Circuit breakers can go bad after a while of operation. The contacts are often subjected to high currents, transients and sometimes inductive kickbacks. It is a good idea to constantly assess the reliability of your circuit breakers to ensure safe operation. You don’t want a faulty circuit breaker to be the cause of electrical system failure.
Measuring contact resistance is one of the tests conducted on circuit breakers. This test is conducted using a DLRO. Contact resistance gives you an idea of the condition and reliability of the circuit breaker. The electrical stress can increase the resistance of the contacts after a while. The increase in resistance can cause problems like localized heating and eventual welding of the contacts. The welding of the contacts can be dangerous because the breaker will not trip if the electrical system goes into overload.
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