- Three Phase AC Systems

The VME420 is a powerful, all-in-one unit for measuring voltage and frequency in single-phase AC and DC systems. Two separate alarms allow for the simultaneous measurement of overvoltage, undervoltage, overfrequency, or underfrequency in systems up to 300 V AC/DC and AC systems from 15 to 460 Hz.

Measurements taken are read as true RMS values; harmonics up to 460 Hz are taken into account. Each of the two alarms has a seperate Form C SPDT contact for use with external alarm indicators and interrupters. The two alarms may be set to any combination of voltage and/or frequency readings. Contacts may be set for normally energized or de-energized operation.

The VME420 has three seperate, adjustable time delays (start-up, response, on release) from 0 to 99 seconds. Setpoint and hysteresis ranges allow for application-tailored sensitivity. A fault memory toggle allows alarms to either latch or auto-reset after it has cleared.

Values are read and settings are changed via a digital LCD display. Three pushbuttons allow for navigation through built-in menus. History memory stores the last received alarm. A password protection may also be set. The VME420 is a UL listed product.

These devices are suited for installation into standard distribution panels according to DIN 43 871 and for quick assembly onto support rail according to DIN EN 50 022 or for screw mounting.