The function of the isolation switch
Release time:
2023-02-11
After switching off, establish a reliable insulation gap to isolate the equipment or line that needs to be inspected and repaired from the power source with a clear disconnection point to ensure the safety of maintenance personnel and equipment. 2. Change the line according to the operation needs. 3. It can be used to switch on and off small currents in the line, such as the charging current of bushings, busbars, connectors, short cables, the capacitive current of switch equalizing capacitors, the circulating current during double busbar switching, and the excitation current of voltage transformers, etc.
1. After switching off, establish a reliable insulation gap, isolating the equipment or line requiring maintenance from the power source with a clearly visible disconnect point to ensure the safety of maintenance personnel and equipment.
2. Change the lines according to operational needs.
3. It can be used to switch small currents in lines, such as the charging current of bushings, busbars, connectors, and short cables, the capacitive current of switch equalizing capacitors, the circulating current during double busbar switching, and the excitation current of voltage transformers, etc.
4. Depending on the specific situation of different structural types, it can be used to switch the no-load excitation current of a certain capacity transformer.
In low-voltage equipment, isolating switches are mainly used in residential houses, buildings, and other low-voltage terminal distribution systems. Main function: disconnecting and connecting lines without load.
1. Used to isolate the power source, disconnecting the high-voltage maintenance equipment from the energized equipment, creating a clearly visible disconnect point.
2. The isolating switch works with the circuit breaker to perform switching operations according to system operational needs, changing the system's operating wiring method.
3. Used to connect or disconnect low-current circuits.
Generally, a set of isolating switches is installed on both sides of the circuit breaker. The purpose is to isolate the circuit breaker from the power source, forming a clear disconnect point; because the original circuit breaker was an oil circuit breaker, the oil circuit breaker requires frequent maintenance, so there must be a clear disconnect point on both sides for easy maintenance; generally, the outgoing cabinet is powered from the upper busbar through the switchgear downwards. A set of isolating switches is needed in front of the circuit breaker to isolate it from the power source, but sometimes, the circuit breaker may also receive power from the rear, such as through other loops, reverse feeding from capacitors, and other devices, so a set of isolating switches is also needed behind the circuit breaker.
Isolating switches are mainly used to reliably isolate the part requiring power outage from the energized part in high-voltage distribution equipment to ensure the safety of maintenance work. The contacts of the isolating switch are all exposed in the air, with a clear disconnect point. The isolating switch has no arc-extinguishing device, so it cannot be used to cut off load current or short-circuit current; otherwise, under high voltage, a strong arc will be generated at the disconnect point, and it is difficult to extinguish itself, and it may even cause arcing (relative or phase-to-phase short circuit), damaging equipment, and endangering personal safety. This is the so-called serious accident of "pulling the isolating switch under load." The isolating switch can also be used for switching operations of certain circuits to change the system's operation mode. For example, in a double busbar circuit, an isolating switch can be used to switch the running circuit from one busbar to another. At the same time, it can also be used to operate some low-current circuits.
→Related information
Address: 15th Floor, Building 1, Zhong Geng Hong Ding Tian Xia, No. 61 Nan Road, Cangshan District, Fuzhou City, Fujian Province
Postcode: 350007
Mobile
