Main maintenance standards of office electrical equipment

Applicable to the maintenance of power supply and distribution equipment and facilities in the border area of property management companies.

Commonly used AC power supply methods in power distribution system are:

① Three-phase three-wire system. It is divided into triangle wiring (0.4kv motor and lighting) and star wiring (used for low-voltage three-phase 0.23kv industrial lighting distribution and 0.23kv three-phase motor).

② Three-phase four-wire system. Used for 0.4kv/0.23kv low-voltage power and lighting mixed distribution.

③ Three-phase, two-wire and one system. Mostly used in rural power distribution (because security problems have long been eliminated).

Commonly used DC power supply modes in power distribution system are:

① Two-wire system. Used for power supply of urban trolleybuses, subway locomotives, mine traction locomotives, etc.

② Three-wire system. Supply power plants, substations, distribution stations, secondary equipment, electrolysis, electroplating.

The primary distribution network is the network from the outlet of the distribution station to the entrance of the distribution station (or substation). It is also called high voltage distribution network in China. The voltage is usually 6 ~ 10 kV, and 10 kV distribution is often used in cities.