The difference between the isolating switch and the circuit breaker

The role of the isolating switch

(1) For isolating the power supply, disconnecting the high-voltage service equipment from the live equipment with a clearly visible break point between them.

(2) The isolating switch cooperates with the circuit breaker, and the switching operation is performed according to the needs of the system operation mode to change the wiring mode of the system operation.

(3) Used to turn on or off the small current circuit. The isolating switch can perform the following operations: it can pull and close the bypass current of the closed circuit switch; pull and close the grounding wire of the neutral point of the transformer, but when the arc suppression coil is connected to the neutral point, only when the system has no fault, Operation; pulling and closing voltage transformers and arresters; pulling and closing busbars and capacitor currents directly connected to the busbar equipment; pulling and closing capacitor currents not exceeding 5 amps of no-load lines; triple-isolated switches capable of pulling and closing voltages at 10 Loads of kilovolts or less and currents of 15 amps or less.

When operating the isolating switch, it should be noted that when the line is powered, the isolating switch on the busbar side is connected first, and the line side isolating switch is connected to the circuit breaker. When the line is out of power, first disconnect the circuit breaker and then open the isolation switch. Can not pull and close the high voltage isolation switch with load.

The difference between the isolating switch and the circuit breaker

The circuit breaker has an arc extinguishing device, so the circuit breaker can be operated with load, not only can operate the load current, but also can operate the fault (short circuit) current; the circuit breaker has a good package form, so simply observe the circuit breaker and cannot intuitively determine that it is In the closed or open position.

The isolating switch does not have an arc extinguishing device. Although the regulations stipulate that it can be operated in a load current less than 5A, the overall operation is not loadable. However, the isolating switch has a simple structure, and its operating state can be seen at a glance from the appearance. Obvious disconnection point.

The circuit breaker is simply referred to as “switch” in use, and the isolating switch is simply referred to as “knife gate” in use, and the two are often used in combination.