Automatic circuit breaker tester UPA-3 is designed for testing and ampere-second characterization of automatic AC current circuit breakers. The device allows registering the value of the supplied current and timing the automatic circuit breaker switching interval. Circuit breaker tester UPA-3 is a mobile device, which could be easily transported to a required testing location. Circuit breaker tester UPA-3 operates on the principle of varying the power in the primary circuit of the matching power transformer and, respectively, varying the output current, flowing through the automatic circuit breaker under the test. Power regulation could be done either through an external regulator (RNO or VR) or through a built-in thyristor controller.
