Littelfuse 250-100-MET (Replaces METRON-100) Model 250-100/Right Form C RelayLittelfuse 250 100 MET Description: (Replaces METRON 100) Model 250 100 MET is a voltage monitor designed to protect 3 phase motors regardless of size. It is used on 95 120VAC, 50 60Hz motors to protect the motors from damage caused by low voltage, voltage unbalance, single phasing and reverse phasing. Littelfuse 250 100 MET Voltage Monitor Typical Applications Fans Compressors Air Conditioners Heat Pumps Well Pumps Sump Pumps Small Conveyor Motors