DDA-3000 and DDA-6000 Universal circuit breaker test sets
Fully digital initiating control circuit provides both pulsed and maintained control modes of output duration. The pulsed mode automatically pulses the output to any programmed pulse duration. This provides additional testing
capabilities for electromechanical and solid-state trip devices. A short pulse duration also limits the preheating of the breaker under test while setting the test current.
Use of digitally controlled SCRs instead of a contactor to initiate the output of the test set eliminates closing-time error and thereby ensures precise initiation at the zero crossover point of the output current waveform every time. Initiation at the zero crossover point ensures symmetrical output current by eliminating dc offset in the current waveform. Therefore accurate, repeatable test results are assured even with currents of very short duration, as when conducting tests of instantaneous or short-time delay trip elements.
Built for years of trouble-free, reliable operation, the test sets include rugged instrumentation and controls designed to withstand the vibration and shock of frequent transportation. They need never be removed from the enclosure. Ground safety interlock: An interlock circuit ensures that the test set chassis is connected to system ground before the output of the test set can be energized.
