The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 27, 2001
Filed:
Mar. 31, 2000
Raynald C. Clarke, Lithonia, GA (US);
David R. Cornish, Lithonia, GA (US);
Heatcraft Inc., Grenada, MS (US);
Abstract
In a space cooling system having an evaporator in heat exchange relationship with a space to be cooled, a condenser external to the space, a compressor for circulating heat transfer fluid between the evaporator and condenser, an expansion valve for controlling the flow rate of heat transfer fluid through the evaporator, apparatus for automatically closing the expansion valve in response to a loss of electrical power to the system. The apparatus includes a storage capacitor for storing electrical energy when power is being supplied to the system, a voltage detector for detecting a loss of electrical power and a controller for controlling a step motor to close the expansion valve in response to a loss of system power. The capacitor automatically discharges in response to a power loss condition to supply power to the controller and step motor to enable the expansion valve to be closed. Therefore, refrigerant migration in the system, which can damage the compressor upon restart, is substantially inhibited.