The CMD420/421 current monitoring devices monitor AC currents using three measuring inputs for overcurrent, undercurrent or undercurrent and overcurrent (window discriminator function). The currents are measured as r.m.s. values (AC). The currently measured values are continuously shown on the LC display. The respective measuring channel can be selected using the Arrow up or Arrow down button. The measured values causing the alarm relay to switch are stored. Due to adjustable delay times, installation-specific characteristics, such as devicespecific making currents, short-time current changes etc. can be considered
