T & R 100ADM F Filter Unit

The 100ADM F Filter Unit reduces the level of current harmonics when testing electro mechanical protection relays It is designed for use with our range of secondary injection test sets

All electro mechanical protection relays have iron cores that saturate and distort the test current under high overload test conditions The distortion causes significant errors in the measured trip time of these relays during testing Distortion of the waveform can be a particular problem with disc induction type over current and sensitive earth fault relays

For example testing a CDG11 disc induction over current relay without a filter causes significant timing errors The results bellow show the errors for a 1 3s 1A CDG11 over current relay on its 0 5A plug setting tested at 5A