This Pakistan standard specifies requirements and dimension for rubber-insulated cables and flexible cables for operation at voltages up to and including 450 V to earth and 750 V a.c. between conductors.
The cables are suitable for use where the combination of ambient temperature and temperature rise duo to load results in a conductor temperature not exceeding :
60°C for type Ell rubber insulation,
85°C for type GP1 rubber insulation,
150°C for type E12 rubber insulation, but 180°C if there are no limits imposed by environmental conditions, and in the case of a short-circuit the maximum conductor temperature does not exceed :
200°C for type Ell rubber insulation, 250°C for type GP1 rubber insulation, 350°C for type E12 rubber insulation.
Note :—The above short-circuit temperatures are based on the intrinsic properties of the insulating materials. It is essential that the accessories which are used in the cable system with mechanical and/or soldered connections are suitable for the temperature adopted for the cable.
The type of cable included in the standard are :
Table 1 85°C rubber-insulated, textile brai ded and compounded cable, single core
Table 2 60°C rubber-insulated and sheathed cable, flat twin
Table 3 6C°C rubber-insulated and sheathed flexible cable, single core, circular twin, 3-core, 4-core and 5-core ...
Table 4 85°C rubber-insulated, HOFR shea thed flexible cable, single core, circular twin, 3-core, 4-core and 5-core
Table 5 150°C rubber-insulated, braided, heat resistant flexible cable, single core
450/750 V 300/500 V
450/750 V
450/750 V 300/500 V