Of control electric circuit of circuit breaker switch, if used air as extinguishing medium air circuit breaker (switch), arc-quenching media SF6 gas called sulfur hexafluoride circuit breaker (switch). Circuit breakers with rated current (load), and used for electrical circuit switch. Circuit breaker is a switch, it and other regular switch points: 1. Application of high voltage; 2. Extinguishing medium and method, vacuum, oil, oil and sulphur hexafluoride etc; 3. ARC-quenching ability, good effect.
Main functions of the circuit breaker: 1. Normally connect and disconnect the high voltage circuits, no-load and load current; 2. If the system fails to dovetail with protection device and automatic device, quickly cut off the fault current and prevent accidents expanded, so as to ensure safe operation of the system.
General circuit breaker itself there is no lubrication problems, require lubrication often is the actuator. Effect of the thermal relay is cut off power supply automatically when the motor load, thermal relay structures are two different expansion coefficients of the metal sheet, excessive current, expansion coefficient of expansion, to cut off the power supply. After the thermal relay with manual reset and auto reset. FUSE: when a fault or exception occurs when the circuit, along with the rising currents, and high currents can damage the circuits of some important or valuable devices may also be burnt circuit or even fire. If fuse is placed correctly in the circuit, then in abnormally high current fuses to a certain height and a certain amount of time, their fusing shut off the current, and thus play a role in the safe operation of protection circuits. If the circuit breaker is installed must not have fuses, thermal relays need to be used with AC contactor, overload thermal relay contact on disconnect cut off the control circuit, fuses for control circuit more commonly now.