The 84872141 is a DIN rail-mounted Voltage Monitoring Relay with a single-pole double-throw (SPDT) contact configuration. This versatile monitoring relay belongs to the MUS/MUSF series and features over-voltage and under-voltage control functions, a selectable latching (memory) feature, adjustable time delays, and LED indicators for status monitoring. It includes a green LED display indicating power supply status, with a maximum measurement cycle time of 250ms using True RMS measurement. The relay provides a display precision of ±10% of full scale, a reset time of 1.5 seconds, and a repetition accuracy within ±0.5%. It requires a minimum breaking current of 10mA at 5V DC and has an AC breaking capacity of 1250VA (resistive load). The device supports up to 360 operations per hour at full load, withstands rated impulse voltages of 4kV (1.2/50µs), and insulation withstand voltage of 2kV AC at 50Hz for 1 minute. Its insulation resistance exceeds 500 MΩ at 500VDC, with a mechanical life of over 30 million operations and an electrical life of 10 million operations. Suitable for industrial applications.