Series: HLVA

The HLVA (HLV) series is a single-phase undervoltage monitor designed to protect sensitive equipment from brownout or undervoltage conditions. Time delays are included to prevent nuisance tripping and short cycling. The 30 A, 1hp-rated, SPDT relay contacts allow direct control of motors, solenoids, and valves. The output relay can be ordered with isolated SPDT contacts to allow monitoring of one voltage and switching to a separate voltage. Two undervoltage trip point ranges allow monitoring of 110–120 V ac or 208–240 V ac systems.

Operation

Upon application of input voltage, the output relay remains de-energized. When the input voltage value is above the pull-in voltage, the restart delay begins. At the end of the restart delay, the output relay energizes. When the input voltage falls below the trip point, the trip delay begins. If the input voltage remains below the pull-in voltage for the entire trip delay, the relay deenergizes. If the input voltage returns to a value above the pull-in voltage during the trip delay, the trip delay is reset and the relay remains energized. If the input voltage falls below the trip point voltage during the restart delay, the delay is reset and the relay remains de-energized. Reset is automatic upon correction of an undervoltage fault.

Reset

Removing the input voltage resets the output relay and the time delays.