MODUK DEF STAN 61-012: PART 04 PDF

The cores of the cables specified are insulated with PVC and are suitable for operation as follows:

Cores with 7/0.1 mm conductors, voltages up to 250 V RMS at frequencies up to 1.6 kHz.

Cores with 7/0.2 mm conductors, voltages up to 440 V RMS at frequencies up to 1.6 kHz.

Current carrying capacities for the cables are not given owing to the varied conditions of loading and construction. However, for guidance, where a single core of a multi-core cable is loaded, the current in a 7/0.1 mm conductor should not exceed 250 mA, in a 7/0.2 mm conductor the current should not exceed 1 A.

The recommended maximum (conductor) operating temperature for the cables in Table 7, Table 8 and Table 9 is 70 ºC but they may be operated at slightly higher temperatures for short periods. No definite limit can be given for low temperature because conditions of use are varied and include, for example, the rate of bending, the radius of bending and the length of time the cable is exposed to the low temperature. PVC compounds become increasingly stiff and brittle as their temperature decreases, with the result that if the cable is bent too sharply at temperatures lower than about 0 ºC there is risk of shattering the PVC.

Although the insulation and jacket of the cables are tested in a specified manner at temperatures down to -15 ºC and -30 ºC respectively and although in storage and when once installed (but not subjected to flexing or severe vibration) the cables can withstand temperatures as low as -55 ºC, it is recommended that they should not be bent in handling unless cable and ambient temperatures are above 0 ºC and have been so far the previous 24 hours, or unless special precautions have been taken to maintain the cable above this temperature.

Historic cables meeting the requirements of Defence Standard 61-012 Pt 4 have not been tested for compliance with Defence Standard 07-247 and are therefore prohibited from use in submarines and ships. Future design requirements shall give consideration to tests detailed in DS 07-247 and if those tests are not viable, then agreement shall be sought from the Authority that they will not be completed. Agreement shall be provided in writing from the appropriate authority.