Isolation Switch Function

1. After opening, establish a reliable insulation gap and separate the equipment or line that needs maintenance from the power supply with a clear disconnection point to ensure the safety of maintenance personnel and equipment.
2. Change the wiring according to operational needs.
3. It can be used to open and close small currents in the circuit, such as the charging current of bushings, busbars, connectors, and short cables, the capacitive current of switch equalizing capacitors, the circulating current during double bus switching, and the excitation current of voltage transformers.
4. According to the specific situation of different structural types, it can be used to open and close the no-load excitation current of a certain capacity transformer.
Isolation switches are mainly suitable for low-voltage terminal distribution systems such as residential buildings and buildings in low-voltage equipment. Main function: Breaking and connecting lines without load.
1. Used to isolate the power supply and disconnect the high-voltage maintenance equipment from the live equipment, so that there is a clearly visible disconnection point between them.
2. The isolation switch is combined with the circuit breaker to perform the switching operation according to the needs of the system operation mode, in order to change the system operation wiring mode.
3. Used to connect or disconnect small current circuits.
Generally, a set of isolation switches are installed on both sides of the circuit breaker, with the aim of isolating the circuit breaker from the power supply and forming a clear disconnection point; Because the original circuit breaker used an oil circuit breaker, which requires frequent maintenance, there should be obvious disconnection points on both sides to facilitate maintenance; In general, the outgoing cabinet is powered down from the upper busbar through the switchgear. In front of the circuit breaker, a set of isolation switches is required to isolate it from the power supply. However, sometimes there is a possibility of an incoming power from behind the circuit breaker, such as reverse transmission through other loops or capacitors. Therefore, a set of isolation switches is also required behind the circuit breaker.
The isolation switch is mainly used to reliably isolate the parts that need to be cut off from the live parts in the high-voltage distribution device, in order to ensure the safety of maintenance work. The contacts of the isolation switch are all exposed in the air and have obvious disconnection points. The isolation switch does not have an arc extinguishing device, so it cannot be used to cut off load current or short circuit current. Otherwise, under high voltage, the disconnection point will generate a strong arc, which is difficult to extinguish on its own, and can even cause flashover (phase to ground or phase to phase short circuit), burn equipment, and endanger personal safety, This is a serious accident called "pulling the isolation switch with load". Isolation switches can also be used to switch certain circuits to change the operation mode of the system. For example, in a dual bus circuit, an isolation switch can be used to switch the running circuit from one bus to another. At the same time, it can also be used to operate some small current circuits.