Time Mark 20VB

3-Phase Voltage Band Monitor with Trip and Restart Delays, 3PH,190-480V 50/60 Hz,SPDT, cUL/UL

3Ph/Adj/Hv/Lv/Time Delay/Restart

A microcontroller-based universal 3-phase voltage band monitor for protecting 3-phase motors of any size from abnormal power conditions. This unit is UL Recognized in the U.S. and Canada and can detect under voltage, over voltage, voltage unbalance, reverse phase, and single-phasing even when regenerated voltage is present. Status of the 3-phase system is indicated by LEDs. Relay operation is fail-safe, i.e. the SPDT output contacts drop out when a fault condition or loss of power occurs. Under and over voltage trip points are both adjustable. The under voltage adjustment has two scales, 185-240VAC and 370-480VAC. The over voltage adjustment also has two scales, 208-264VAC and 416-528VAC and it will auto-range to the appropriate scale. A trip delay adjustment for preventing nuisance tripping during power fluctuations and a restart delay adjustment for preventing short cycling in compressor applications have also been provided. Voltage unbalance trip point is fixed at 6 percent. A neutral connection is not required and it can be used on either Wye or Delta systems. Operating power is drawn from phases A and B.