A high voltage tester, often referred to as a hipot tester or high potential tester, is typically not designed to directly measure the trip coil current of a high voltage circuit breaker. Instead, the trip coil current of a high voltage circuit breaker is typically measured using specialized test equipment designed specifically for circuit breaker testing, such as a circuit breaker analyzer or a secondary injection test set.

Here's a general overview of how the trip coil current of a high voltage circuit breaker is measured using specialized test equipment:

1. Preparation: Before conducting the test, ensure that the circuit breaker is properly isolated from the power source and de-energized to prevent any potential hazards.

2. Connection: Connect the test equipment to the trip coil terminals of the circuit breaker. The trip coil terminals are typically located on the circuit breaker mechanism and are connected to the trip coil, which is responsible for actuating the opening mechanism of the circuit breaker in response to a fault condition.

3. Test Setup: Configure the test equipment to inject a test current into the trip coil circuit. This test current simulates the current that would flow through the trip coil during an actual fault condition.

4. Injection of Test Current: Activate the test equipment to inject the test current into the trip coil circuit of the circuit breaker. The test current should be carefully controlled to ensure it does not exceed the rated capacity of the trip coil or cause any damage to the circuit breaker.

5. Measurement: During the injection of the test current, the test equipment measures and records the actual current flowing through the trip coil circuit. This measured current is the trip coil current of the circuit breaker.

6. Analysis: Once the measurement is complete, the test equipment may analyze the measured trip coil current to ensure it falls within the acceptable range specified by the manufacturer or industry standards. Any deviations from the expected values may indicate potential issues with the trip coil or the circuit breaker mechanism.

By measuring the trip coil current of a high voltage circuit breaker using specialized test equipment, maintenance personnel can verify the proper functioning of the circuit breaker's tripping mechanism and ensure its reliability and effectiveness in protecting the electrical system against faults.