Patent ID: 8350405
Filing Date: 2013-01-08
Classification: G05B,H02J,Y02B,Y04S

Abstract:
1. A transfer switch apparatus for switchably supplying utility power from a utility power supply and standby electrical power from an electric generator to a load, wherein the load includes first and second thermostatically controlled central air conditioning units, comprising: a transfer switch having a utility electrical input connectable to the utility power supply and having a generator electrical input connectable to the electric generator, and further having an electrical output connectable to the first and second air conditioning units, and wherein the transfer switch is movable between a first position that allows utility power to be provided to the electrical output and a second position that allows standby electrical power to be provided to the electrical output; a first switch connectable to a first thermostat and the first central air conditioning unit and a second switch connectable to a second thermostat and the second central air conditioning unit, the first switch movable between a first position that prevents the first thermostat from thermostatically controlling the first air conditioner unit and a second position that allows the first thermostat to thermostatically control the first air conditioner unit, and the second switch movable between a first position that prevents the second thermostat from thermostatically controlling the second air conditioner unit and a second position that allows the second thermostat to thermostatically control the second air conditioner unit; and a control module communicatively connected to the first switch and the second switch, and configured to provide control signals to the first switch and the second switch to move the first and the second switches between the first and second positions to prevent overloading of the electric generator when the transfer switch is in the second position, the control module is operative in at least one of a plurality of operating modes, and wherein the plurality of operating modes includes: a first mode in which thermostatic control of the first air conditioner unit is only permitted, wherein the control module is caused to move the first switch to the second position to allow thermostatic control of the first air conditioner unit and is caused to move the second switch to the first position to prevent thermostat control of the second air conditioner unit, and wherein the second switch is kept in the first position until restoration of utility power at the utility power input; a second mode in which thermostatic control is permitted for the first and the second air conditioner units with priority given to the first air conditioner unit, wherein the control module is caused to move the first switch to the second position to allow thermostatic control of the first air conditioner unit and is caused to move the second switch to the first position to prevent thermostatic control of the second air conditioner unit and is further caused to maintain the second switch in the first position if the first air conditioner unit is supplying conditioned air but move the second switch to the second position to allow thermostatic control of the second air conditioner if the first air conditioner is not supplying conditioned air, and wherein the control module is first caused to move the first switch from the second position to the first position before moving the second switch from the first position to the second position to prevent simultaneously thermostatic control of the first and the second air conditioner units; a third mode in which conditional simultaneous thermostatic control of the first and the second air conditioner units is permitted, wherein the control module is caused to move the first switch to the second position to allow thermostatic control of the first air conditioner unit and is caused to move the second switch to the first position to prevent thermostatic control of the second air conditioner unit and is further caused to maintain the second switch in the first position if the first air conditioner unit is supplying conditioned air but move the second switch to the second position to allow thermostatic control of the second air conditioner if the first air conditioner is not supplying conditioned air or a preset delay time has expired, wherein the third mode permits simultaneous thermostatic control of the first and the second air conditioner units after expiration of the preset delay time; and a fourth mode in which alternating thermostatic control of the first and the second air conditioner units is provided, wherein the control module is caused to move the first switch to the second position to allow thermostatic control of the first air conditioner unit for a first preset period of time and is caused to move the second switch to the first position to prevent thermostatic control of the second air conditioner unit for the first preset period of time, and wherein the control module is further caused to move the first switch to the first position to prevent thermostatic control of the first air conditioner unit upon expiration of the first preset period of time and for a second preset period of time and is caused to move the second switch to the second position to permit thermostatic control of the second air conditioner unit upon expiration of the first preset period of time and for the second preset period of time.