The Vishay AR3PJ-M3/86A is a panel-mount, three-phase AC voltage monitoring relay that provides real-time, three-phase voltage monitoring. It can monitor the voltage levels of each designated phase and, when the voltage exceeds or varies outside a predetermined range, it is set up to signal an alarm or trip a circuit breaker or other type of device. The maximum operating voltage range is from 0 to 600 V and the monitoring voltage ranges are selectable from 100 V to 1000 V. The nominal frequency can be either 50 Hz or 60 Hz, and the frequency response range is 0.45 Hz to 800 Hz. The device also features an adjustable voltage threshold and adjustable time delay, which can protect against short duration power transients, as well as a 24-bit microprocessor that supports a wide range of communication protocols and diagnostic capabilities.