I. Characteristics of the cables
1. Using factory prefabrication methods can substantially reduce the site construction labor intensity and shorten the construction laying time;
2. Use of cables can guarantee great length and bending property, and greatly facilitates the construction in a complex place;
3. Use of cables reduces the laying space, and cables can be installed together with gas and hydraulic gas pipelines;
4. Their reliability and reliability can be fully guaranteed, for the cables are manufactured in the factory,
5. Sub-branch parts should use high strength sealed joints, which are waterproof and have properties of moisture protection, long-term maintenance and free for repair;
6. Because the cables are directly connected with households with no need of maintenance and repair and with easy and simple construction, the cables can produce significant comprehensive economic benefits.

II. Usage of the cables:
1. To be used for high-rise building;
2. To be used for disaster prevention equipments;
3. To be used for tunnel lighting and disaster prevention equipments;
4. To replace copper bus bar with small or medium capacity in various places.

III. Standards of the cables
IEC 60502 Rated Voltage 1 ~ 30KV extruded insulated power cables and accessories (International Electrotechnical Commission standards)
GB 12706 Rated voltage 35KV and below Copper core, Aluminum core plastic insulated power cable (National Standard of the People's Republic of China)
JCS 376 branch cable (Japanese Electric Wire Industry Standard)
General Rules for JIS C2810 indoor wiring electrical connection pipes (Japanese Industrial Standard)

Types of the cables:：
Standard main cables and branch cables are all low-voltage power cables with XLPE or PVC insulation materials (IEC, GB, JIS, BS ... ...), and PVC materials covered on the outer side. Generally, the main cable is single-core or twisted multi-core cable (cables with two to five cores), the branch cables are single-core cables, and may adopt a fire-resistant, flame retardant cables in accordance with the requirements.

Their structures and types are as follows: