The high current generator measures the role of the circuit breaker in the circuit resistance.

Many high-current electrical equipment in the power system needs to accurately measure the resistance value of the loop in the preventive test and handover test. The circuit breaker is an important electrical equipment in the power system. The national standard GB763, GB50150 and the power industry standard DL/T596 all stipulate the measurement of the circuit resistance of the circuit breaker: it should be measured by the DC voltage drop method, and the current should not be less than 100A. The resistance of the conductive circuit of the circuit breaker mainly depends on the contact resistance between the moving and static contacts of the circuit breaker.

The existence of the contact resistance of the high-current generator increases the loss of the conductor when it is energized, which increases the temperature of the contact. . Therefore, the resistance value of the conductive circuit of each phase of the circuit breaker is an important data for the installation, maintenance and quality acceptance of the circuit breaker.

In the past, the contact resistance of circuit breakers was usually measured with a DC double-arm bridge. However, when the double-arm bridge is used to measure the resistance of the circuit breaker's conductive circuit, since the double-arm bridge measurement loop passes through a weak current, it is difficult to eliminate the oxide film with large resistance, and the measured resistance indication value is too large. However, the oxide film is easily broken down under a large current, which does not prevent the passage of normal current. Therefore, when the test adopts the DC voltage drop method, the current should not be too small.