Air conditioning load management control system

• US 5,293,755 A
• Filed: 12/09/1992
• Issued: 03/15/1994
• Est. Priority Date: 12/09/1992
• Status: Expired due to Fees

• Current Assignee: Charles V. Thomas
• Original Assignee: Charles V. Thomas
• Inventors: Thomas, Charles V.
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US07/987,776
• Time in Patent Office: 461 Days
• Field of Search: 307/39, 62/208, 236/91 D, 236/91 R
• US Class Current: 62/208
• CPC Class Codes: G05D 23/1923 using thermal energy, the cost of which varies in function of time

Abstract

A load management control system is provided for an air conditioner. The system includes an outdoor temperature sensor for sensing outdoor temperature of the outside of an enclosure to be air-conditioned and an indoor temperature sensor for sensing an indoor temperature of the enclosure. A device is provided for determining a difference in output of the indoor and outdoor temperature sensors. A device is provided for comparing the difference in output of the indoor and outdoor temperature sensors with a reference input. The system further includes a device for detecting an external controlling signal from an input device coupled to the system. A control device is provided for controlling an air conditioner control circuit based upon input from the comparing device and the detecting device. When an allowable temperature differential is exceeded, the controlling device opens at least one contact to interrupt the air conditioner control circuit so as to reduce electrical load. The controlling device closes the contact to restore the operation of the air conditioner control circuit when the temperature differential is no longer exceeded.

Claims

1. A load management control system for an air conditioner comprising:

an outdoor temperature sensor for sensing outdoor temperature of the outside of an enclosure to be air-conditioned;

an indoor temperature sensor for sensing an indoor temperature of the enclosure;

means for determining a difference in output of said indoor and outdoor temperature sensors;

means for comparing said difference in output of said indoor and outdoor temperature sensors with a reference input;

means for detecting an external controlling signal from an input device coupled to said system;

means for controlling an air conditioner control circuit based upon input from said comparing means and said detecting means, whereby, when an allowable temperature differential is exceeded while the external controlling signal is detected, said controlling means interrupts operation of said air conditioner control circuit so as to reduce electrical load, said controlling means restoring the operation of said air conditioner control circuit when said temperature differential is no longer exceeded.

2. A load management control system as claimed in claim 1, further comprising:

means for comparing said inside temperature to a preset limit to determine whether said inside temperature exceeds said preset limit; and

means for blocking control of said controlling means when said indoor temperature exceeds said preset limit.

3. A load management control system as claimed in claim 1, further comprising means for ramping inside temperature changes so as to not take place faster than a predetermined rate when a sudden drop in outside temperature occurs.

4. A load management control system as claimed in claim 1, wherein said external control device is a load management controller having a dry contact.

5. A load management control system as claimed in claim 1, wherein said external control device is a communications subsystem.

6. A load management control system as claimed in claim 1, wherein said determining means and said comparing means are each operational amplifiers analog circuits.

7. A load management control system as claimed in claim 1, wherein said controlling means controls an output relay, said relay being connected to said air conditioner control circuit.

8. A load management control system as claimed in claim 1, wherein said determining means, said comparing means, said detecting means and said controlling means is a microprocessor.

9. A method of controlling an air conditioning system comprising the steps of:

operating the air conditioning system at full load;

determining a temperature outside an enclosure to be air conditioned;

determining a temperature inside said enclosure;

determining the difference between said inside and outside temperatures;

interrupting a control circuit of a cooling device of said air conditioning system when said difference exceeds a predetermined differential so as to reduce electrical load; and

resuming operation of said cooling device at full load when said inside temperature rises to reduce the difference between said inside and outside temperature below said predetermined differential.

10. A method of controlling an air conditioning system as claimed in claim 9, wherein the steps of determining a difference between inside and outside temperatures, and interrupting and resuming the operation of said cooling device are is accomplished by an analog circuit.

11. A method of controlling an air conditioning system as claimed in claim 9, wherein the steps of determining a difference between inside and outside temperatures, and interrupting and resuming the operation of said cooling device are is accomplished by a digital circuit.

12. A method of controlling an air conditioning system comprising the steps of:

establishing an inside temperature set point;

operating the air conditioner at full load;

determining a temperature outside an enclosure to be air conditioned;

determining a temperature inside said enclosure;

determining the difference between said inside and outside temperatures;

interrupting a control circuit of a cooling device of said air conditioning system when said difference exceeds a predetermined differential so as to reduce electrical load; and

preventing said indoor temperature from exceeding a predetermined value greater than said inside temperature set point by cooling said enclosure while at a reduced load; and

resuming operation of said cooling device at full load when said inside temperature rises to reduce the difference between said inside and outside temperature below said predetermined differential.