KRM72x monitors three phase AC supplies for incorrect phase sequence, phase failure and phase imbalance on systems up to 500V.
Operation
A sensitivity adjustment on the top of the unit allows adjustment up to 50% of the phase to phase voltage. The minimum level is selected to avoid any nuisance tripping due to normal variations in voltages.
A factory set delay of approximately two seconds prevents tripping due to transients. The unit is factory set for 50Hz or 60Hz. It is available as a 50/60Hz variation with associated loss of sensitivity.