Service characteristics and operating conditions of insulated overhead cables:
1. Service characteristics and operating conditions of insulated overhead cables
2. The crosslinking polyethylene insulation overhead cable core maximum working temperature of 90 ℃ for a long time, high density polyethylene insulation 75 ℃, polyvinyl chloride (PVC) is 70 ℃
3. When the environment temperature is not lower than laying - 20 ℃
4. The bending radius is allowed when laying. When the rated voltage is less than 1kv, it is not less than 6 times the outer diameter of the cable, and the rated voltage is less than 10kv, not less than 15 times the outer diameter of the cable
Above 10kv insulated overhead cables can be used for systems with single-phase grounding fault time generally no more than 1min at a time, or for systems with a maximum of 8h at a time and a cumulative time of no more than 125h at a time.
When a short circuit (the longest duration of no more than 5 s) the highest temperature of the cable, cross-linked polyethylene insulation 250 ℃ high density polyethylene edge 150 ℃
10 kv overhead insulated cable insulation resistance shall be not less than 1500 m Ω • km, thin insulation results of cable insulation resistance shall be not less than 1000 m Ω • km, the user can be used according to the requirement for tension size to choose.