Main role of the isolating switch - Solutions - Huaqiang Electronic Network

Probe domestic switch needle KG-300K needle head diameter is 3.0mm normally open switch needle

100V, 250mA, surface mount, high speed switching diode

Photocoupler

The isolating switch has no special arc extinguishing device in its structure, and it is not allowed to use it to carry out the pulling or closing operation. When the isolating switch is pulled, the isolation switch must be pulled after the circuit breaker cuts off the circuit; when closing, the isolation switch must be connected first, and then the circuit breaker is used to close the circuit. The main function of the isolating switch is:

1. Isolated power supply In the event of power failure maintenance of electrical equipment, the isolating switch is used to isolate the equipment that needs to be shut down for maintenance, and form a clearly visible disconnection point to ensure the safety of workers and equipment.

2. Switching operation The operating state of electrical equipment can be divided into three working states: operation, standby and maintenance. The operation of changing an electrical device from one operating state to another is referred to as a switching operation. For example, in a circuit with double busbar wiring, an isolating switch (called a busbar isolating switch) connected to the busbar can be used to switch the power supply line from one set of busbar power supply to another set of busbars without interrupting the user's power supply.

3, pull, combine no current or small current circuit high-voltage isolating switch, although there is no special arc-extinguishing equipment, but in the process of pulling the brake can cut off the small current, because the moving and static contacts are quickly opened, according to the rapid elongation of the arc The principle of arc extinguishing can extinguish the arc between the contacts. Therefore, the high voltage isolation switch allows the following circuits to be pulled and closed:

1) Pulling and closing voltage transformers and arrester circuits;

2), pull, merge bus and capacitor current directly connected to the bus;

3), no-load transformer with pull and combined excitation current less than 2A: general transformer is 35kV, capacity is 1000kVA and below transformer; voltage is 110kV capacity is 3200kVA and below transformer.

4), the no-load line with the capacitor current not exceeding 5A: the overhead line with a normal voltage of 10kV and a length of 5km or less; an overhead line with a voltage of 35kV and a length of 10km or less.