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Table 26 : Minimum insulation resistance values

Table 27 : Requirements for compatibility of insulation and oversheath

APPENDIX

GUIDES TO USE

CONTENTS

1. Scope

2. Object

3. Recommendations for use

   1. Permissible application

   2. Highest permissible voltage

4. Recommendations for storage and transport and disposal

   1. Storage

   2. Transport

   3. Disposal by incineration

   4. Cable end sealing

5. Recommendations for cable laying and installation

   1. General

   2. Environmental conditions

   3. Pulling tensions

   4. Bending radii

   5. Cable installation

1. Tests after installationScope

This Appendix covers the application of cables according to HD604 Section E Part 3.

2. Object

The object of this document is to provide recommendations for the selection, storage, disposal, transportation and installation of the cables specified under clause 1. The information given in this Appendix is for guidance only. It does not take precendence over any relevant national regulations or statutory requirements.

3. Recommendations for use

   1. Permissible application

These cables may be installed indoors and outdoors for fixed installations on walls and metallic structures. These cables shall not be installed where the emission of corrosive fumes and excessive smoke in the event of a fire are forbidden.

These cables may be used on Category А, В & C of IEC 183.

4. Recommendations for Storage, Transport and Disposal

   1. Storage

Cable drums should be regularly inspected to assess their physical condition.

Battens, when supplied, should not be removed until cable is required for installation.

Cable drums having a flange diameter exceeding 1m and weighing more than 250 kg gross shall be transported in an upright condition. The drums should be protected against movement. Loading and unloading shall be facilitated by suitable devices to avoid damage to both cable and drum. When moving drums due regard must be paid to the weight, method and direction of rolling, protruding nails and wood splinters.

Small quantities of timber or battens which may have been treated with wood preservative may be burnt under carefully controlled conditions in the open. Cables shall only be incinerated under the supervision of a licensed contractor.

Both ends of every length of cable shall be sealed in such a manner as to include the oversheath and to inhibit the ingress of moisture during storage, delivery and up to the time of jointing.

5. Recommendations for cable laving and installation

   1. General

The choice of cable shall take into account the cable route, method of laying and service conditions.

The latter shall include:

1. The adjacency of other cables and their mutual heating effect; the specific earth resistivity, protection against solar radiation; the earth loop impedance; the capability of the cable to withstand the worst anticipated fault conditions of the system;

2. The leakage of stray currents and attack from solvent substances;

3. Soil subsidence and other forms of violent vibrations;

4. Protection against mechanical damage during and after installation;

5. When cables are laid in ducts, the correct size of duct shall be used to avoid damage during installation and overheating;

6. Where cables are laid in surface troughs, there shall be adequate ventilation which, however, will not permit the entry of debris;

7. The cable support system should be designed to avoid damage or danger under normal or fault conditions.

The lowest recommended temperatures for installation shall be 0°C but care should be taken to ensure that the cable temperature has been above 0°C for the preceding 24 hours.

The maximum pulling load shall not exceed the following values.

For copper conductors 50N/mm^! of CSA

For aluminium conductors 30N/mm² of CSA

CSA refers only to the conductor(s).

Where long lengths of cable are to be pulled along difficult routes, where the tension increases sharply due to bends, cognisance shall be taken of the values for maximum side wall pressure (tension divided by bending radius) recommended by the supplier.

During installation, no cable shall be bent to a smaller radius than those listed below.

1. Armoured circular copper conductor 6 x D

2. All other cables 8 x D

1. There shall be a significant measure of compatibility between the way in which cables are installed for the test for fire propagation and the actual installations.

2. There shall be compatibility between all jointing materials and components of the cable.

3. All bonds for earthing shall have adequate conductance, be as short and as straight as possible and be protected against corrosion, especially where dissimilar metals are involved.

6. Tests after installation

These are not mandatory, but when required shall consist of:

(a) D.C. tests on cables

The test voltage, given in table A.1 should be increased gradually to the full value and maintained continuously for 15 minutes. The test should be made between conductors and between each conductor and metallic covering. No breakdown should occur. Repeated d.c. voltage tests may damage the insulation.

Table A.1. : Test voltage after installation

Where an outer conductive layer is applied to the oversheth, a d.c. voltage of 3kV shall be applied between the underlying armour and the outer conductive layer for one minute. No breakdown should occur

.SECTION В : CABLES WITH COPPER OR ALUMINIUM
CONDUCTORS AND TAPE ARMOUR

Replace pages 4-B-4, 4-B-7, 4-B-8, 4-B-11, 4-B-12, 4-B-14 and 4-B-17 by the following-.'BLANK PAGE'

The metre marking (accurate to within ± 1 %) is marked in white colour on another axis of the cable.

2.3 Additional test requirements

After completion of the voltage test given in sub-clause 2.3.1.1 above and when a sample of core is tested in accordance with sub-clause 3.3.1 of HD 605, the Ki value shall not be less than:

3670 MD.km at 20°С

3.7 Ma.km at 80°C

When tested in accordance with sub-clause 3.6.2 of HD 605 using a test voltage as specified in 3.6.2.2 C, the oversheath shall not fail.

Alternatively, the test can be as specified in sub-clause 3.2.3.1 of HD 605 using a test voltage of 10 kV de or 3 kV ac for a duration of one minute, without failure of the oversheath.

When a sample of complete cable is tested in accordance with sub-clause 2.1.3.1 of HD 605, the values obtained for the external diameter shall fall within the extreme values agreed between manufacture and purchaser.

After a sample of complete cable has been tested in accordance with sub-clause 2.4.1.1 of HD 605, it shall be subjected to the voltage test given in sub-clause 2.3.1.2. No breakdown shall occur and the sheaths shall not show any tear or crack.

The test temperature shall be ambient temperature.

The diameter of the test cylinder shall be:

12 D ± 5%

where D is the actual external diameter of the cable sample, in mm.2.3.6 Thermal endurance test for power cable

When an approximately 40 m length of complete cable is tested in accordance with sub-clause 5.1.5 of HD 605, no breakdown of the cable shall occur.

The test conditions shall be as follows:

1. conductor temperature (90±5)°C

2. time duration 5000 h

3. number of thermal cycles 210

On completion of this test, the sample shall be subjected to:

(a) voltage test according to sub-clause 2.3.1.1: the insulation shall not break down;

lb) insulation resistance check: the Ki value shall meet the requirements given in sub-clause 2.3.2;

3. checking the behaviour under fire conditions by test given in sub-clause 4.1.2 of HD 605: it shall meet the requirements given in 2.3.8 below;

4. the measurement of mechanical properties of the insulation and sheaths: it shall be carried out in accordance with sub-clause 9.1 and 9.2 of HD 505.1.1: the results of the tests are noted for information.

2.3.7 Thermal endurance test for control cable

The test shall be carried out in accordance with sub-clause 5.1.4 of HD 605 under the following conditions:

1. conductor temperature |90±2)°C

2. time duration 1008 h (42 days).

At the end of the ageing procedure:

1. The Ki value shall meet the requirements specified in sub-clause 2.3.2;

2. the measurement of mechanical properties of the insulation and sheaths: it shall be carried out in accordance with sub-clause 9.1 and 9.2 of HD 505.1.1; the results of the tests are noted for information.

2.3.8 Flame propagation test

The characteristics of the cable shall be such that it meets the performance requirements of HD 405.1 and that, after having been tested in accordance with sub-clause 4.1.2 of HD 605, the two test pieces of cable shall comply with the following condition:

On visual inspection, the part of the test piece located above the top of the chimney shall show no trace of combustion.

C

3.

ables without metallic covering

Not applicable.Table 1 * Requirements for the non-electrical tests for ethylene propylene rubber insulation