The thermal tripping mechanism disconnects the circuit breaker when its rated current is exceeded for a predetermined period of time. This tripping mechanism allows for short-duration overcurrent conditions, which are common in some applications; for example, electric motors may draw 5 to 8 times their rated current when they start, but only for a very short time.
On the other hand, the magnetic tripping mechanism has an instant response and is designed to clear high-current faults such as short circuits or ground faults. When these faults occur, they are always an issue and must be cleared as soon as possible. When you see circuit breakers labeled as type B, C or D, the letters indicate the threshold at which the magnetic tripping mechanism is activated.
Thus, if a circuit breaker trips, there are two main possibilities: either a fault has occurred, or the circuit breaker is not adequate for the application at hand. This article will provide an overview of the main reasons why circuit breakers trip.
Here are the five reasons. Click on the links to get the details!
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