Patent ID: 8328110

Claim:
An electronic control system for multiple air conditioning units, comprising: an enclosure; an electronic circuit board within the enclosure, the electronic circuit board having a first input terminal that receives a first thermostat control signal from a first thermostat intended to control a first air conditioning unit and a second input terminal that receives a second thermostat control signal from a second thermostat intended to control a second air conditioning unit, the electronic circuit board further including a first output terminal coupled to the first air conditioning unit and a second output terminal coupled to the second air conditioning unit; and a controller, on the electronic circuit board, programmed with instructions stored in a memory coupled to the controller, the instructions causing the controller to monitor the first and second input terminals to apply a load spreading algorithm that determines the timing and duration of the thermostat control signals passed to the output terminals for activating or deactivating the air conditioning units such that overlapping operation of the air conditioning units is reduced; wherein the load spreading algorithm prevents both air conditioning units from operating simultaneously for a predetermined period of time to reduce electrical demand on a utility grid to which the air conditioning units are connected, or wherein the load spreading algorithm permits both air conditioning units to operate simultaneously for a predetermined period of time when the algorithm determines, based on the input terminals, that a cooling demand cannot be satisfied with one of the air conditioning units deactivated.