Littelfuse 460-100-SP Single-Phase Voltage MonitorLittelfuse 460 100 SP Voltage Monitor Product Descriptions The 460 100 SP is used on 95120 V ac, 50* 60 Hz single phase motors and the 460 200 SP is used on 190240 V ac, 50* 60 Hz single phase motors to protect them from damaging high and low voltage conditions. An adjustment knob allows the user to set a 1500 second restart delay. The variable restart delay is also a power up delay and can be utilized to stagger start motors on the same system. A