Abstract: A UPS power distribution panel which includes means for detecting and differentiating between a symmetrical current waveform and a non-symmetrical current waveform and means for tripping and clearing a circuit breaker in the former but not the latter condition within one current waveform cycle.

Abstract: A pulse generator including a control logic operating, by control pulses, a switch connected on the input side with a voltage supply unit and delivering a pulse voltage on the output side, there is connected, between control logic and the switch, a capacitor, which decreases the pulse voltage when the pulse frequencies are too low, and, additionally, arranged between voltage supply unit and switch, an RC-member, which decreases the pulse voltages when the repetition rates of the control pulses are too high, in order to enable use of the pulse generator in the explosion-protected area.