Cause Analysis And Treatment Of Breaker Trip

Generally speaking, after the trip, the first thing to do is not immediately contact inspection or maintenance, but to determine whether it is a mistake trip. If there is no reason for the current and voltage fluctuations, it is likely to be a misoperation of the circuit breaker operating structure.
Once it is clear that the circuit breaker has indeed tripped, the cause should be identified. Generally speaking, there are two main causes of circuit breaker trip, the first type is short circuit. Such as in a humid environment is prone to similar situations. I remember that a customer reported that a DW16-2500 universal circuit breaker normally occurs in sunny days and often trips in rainy days, which is caused by short circuit. The final inspection is due to the control circuit short circuit, leading to binary wire burn caused tripping phenomenon.
The second type of cause is the load, for a simple example, if the line current is 200A, and the circuit breaker's frame current is only 100A, when connected to the motor, the line is normal, but for the circuit breaker has been significantly overloaded, which will cause the circuit breaker to trip all the time. About the load trip, the most common is in our daily life, the leakage circuit breaker (such as DZ47le-32 leakage circuit breaker) caused by too much current trip. Generally speaking, trip should not occur based on load. The rated current and other parameters of the line should be known when selecting the type. Here also add a little knowledge: if the circuit breaker at the start of the moment trip phenomenon, is caused by short circuit. The trip in the starting process is caused by overload.
After analyzing the two kinds of reasons of circuit breaker trip, summarize some common analysis and treatment methods. The first is to determine whether the fault is the line or the circuit breaker. The general process is as follows:
Observe whether the primary line is burnt, whether there is a peculiar smell, and whether the secondary control loop in the low-voltage cabinet is faulty
1. When there is a fault point, it indicates that it is a line problem and has nothing to do with the circuit breaker.
2. If there is no obvious fault point and the circuit breaker still cannot be closed without load, it indicates that the circuit breaker trip cannot be put into operation, which is the fault of the circuit breaker itself.
General line is easy to solve, and if it is a circuit breaker problem, further inspection is needed, possible reasons are: mechanical system failure, free trip wear, operating mechanism failure, etc. Here are two scenarios:
A. Ground fault trip (ground fault indicator is on) The solution is to check the breaking current value and operation time of the trip device. If it is confirmed that there is a ground fault, find and remove it immediately. If no grounding fault occurs, check whether the grounding fault current setting is appropriate. If not, change the grounding fault current setting.
B. Undervoltage trip and mechanical interlock The usual solution is to check whether the Ue of the power supply is lower than 70% and whether the undervoltage trip and control unit are faulty.
There are many reasons why the circuit breaker cannot close after tripping. For example, the circuit breaker cannot close because the undervoltage trip device is out of power and the voltage is too low or the undervoltage trip device coil is out of power, which will lead to the failure of re-closing. The topic of failure to close will be elaborated in a future article. Some of the suggestions in the article are just a summary of experience, and cannot solve all problems. If there is a problem, it is best to ask an experienced engineer to solve it or contact the corresponding manufacturer.