power cable Function, structure and characteristics of ring network unit:
(1) Function: power cable ring network unit, also known as ring network cabinet or switch, is used for Medium voltage power cable Segmentation. Contact and tap load. The power cable ring network unit can be divided into indoor and outdoor types according to the applicable places, and can be divided into integral type and interval type according to the structure.
(2) Structure: power cable ring network unit is generally composed of bus, disconnector, load switch, circuit breaker, fuse, grounding switch, incoming and outgoing line bushing, insulated gas chamber, metal protective cover, live display device (with secondary phase drinking hole), grounding device, base, etc.
(3) Features: Due to the combination of components with various functions, the power cable ring network unit can realize many preset functions in the cable network. It can realize the control and protection functions such as opening and closing load current, breaking short circuit current in the cable network, connecting and cutting off overhead lines, power cable lines and no-load transformers, multi circuit power supply for loads with special requirements for power supply reliability, automatic cutting and putting into operation of fault line sections and standby lines, automatic cutting off of user equipment where payment occurs, It is an important equipment in the cable network
The basic structure of power cable consists of core (conductor), insulation layer, shielding layer and protective layer.
Wire core: the conductive part of power cable, used to transmit electric energy, is the main part of power cable.
Insulation layer: electrically isolate the core from the earth and the cores of different phases,
Ensuring power transmission is an indispensable part of power cable structure.
Shielding layer: 15KV and above power cables generally have conductor shielding layer and insulation shielding layer.
Protective layer: to protect the power cable from the invasion of external impurities and moisture, and to prevent external forces from directly damaging the power cable.
