The building power supply and distribution system refers to the whole circuit of the electric energy from the beginning of entering the building (or cell) to all the terminals of the electric equipment.
Building power supply and distribution system by the total step-down substation (or high voltage distribution), high voltage distribution lines, substations, low-voltage distribution lines and electrical equipment. Two variable voltage power supply system
Large building groups and some of the larger load of medium-sized buildings, generally with a total step-down substation two power supply system, as shown in the following figure. The power supply system generally uses 35-110kv power supply line. After the total step-down substation, the power supply voltage of 35-110kv to 6-10KV, and then through the high voltage distribution lines will be sent to each substation, and then reduced to 380-220v by 6-10KV for low-voltage electrical equipment. Shenzhen lighting engineering high-voltage electrical equipment is directly from the total step-down substation 6-10KV bus power supply. This type of power supply is called the two variable voltage power supply.
Single variable voltage power supply system
General medium-sized buildings or buildings using 6-10KV power supply into the line, the high-voltage power distribution will be distributed to the substation, the substation will be reduced to 380-220v 6-10KV voltage for low-voltage electrical equipment. Similarly, Shenzhen lighting design of high-voltage electrical equipment directly from the high-voltage distribution of the 6-10KV bus power supply.