TR2029 Issue D January 2008

NMCS Inductive Loop Detector Cable

© Crown Copyright 2008 First published 1994 Printed and published by the Highways Agency

1

NMCS INDUCTIVE LOOP DETECTOR CABLE

TR 2029 Issue D

Contents

Page

Equivalence Statement

1

1

Scope

1

2

Normative References

1

3

Definitions

2

4

Cable Configuration

2

5

General Construction

2

6

Electrical Requirements

5

7

Manufacturers Test

6

Issue History

6

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TR 2029 D

Equivalence Statement, Scope and Normative References

EQUIVALENCE STATEMENT Any requirements of this specification for goods or materials must be made in accordance with the Manual of Contract Documents for Highway Works, Volume 1 - Specification for Highways Works, Series 100 – Preliminaries, Clause 104.

1

SCOPE This technical Regulation details the materials to be used, the construction and the performance requirements of inductive loop detector cables used by the Highways Agency, an Executive Agency of the Department of Environment, Transport and Regions on the National Motorway Communications System (NMCS). It is to be read in conjunction with MCH 1936 "NMCS Cables – General Technical Requirements" which details the general requirements for all NMCS cables.

2

NORMATIVE REFERENCES The following standards contain provisions which, through reference in this text, constitute provisions of this Technical Regulation. All standards are subject to revision and parties using this Technical Regulation shall apply the most recent editions of the standards indicated below. Members of the IEC and ISO maintain registers of currently valid international standards. ISO 472

Plastics Vocabulary

IEC 60050

International Electrotechnical Vocabulary

IEC 60228

Conductors of Insulated Cables

IEC 60811

Common Test Methods for Insulating and Sheathing Materials of Electric cables.

BS 6500

Electric Cables – Flexible cords rated up to 300V/500V for use with insulation and equipment (no international equivalent)

MCH 1936

January 2008

NMCS Cables – General Technical Requirements

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TR 2029 D

3

Definitions, Cable Configuration and General Construction

DEFINITIONS For the definition of terms within this Technical Regulation refer to: ISO 472 Plastics Vocabulary IEC 60050 International Electrotechnical Vocabulary The “Authority” or the “Overseeing Organisation” is the Highways Agency, Scottish Office Development Department, National Assembly for Wales or the Department of the Environment for Northern Ireland, depending on which is responsible for the Contract.

4

CABLE CONFIGURATION The cable configuration shall be stated in the contract, which shall specify: a) Any special requirements; b) Lengths.

5

GENERAL CONSTRUCTION 5.1

Description This cable is a single core multistrand flexible cable sheathed with polychloroprene designed for installation in a slot cut into the carriageway. Following installation the cable is covered with epoxy resin and the slot is backfilled with hot pour bitumen. The single tinned copper conductor is insulated with ethylene propylene rubber.

tin coated anneald copper conductors ethylene propylene rubber black polychloroprene

This Drawing is provided for illustrative purposes only

January 2008

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TR 2029 D

5.2

Definitions, Cable Configuration and General Construction

Conductors 5.2.1 Material The cable conductor shall consist of 30/0.25mm wires of tin coated plain annealed copper. They shall be smoothly drawn, circular in section, uniform in quality, free from defects and shall comply with IEC 60228 for Class 5 flexible conductors. The cross sectional area 2

of the conductor shall be l.5mm . The overall diameter of the conductor shall not exceed 1.8mm in accordance with IEC 60228.

5.3

Insulation 5.3.1

Material The conductor shall be covered with ethylene propylene rubber (EPR) and shall comply with the test requirements of ordinary duty compound GP1, 85oC insulation as specified in Table 1.

Test

Requirements

Tensile properties of unaged test pieces: Minimum tensile strength. N/mm2

4.2

Minimum elongation at break, %

200

Tensile properties after accelerated ageing in air bomb, 42h at 127 ± 1°C Tensile strength: minimum percentage of value for unaged samples, %

60

Elongation at break: minimum percentage of value for unaged samples, %

60

Table 1. Test Requirements for 850C Insulation 5.3.2

Insulation Thickness The insulation radial thickness shall be a nominal 0.8mm when measured in accordance with IEC 60811 and BS 6500. The minimum thickness shall not fall below this value by an amount more than 10% + 0.1mm.

January 2008

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TR 2029 D

Definitions, Cable Configuration and General Construction

5.3.3

Colour The insulation shall be black.

5.4

Cable Sheath 5.4.1

Material The cable shall be sheathed with black polychloroprene and shall comply with the test requirements of compound type RS3 heavy-duty oil-resisting and flame retardant sheath for operation at 85oC as specified in Table 2. Test

Requirements for sheath

Tensile properties of unaged test pieces Minimum tensile strength, N/mm2

8.0

Minimum elongation at break, %

250

Tensile properties after ageing in air bomb, 42h at 127 ± 1°C Tensile strength: minimum percentage of value for unaged sample

50

Elongation at break: minimum percentage of value for unaged sample

50

Tensile properties after ageing in oil, 24h at 100 ± 2°C Tensile strength: minimum percentage of value for unaged sample %

60

Elongation at break: minimum percentage of value for unaged sample %

60

Hot set test at 200 ± 2°C stress on test piece 0.2N/mm2 Maximum elongation % Maximum permanent elongation %

175 25

Table 2. Test Requirements for 850C Sheath

5.4.2

Sheath Thickness The sheath radial thickness shall be a nominal l.4mm when measured in accordance with IEC 60811 and BS 6500. The minimum thickness shall not fall below this value by an amount more than 15% + 0.1mm.

January 2008

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TR 2029 D

General Construction and Electrical Requirements

5.4.3

Bonding The sheath shall be closely bonded to the insulation in a manner, which prevents separation during stresses imposed by handling and installation.

5.4.4

Colour The sheath shall be black.

5.5

External Diameter The external diameter of the cable shall be between 5.8mm and 7.2mm when measured in accordance with IEC 60811 and BS 6500.

5.5.1

Ovality The cable shall comply with the requirements of BS 6500 with regards to ovality.

5.6

Marking

5.6.1

The cable shall be identified throughout its length by the legend `HEAT RESISTING 85oC' in accordance with BS 6500.

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ELECTRICAL REQUIREMENTS 6.1

General All testing shall be carried out in accordance with the requirements of BS 6500.

6.2

Conductor Resistance The d.c. resistance of the conductor when corrected to 20oC in accordance with IEC 60228 shall not exceed 13.7 ohms per kilometre of cable.

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TR 2029 D

Electrical Requirements, Manufacturer’s Tests and History

6.3

Insulation Resistance After steady electrification for not less than 60 seconds, the insulation resistance shall be not less than 665/L MΩ, where L = length of cable in kilometres.

7

MANUFACTURER'S TESTS 7.1

The manufacturer shall define a quality plan for testing which shall include details of tests required by this Specification. The quality plan shall be submitted to the Authority for acceptance.

7.2

The manufacturer shall carry out the tests specified in BS 6500, in accordance with BS 6500.

7.3

7.4

The following Acceptance Tests shall be carried out on all drum lengths of cable: •

Conductor Resistance in accordance with Clause 6.2.

•

Insulation Resistance in accordance with Clause 6.3.

The manufacturer shall provide documentation detailing the results of 5.3 and 5.4.1. The documentation shall be submitted to the Authority for acceptance.

ISSUE HISTORY

Issue

Amendments Since Previous Issue

Approved By

Date

B.John

28/07/1994

B

Reformatted

C

Detail Changes

Brian Oliver

28/.03/2002

D

Additions and changes as side-lined marked

Brian Oliver

31/01/2008

Brian Oliver

January 2008

Digitally signed by Brian Oliver DN: cn=Brian Oliver, c=