The current being monitored is applied to the terminals B1 or B2 or B3 and C. The output relay energizes when the monitored current exceeds the set point. It de-energizes when the current is below the set point within the hysteresis range. Both current monitors are used to monitor overcurrents, the CM-SRN type in AC/DC supply version has a selection switch to select over or undercurrent function. Hysteresis is adjustable from 5-30 % related to the response value. Measuring, output and supply circuits are electrically isolated to prevent interference. As one measuring cycle takes only 80 ms, changes in current can quickly be detected.

User Manual:

Schneider Electric_Harmony-Control-Relays_RM4UA33MW