The Model 421 detects an overload or under-load condition on all types of running motors; conveyor motors, elevator motors, mixer motors, submersible pumps, suction pumps, etc. The monitor detects the actual power used (voltage x current x power factor) and is more sensitive than simple current monitors. The Model 421 can be used with single-phase motors, or using the Model 276C Current Transducer, with three-phase motors. Matching CTs allow the Model 421 to be used with virtually any size of motor. Trip and restart delays are provided; one or both can be turned on or off.