What is the operating sequence when isolating switches are used together with load switches？

When closing the load switch, close the isolating switch first and then the load switch. When opening, open the load switch first and then the isolating switch. This is done to avoid phase-to-phase short circuit accidents when the load-pull isolating switch is closed. The isolating switch can only cut off fault-free voltage transformers, lightning arresters, transmission lines of a certain length, no-load transformers of a certain capacity, etc. The load switch can only cut off the rated current and overload current. Both switches are not allowed to cut off the short-circuit current. If you want to cut off the short-circuit current, you can use a fuse.

.

What are the basic requirements for an isolating switch：

(1) The isolating switch should have an obvious disconnect point to easily identify whether the electrical equipment is disconnected from the power supply;

(2) There is sufficient insulation distance between the disconnecting points of the isolating switch to ensure that when overvoltage and phase-to-phase flashover occur, breakdown will not occur and endanger the safety of workers;

(3) It should have sufficient short-circuit stability and cannot be automatically disconnected due to the action of electricity, otherwise it will cause serious accidents;

(4) It requires simple structure and reliable action;

(5) The main isolating switch and the grounding isolating switch must be interlocked to ensure the operation sequence of the grounding knife opening first and then closing; open the grounding knife first, and then close the isolating switch.