Voltage Monitor Relays

Voltage band relays monitor for over and under voltage conditions simultaneously energizing the output relay only when the voltage is within the proper "band" or range of voltage set using the adjustment dials on the relay. Contrast this to voltage "over/under" relays that simply energize the relay output when voltage is above the dial setting threshold.

Voltage Monitor Relays monitor either AC single phase (50-60Hz) or DC voltages to protect equipment for undervoltage and overvoltage fault conditions. The relays can be used as either overvoltage or undervoltage relays, depending on the output contact used. Overvoltage models provide protection to equipment that cannot handle excess voltages. Undervoltage relays provide protection to equipment that is required to operate above a certain minimum voltage. Voltage Band Relays provide protection to equipment that is required to operate within an upper and lower voltage limit. As long as the operating voltage remains within an OVER & UNDER voltage range, the internal relay stays energized. If the operating voltage falls outside this range, the relay will drop-out.

Macromatic relays specify the power consumed by the device as “burden” in units of VA. Look for the burden specification in the catalog page for the specific device you have. The unit of VA(volt-amps) is essentially the same as Watts(power), current draw can be calculated in Amps by taking the VA specification and dividing by the voltage control voltage you are using to power the device.

Macromatic maintains an extensive cross reference database. Follow the link here.