COMBINED TESTING APPARATUS FOR CIRCUIT BREAKER

PURPOSE:To complete testing at one time while impressing a transient recovery voltage of the 4 parameter standard and an alternating current by providing a second voltage source circuit which impresses a second transient recovery voltage and an alternating current voltage. CONSTITUTION:A primary input is impressed to a boosting transformer from a connecting line between a supply switch 5 of a current source circuit 1 and an auxiliary circuit breaker 6. A boosted secondary voltage is impressed to a capacitor 16 for adjusting the transient recovery voltage of a second voltage source circuit 20 and to a resistance 17, so that a vibrating voltage is generated. This voltage is supplied to a testing circuit breaker 7 through a current restricting resistance 18. A separating switch 19 is provided between a voltage source circuit 8 and the testing circuit breaker 7, so that the voltage source circuit 8 is separable from the circuit breaker 7. After the separation, a voltage is impressed to the circuit breaker 7 from the second voltage source circuit 20. Moreover, the voltage is the same alternating current voltage as that - that of the actual system. Accordingly, the transient recovery voltage of the four parameter standard and the alternating current voltage can be impressed by one testing operation.