The self-calibrating switches use the actual load current to set the trip point and provide the simplest way to ensure that a motor is working properly. Because the current sensing Smart-Switches are self-powered and self-calibrating, they speed start-up and minimize installation costs. Three models are available to provide status monitoring, overload or underload, or operating window (overload and underload) functionality to suit particular pump, fan, heating element, conveyor or multi-load safety-interlocked application needs. The output contact is AC and DC compatible for use with any automation system.
The ASM sensor slides or snaps over one conductor feeding the load. The contact controls the input voltage, AC or DC, to 135 volts to a controller or small relay. It takes just seconds of steady running conditions before the sensor locks onto the normal current level. If the load draws more current than normal or the current drops significantly, the sensor output will open. If the current falls below 85% of normal or increases above 125% of normal the contact will open, with no manually setting trip points and no adjustments needed unless a motor is replaced. Should a motor be replaced calibration is very easy, and within a matter of minutes the system is back in operation.