What is the function of circuit breaker, the working principle of circuit breaker is detailed explanation
When the system fails, the protection action of the fault element and the circuit breaker operation failure refuses to trip, trip the adjacent circuit breaker of the substation through the protection of the fault element, and the channel can also be used to make the wiring of the distal circuit breaker trip at the same time is called the circuit breaker failure protection.
Generally, after the action of the phase current components, the two groups of starting contact points are output, and the external action protection contact points are connected in series in the circuit, bus link or segment circuit breaker failure to start failure protection.
What are the functions of the circuit breakers
Circuit breakers are mainly used in frequent motors and large capacity transformers and substations. Circuit breaker has the function of dividing the accident load, and cooperates with various relay protection to protect the electrical equipment or lines.
Circuit breaker is generally used in low-voltage lighting, power part, can play the role of automatically cut off the circuit; circuit breaker and overload and short circuit protection and many other functions, but the lower load problem needs to be repaired is the disconnecting switch plays an electrical isolation role, and the circuit breaker creepage distance is not enough.
Now there is a circuit breaker with isolation function, which is the ordinary circuit breaker and disconnector function two in one. The circuit breaker with the isolation function can also be a body disconnector. In fact, the disconnector switch is generally not operated with load, while the circuit breaker has short circuit, overload protection, underpressure and other protection functions.
Working principle of circuit breaker is detail
Basic type: The simplest circuit protection device is the fuse. The fuse is just a very thin wire, with a protective case and then connected to the circuit. After the circuit is closed, all currents must flow through the current at the fuse —— fuse as the same current at other points on the same circuit. The fuse is designed so that it can fuse when the temperature reaches a certain level. Burrowing the fuse can cause open roads to prevent excessive current from damaging the house wiring. The problem with the fuse is that it can only work once. Whenever the fuse is burned off, it must be replaced. Circuit breakers can do the same role as fuses, but they can be used repeatedly. As soon as the current reaches a dangerous level, it immediately causes an open circuit.
Basic working principle: the fire wire in the circuit is connected to both ends of the switch. When the switch is placed in the on state, the current flows out from the bottom terminal, successively through the electromagnetic body, mobile contacts, static contacts, and finally from the top terminal. The current can magnetize an electromagnetic magnet. The magnetic force produced by the electromagnetic magnet increases with the current, and if the current decreases. When the current jumps to a dangerous level, the EM experience produces a large enough magnetic force to pull a metal rod connected to the switch linkage. This causes the moving contactor to tilt and leave the static contactor, then cutting off the circuit. The electric current is also interrupted. The bimetal bar is designed based on the same principle, the difference is that there is no need to give the electromagnetic body energy here, but allows the metal bar to bend at a high current, and then start the linkage device. Some circuit breakers also fill in explosives to move the switch. When the current exceeds a certain level, it ignites the explosive material and then drives the piston to open the switch
Enhanced models: More advanced circuit breakers abandon simple electrical equipment and instead use electronic devices (semiconductor devices) to monitor current levels. Ground fault circuit breaker (GFCI) is a new type of circuit breaker. This circuit breaker can not only prevent damage to the house wiring, but also protect people from electric shocks.
Enhanced work: The GFCI constantly monitors the current on the zero and fire lines in the circuit. When everything is normal, the current on both lines should be exactly the same. Once the fire line is directly grounded (for example, someone accidentally touches the fire line), the current on the fire line suddenly increases, while the zero line does not. The GFCI cuts off the circuit immediately after detecting this condition to prevent electric shock casualties. Because the GFCI can take action without waiting until the current rises to a dangerous level, it reacts much faster than conventional circuit breakers.
Post time: Aug-24-2022
