Selection Of Isolation Switch Configuration

Configuration selection
Selection of isolation switches
The isolation switch is configured on the main wiring [6] to ensure a clear isolation between the open circuit and the live part during maintenance of the line and equipment. Due to the lack of arc extinguishing device and low breaking capacity of the isolation switch, the switching operation sequence must be followed when operating the isolation switch. That is, when transmitting power, the bus side isolation switch should be closed first, followed by the line side isolation switch, and finally the circuit breaker. In case of power outage, the opposite is true.
Configuration of isolation switches
1. Both sides of the circuit breaker should be equipped with isolation switches to create a clear break and power isolation during circuit breaker maintenance.
2. Ordinary transformers with directly grounded neutral points should be grounded through isolation switches.
3. The lightning arrester and voltage transformer on the busbar should share a set of isolation switches to ensure the safety of electrical and busbar maintenance. Each section of busbar should be equipped with 1-2 sets of grounding switches.
4. The lightning arrester connected to the outgoing line or neutral point of the transformer may not be equipped with an isolation switch.
5. When there is no power supply on the user side of the feeder line, the side of the circuit breaker leading to the user may not be equipped with an isolation switch. But to prevent lightning overvoltage, it can also be installed.