We will encounter some problems more or less when using frame circuit breakers. How to quickly identify the cause of the failure and quickly restore the normal power supply is very important in the power industry. Below we will summarize and analyze the common problems of frame circuit breakers, so as to facilitate the maintenance personnel to make quick judgments, reduce power supply failures, and ensure the safety of users' property.

circuit breaker tripped
Possible causes: overload fault tripping; short circuit fault tripping; ground fault tripping; undervoltage release tripping; mechanical interlocking action.

Approach:
Check the breaking current value and operating time on the circuit breaker intelligent controller; analyze the load and power grid operation; if the overload is confirmed, immediately find and eliminate the fault; if the actual operating current does not match the long-time delay operating current, please refer to the actual operating current Modify the long-delay action current setting value to properly match the protection;
Check the setting value of the intelligent controller; check whether the circuit breaker is in good condition, and determine whether it can be closed for operation;
Check whether there is a ground fault, please check whether the ground fault current setting value is appropriate and whether it matches the actual protection; if the setting is not suitable, the ground fault current setting value should be modified;
Check whether the power supply voltage is lower than 70% Us; check whether the undervoltage release and the control unit are faulty;
Check the working condition of two circuit breakers equipped with mechanical interlocks.

Circuit breaker does not close
Possible causes: The undervoltage release is not closed; the reset button is not reset; the drawer circuit breaker is not shaken in place; the secondary circuit of the drawer circuit breaker is not in good contact; the circuit breaker is not pre-charged; blocked; closing coil problem

How to deal with different problems:
Check whether the undervoltage release is powered on, check whether the undervoltage release and the control unit are faulty, if the fault is confirmed, replace the undervoltage release; if the reset button is not reset, press the reset button; Shake in place, locked in the "connection" or "test" position; check the contact of the secondary circuit and remove it; check whether the motor control power supply is connected and must be ¡Ý85% Us, and check whether the motor energy storage mechanism is faulty; check Check whether the mechanical interlocking state of each circuit breaker is normal; check that the power supply voltage of the closing coil must be ¡Ý85% Us. If there is a problem with the closing electromagnet, it should be replaced if it cannot be pulled in.