The mV trip relays will accept DC Millivolts signals from shunts, sensors and transducers A common application is to protect equipment from over current in a DC charging system. For example using a 400A to 75mV shunt. The 75mV signal is fed to the M200-MVO if the customer wishes to ensure the current does not exceed 300 amps then the MVO trip would be set at 75 % (56.25mv). If the current goes above 300 Amps the relay would energize.As is common with all the M200 relays, on over units the relay energizes when the input signal exceeds the trip point and on under units the relay de-energizes when the input signal goes below the trip point. A red LED indicates the state of the relay, whilst a green LED indicates the condition of the power supply.