low voltage circuit breaker, also known as air circuit breaker. mainly used for automatic disconnection circuit and power cut-off under abnormal circumstances such as overload, short circuit and under-voltage. in the process of using air circuit breaker, we often encounter some problems. here we introduce the common faults and solutions of low voltage circuit breaker. the failure of
1 can not be closed

is caused by no voltage of under-voltage tripper or damage of coil, excessive spring force of reaction force, or failure of mechanism reset, etc. the method of repair is to check the voltage of the power supply, change the coil or readjust the spring. for the case that the mechanism can not be reset, it should be adjusted to the stipulation at the buckle contact surface.
{span 0} 2 circuit breaker temperature is too high  
          may be due to the decrease of contact pressure, at this time contact pressure can be adjusted or spring can be replaced. it may also be caused by severe contact wear or poor contact. at this time, new circuit breakers should be replaced. it is also possible to loosen the connection screw for two parts to the store and tighten it again.
{span 0} 3. when the circuit breaker fails to break normally,  
          check whether the bimetal sheet of the thermal release is damaged or not, and if damaged, replace it immediately. then check whether the distance between armature and core is too large or whether the coil is damaged, so as to adjust the distance between armature and core or replace the circuit breaker.
{span 0} 4. noise  
          appears to observe whether there is rust or oil stain on the surface of iron core, and if there is any, erase immediately. to observe whether the short circuit ring is broken, the armature and core should be replaced. we can see if the spring force of rice grain is too large. if it is too large, we should readjust

.