Description

It detects the presence of harmonics in the circuit that it is being measured and it trips when they exceed a threshold that can be adjusted by the user. It receives the signal from a current transformer. Some models have the trans-former incorporated in the same relay, while for currents higher than 200 A, the signal has to be provided externally. In power capacitors, it is used to disconnect them in the case that the harmonic level exceeds an established threshold, avoiding in this way them damage due to over currents. They incorporate a trip delay adjustment and a threshold selection adjustment. Output is made by one change-over contact.