The test items for vacuum circuit breakers should include the following:
1) Measure insulation resistance;
2) Measure the resistance of each phase conductive circuit;
3) AC withstand voltage test;
4) Measure the opening and closing time of the main contact of the circuit breaker, measure the periodicity of opening and closing, and measure the bouncing time of the contact when closing;
5) Measure the insulation resistance and DC resistance of the opening and closing coil and the closing contactor coil;
6) Test of circuit breaker operating mechanism.
Measure insulation resistance value
1) The measurement of overall insulation resistance value should refer to the manufacturer's regulations;
2) The insulation resistance value of the insulation rod should not be lower than the specified value in the table at room temperature.
The resistance value of each phase conductive circuit should be measured using a DC voltage drop method with a current of not less than 100A. The test results should comply with the provisions of the product technical conditions.
AC withstand voltage test should be conducted in the closed and open states of the circuit breaker. When conducted in the closed state, the test voltage should comply with the provisions in the table. When conducting in the open state, the test voltage between the vacuum arc extinguishing chamber fractures should be in accordance with the product technical conditions, and there should be no through discharge during the test.
Measure the opening and closing time of the main contact of the circuit breaker, measure the periodicity of opening and closing, and measure the bouncing time of the contact after contact during the closing process, which should comply with the following regulations:
1) The bounce time after contact during the closing process should not exceed 2ms for circuit breakers below 40.5kV. 40.5kV and above circuit breakers should not exceed 3ms;
2) The measurement should be carried out under the rated operating voltage and hydraulic conditions of the circuit breaker;
3) The measured values should comply with the technical specifications of the product.
Measure the insulation resistance value of the opening and closing coils and the closing contactor coils, which should not be less than 10M Ω; There should be no significant difference between the DC resistance value and the product's factory test value.