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:
Feb. 08, 1994
Filed:
Feb. 25, 1993
Jay L Hanson, Bloomington, MN (US);
Gerald J Ladendorf, Bloomington, MN (US);
Doyle G Herrig, Elko, MN (US);
Thermo King Corporation, Minneapolis, MN (US);
Abstract
A method of monitoring a refrigeration unit including detecting premature return of air discharged into a conditioned space, and distinguishing this 'short cycling' problem from a refrigeration capacity problem. The method includes determining the rates of change of the temperatures DA and RA of the discharge air and return air, respectively, during temperature pull down of the conditioned space, and comparing the rates of change with predetermined constants selected to detect a short cycling of the discharge air. When the rates of change do not fit a normal temperature pull down, the differential .DELTA.D between the temperatures DA and RA of the discharge air and return air is determined and compared with a third constant. Predetermined results of the comparisons of the rates of changes of DA and RA, and the temperature difference .DELTA.D with the first, second and third constants, respectively, are utilized to identify proper air flow in conditioned space, to indicate a problem with air flow in conditioned space, and to indicate that refrigeration capacity should be checked.