This product is no longer listed

Contact Resistance Tester

Contact Resistance Tester

Nowadays Power Systems widely use model QJ44 DC double arm bridge to measure contact resistance (DC resistance and Loop resistance of high-voltage circuit breaker) while the minimum current of such model is 1mA which hardly find the decrease of cross-sectional area of transformers' conductive circuit conductor. The measurement of loop resistance of high voltage switchgear is affected by oil layer and oxide between static and dynamic contact port, so the resistance measurement value will be several times larger, and can not reflect the true value of contact resistance. Therefore, the Ministry of Electric Power in national standards SD301-88 "AC 500KV Electrical Equipment Transfer and Preventive Test Procedure" and new version of " Electrical Equipment Preventive Test Procedure" stipulate that the testing current of circuit breaker and isolating switch contact resistance is not less than 100A to ensure accurate test results.

Get Help