The load switch is a control appliance with a simple arc extinguishing device, which can open and close the circuit with load. It can open and close a certain load current and overload current, but it cannot disconnect the short-circuit current. It must be used in series with the high-voltage fuse, with which the short circuit current can be cut off.
Functions of load switch:
1.Switch and close functions.
With certain arc extinguishing capacity, it can be used for breaking and closing load current and overload current of a certain multiple (usually 3-4 times). It can also be used for large no-load transformers with breaking and closing capacity greater than that of disconnectors and long no-load lines. Sometimes it can also be used to open and close large capacity capacitor banks.
2. Substitution effect.
The series combination of load switch and current limiting fuse can replace the circuit breaker. That is, the load switch is responsible for breaking and closing the overload current less than a certain multiple, and the current limiting fuse is responsible for breaking the large overload current and short circuit current.
3. The load switch is a load switch in series with the current limiting fuse. It is specified in national standards as "load switch fuse combination". The fuse can be installed on the power supply side of the load switch or the load switch. When the fuse does not need to be replaced frequently, the former layout mode should be adopted, so that the load switch can be used as an isolating switch to isolate the voltage applied to the current limiting fuse.