The CME420 series current relays provide comprehensive current monitoring in AC systems, including undercurrent, overcurrent, and a window discriminator function that monitors current between two threshold values. These current measurements are based on r.m.s. values (AC) and are continuously displayed on the LC screen. The alarm relay is triggered when the measured value matches the preset threshold, and adjustable delay times allow for customization to account for installation-specific characteristics, such as device-specific making currents and short-time current changes. Current measurement is supported directly or indirectly through standard current transformers (x/5 A), and an external power supply is required.
