Whirlpool Corporation
Heater status monitor

Abstract:

An appliance having a heater connectable to a power source to create a heater circuit is disclosed. The appliance includes a controller and a heater switch configured to be selectively closed in response to a control signal from the controller to complete the heater circuit and enable current to flow from the power source to the electric heater. The appliance further includes a heater feedback circuit comprising a plurality of resistors and configured to be connected to the power source and further configured to generate an output signal to the controller having a first state indicative of no current leakage from the heater circuit, a second state indicative of current leakage from the heater circuit where the polarity of the power source is normal, and a third state indicative of current leakage from the heater circuit where the polarity of the power source is reversed. The controller may determine whether current leakage exists in the heater circuit, regardless of the polarity of the grid lines from the power source. The controller may take various actions in response to such determination.