UNITARY CONTROL FOR AIR CONDITIONER AND/OR HEAT PUMP

• US 20090049847A1
• Filed: 11/04/2008
• Published: 02/26/2009
• Est. Priority Date: 07/25/2003
• Status: Active Grant

• Current Assignee: Emerson Electric Company
• Original Assignee: Emerson Electric Company
• Inventors: Butler, William P., Jayanth, Nagaraj B., Drake, Dean A.
• Granted Patent: US 7,694,525 B2
• Time in Patent Office: Days
• US Class Current: 62/129
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 11/83 by controlling the supply of heat-exchange fluids to heat-exchangers
• CPC Class Codes: F24F 11/84 using valves

Abstract

A unitary control for operating at least the fan and compressor of a climate control apparatus in response to signals received from a thermostat, the unitary air conditioning control includes a circuit board, a microprocessor on the circuit board; a first relay on the circuit board operable by the microprocessor, to connect a fan connected thereto to line voltage, and having first and second contacts at least one of which is connected to the microprocessor; and a second relay on the circuit board operable by the microprocessor, to connect a fan connected thereto to line voltage, and having first and second contacts connected to the microprocessor.

Claims

1. A control system for operating at least the condenser fan and compressor of a climate control apparatus, the control system comprising:

a set of contacts for connecting power to a compressor motor;

a set of contacts for connecting power to a condenser fan motor;

at least one sensor for sensing a current level of the power connected to the compressor motor; and

a microprocessor in communication with the at least one sensor, the microprocessor being configured to generate a signal to close the contacts for connecting power to the compressor motor when a thermostat requests operation of the compressor, wherein the microprocessor responds to a sensed current level that is below a minimum threshold by generating a signal to open the contacts for disconnecting power to the compressor motor;

wherein the microprocessor is further configured to generate a signal to open the contacts for disconnecting power to the compressor motor when the thermostat requests discontinued operation of the compressor, where upon requesting discontinued operation of the compressor the microprocessor responds to a sensed current level indicating that the contacts are not open by initiating a response action.

2. The control system of claim 1 wherein the response action includes generating a first signal to close the contacts and generating a second signal to open the contacts for connecting power to the compressor motor.

3. The control system of claim 2 wherein the microprocessor repeatedly generates the first signal to close the contacts and second signal to open the contacts, to cause the contacts for connecting power to the compressor motor to switch to an open condition.

4. The control system of claim 1 wherein the response action includes communicating information relating to the contacts failing to open to the thermostat.

5. The control system of claim 1, wherein the at least one sensor comprises a sensor for sensing current through the contacts that is in connection with the microprocessor, wherein the current sensor senses the level of the current through the contacts for connecting power to the compressor motor.

6. The control system of claim 5, wherein the microprocessor discontinues compressor operation upon detecting a current through the contacts connecting power to the compressor motor that is indicative of a locked rotor.

7. The control system of claim 5, wherein when the microprocessor has generated a signal to close the contacts to connect power to the compressor motor, the microprocessor discontinues compressor operation upon detecting a current through the contacts connecting power to the compressor motor that is below a minimum threshold.

8. The control system of claim 7, wherein the current that is below a minimum threshold is a current level indicative of a motor winding failure.

9. The control system of claim 7, wherein the current that is below a minimum threshold is a current level indicative of a lack of refrigerant charge.

10. The control system of claim 7, wherein the microprocessor initiates a response action of sending a fault signal to a thermostat.

11. The control system of claim 2, wherein the microprocessor further generates a signal to close the contacts for connecting power to the condenser fan motor.