Time Mark 272-24

3 Phase Monitor Current Unbalance

The Model 272 3-Phase Current Unbalance Detector monitors 3-phase lines to detect an unbalanced current. It can also monitor three separate single phase lines for equal current levels. The percentage of unbalance is adjusted from 2 percent to 25 percent by adjusting a front panel control. An unbalance greater than this setting energizes the relay. An adjustable trip delay of 0.5 to 10 seconds is also provided. For optimum performance, operating currents should be kept in the 1 to 5 amps range. However, zero current on each phase is considered to be a balanced condition. Continuous currents, up to 10 amps per phase, will not damage the unit, nor will current surges up to 40 amps for 2 seconds. The contacts are automatically reset when the unbalanced condition is corrected.