible

• RoHS compliant, “Green” product • Wide range of accessories are available Connection 25sq mm rigid cables 16sq mm flexible cables

B Curve

C Curve

D Curve

NB106N NB110N NB116N NB120N NB125N NB132N NB140N NB150N NB163N

NC100N NC101N NC102N NC103N NC104N NC106N NC110N NC116N NC120N NC125N NC132N NC140N NC150N NC163N

ND100N ND101N ND102N ND103N ND104N ND106N ND110N ND116N ND120N ND125N ND132N ND140N ND150N ND163N

NB206N NB210N NB216N NB220N NB225N NB232N NB240N NB250N NB263N

NC200N NC201N NC202N NC203N NC204N NC206N NC210N NC216N NC220N NC225N NC232N NC240N NC250N NC263N

ND200N ND201N ND202N ND203N ND204N ND206N ND210N ND216N ND220N ND225N ND232N ND240N ND250N ND263N

NB306N NB310N NB316N NB320N NB325N NB332N NB340N NB350N NB363N

NC300N NC301N NC302N NC303N NC304N NC306N NC310N NC316N NC320N NC325N NC332N NC340N NC350N NC363N

ND300N ND301N ND302N ND303N ND304N ND306N ND310N ND316N ND320N ND325N ND332N ND340N ND350N ND363N

NB406N NB410N NB416N NB420N NB425N NB432N NB440N NB450N NB463N

NC400N NC401N NC402N NC403N NC404N NC406N NC410N NC416N NC420N NC425N NC432N NC440N NC450N NC463N

ND400N ND401N ND402N ND403N ND404N ND406N ND410N ND416N ND420N ND425N ND432N ND440N ND450N ND463N

Miniature circuit breakers 80-125A, 10kA type HLF Description • Protects circuits against overload & short circuit faults • Provides isolation to downstream circuits Technical data • Conforms to IEC 60898-1 IEC 60947 • Ratings – 80A,100A &125A • No. of poles - 1P, 2P, 3P & 4P • Tripping curve - C

• Breaking capacity - 10kA (as per IEC 60898 & 60947) • Suitable for isolation as per IEC 60947

• RoHS compliant, “Green” product • Wide range of accessories are available

Features & benefits: • MCBs handle can be locked in "off" position • Large terminal capacity- upto 70 sq mm • Steel reinforcement plate to improve terminal strength • Serrations on jaws to provide better grip on cables • Line-load reversible

Connection capacity • 35 sq mm flexible wire (50 sq mm possible with some cable end-caps) • 70 sq mm rigid wire IP2X terminals

Description

In (Amp)

Modules

Catalogue No.

1P

80

1.5

HLF180S

100

1.5

HLF190S

125

1.5

HLF199S

80

3

HLF280S

100

3

HLF290S

125

3

HLF299S

80

4.5

HLF380S

100

4.5

HLF390S

125

4.5

HLF399S

80

6

HLF480S

100

6

HLF490S

125

6

HLF499S

HLF199S

2P

HLF299S

3P

HLF399S

4P

HLF499S

41

Circuit protection principle (R1+R2) - where R1 is the resistance of the phase conductor within the installation and R 2 is the resistance of the circuit protective conductor. These two components constitute the loop impedance within the installation.

By referring to the characteristic for NC 132 it can be seen that the breaker will disconnect in 0.02 seconds for this current. The breaker therefore easily satisfies the requirement for disconnection in 5 seconds.

Therefore : Zs = Ze+(R1+R2)

If the circuit Zs was 2.0 ohms that the fault current would be : 240/2 - 120A and the disconnection time would be 10 seconds, in which case compliance would not be achieved.

Once the value of Zs has been established a suitable overcurrent protective device has to be selected to ensure disconnection of an earth fault within the specified time. The times are : • •

5 seconds for fixed equipment For portable equipment and for fixed equipment installed outside the equipotential bonding zone, the disconnection times are dependent on the nominal voltage to earth, i.e. 220 to 277 volts = 0.4 seconds.

An earth fault current of 343A causes a trip of the magnetic protection in 20mS.

Zs by calculation

An earth fault current of 120A causes a trip of the thermal protection in 10 seconds.

To establish whether the relevant disconnection time can be achieved a simple calculation must be made, based on Ohm's law : lf(fault current) = Uo (open circuit voltage)* Zs (earth fault loop) *voltage between phase and earth (240V) The fault current (lf) must be high enough to cause the circuit protective device to trip in the specified time. This can be established by consulting the time/current characteristic for the protective device. If the maximum trip time for the fault current calculated is less than or equal to the relevant value (5s) for fixed equipment; 0.4s for portable equipment) then compliance is achieved. Zs by tables The above procedure can be used for any type of protective device providing a time/current characteristic curve is available. Frequently, however, a much simpler method is available using tables listing maximum Z s values which have been interpreted from the characteristic curves for the relevant devices. Providing the system Zs is equal to or less than the value given in the table, compliance is achieved. Zs too high If the system Z s value is too high to achieve rapid enough disconnection with the Overcurrent protective devices available then it is necessary to use one of the two following methods: •

•

fit a cable with a large cross-section and consequently a lower impedance. This may be a very expensive solution especially when the installation is completed before the problem is discovered. use a Hager residual current device (RCD). Subject to certain conditions being met this provides a simple and economical solution.

Example

Fig. 3 Protection against overcurrent Overcurrent - "A current exceeding the rate value. For conductors the rated value is the current-carrying capacity". Overload current - "An overcurrent occurring in a circuit which is electrically sound". Short-circuit current - "An overcurrent resulting from a fault of negligible impedance between live conductors having a difference in potential under normal operating conditions." Protection against overload current For the protection against overload current, protective devices must be provided in the circuit to break any overload current flowing in the circuit conductors before it can cause a temperature rise which would be detrimental to insulation, joints, terminations or the surrounding of the conductors. In order to achieve this protection the normal current of the protective device ln should not be less than the design current of the circuit lb and that ln should not exceed the current-carrying capacity of the conductors lz, and that the current causing effective operation of the protective device l2 does not exceed 1.45 times the current-carrying capacity of the conductor lz, expressed as lb< ln< lz l2