Testing device for switching element tripping - has capacitor in parallel to DC voltage source, which can be additively coupled in series to source for testing

摘要

The tested switching element is used for the control of a series-connected processing device in such manner that is reacts to a voltage of a d.c. source, exceeding a preset limit value. The reaction takes the form of an interference indication. To the direct voltage source (GR) is connected in parallel a capacitor (K). During testing the latter can be additively series-connected to the voltage of the d.c. source via switching devices (SCH). In such instance the switching element (SG) can be tripped by the resulting voltage. Preferably a logic element (UI) blocks the effect of the switching element upon the processing device (U), on test tripping. A second logic element (U2) trips an interference indicator for the processing device, when during testing the switching element has not been tripped. The switching element may be in the form of a relay.