No.1

The symbol for the isolating switch is QS and the symbol for the circuit breaker is QF. In terms of function and structure, the main differences between isolating switches and circuit breakers are as follows:

1. Function: The circuit breaker has an arc extinguishing device and can operate with load, including load current and fault current; the isolating switch does not have an arc extinguishing device and is usually used to isolate the power supply and cannot be used to cut off or put in load currents and faults above a certain capacity. current.

2. Structure: The structure of the circuit breaker is relatively complex, usually composed of contacts, operating mechanism, tripping device, etc.; the structure of the isolation switch is relatively simple, mainly composed of a knife switch and an operating mechanism.

No.2 

In terms of usage occasions and operation methods, the main differences between isolating switches and circuit breakers are as follows:

1. Usage occasions: Circuit breakers are usually used in high-voltage power systems, such as substations, transmission lines, etc.; isolation switches are usually used in low-voltage power systems, such as distribution boxes, switch cabinets, etc.

2. Operation mode: Most circuit breakers are operated by remote electric control; most isolating switches are operated by local manual operation. To sum up, the circuit breaker is more powerful in function and can provide overload protection and short-circuit protection, while the isolating switch is mainly used to isolate the power supply to ensure safety during inspection, maintenance or other operations.