From high voltage to low voltage, the distribution room of the residential quarter has high voltage incoming cabinet PT cabinet (metering cabinet) and high voltage outgoing cabinet transformer.

High-voltage incoming cabinet is the first cabinet introduced from external power supply, which contains incoming switch, PT cabinet is the protection cabinet for over-current and over-voltage, CT cabinet is the high-voltage metering cabinet for calculating consumption, high-voltage outgoing cabinet is the outgoing cabinet of transformer for changing high voltage into low voltage, and low-voltage incoming cabinet is the low-voltage incoming terminal with switch, and feeder cabinet is the outgoing cabinet with multiple switches. Convey to various motors, etc. The compensation cabinet is a capacitor cabinet for reactive power compensation, and the contact cabinet is used for communication. Only when two or more transformers are used together can there be a connection cabinet. During normal operation, the low-voltage cabinets at the outlet of each transformer operate independently. If a transformer can be stopped sometimes when the power load is not large, then two groups of low-voltage cabinets can be connected one after another, or when one transformer fails, the other one is also used for wiring. There is an interlock in the junction box. When both transformers are electrically operated, the switch of the junction box cannot be operated, except for parallel operation. The sequence is: high voltage incoming cabinet, PT cabinet, CT cabinet, metering cabinet, outgoing cabinet, outgoing cabinet …, transformer, low voltage incoming cabinet, compensation cabinet, feeder cabinet (also called outgoing cabinet) junction box.