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:
Apr. 13, 1993
Filed:
Jan. 11, 1990
Tomio Yoshikawa, Shimizu, JP;
Takashi Kato, Shimizu, JP;
Tetsuji Yamashita, Shizuoka, JP;
Kyoshiro Murakami, Shimizu, JP;
Shizuo Zushi, Hadano, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A control system for controlling cooling equipment comprising a refrigerant circuit for cooling water by heat exchange, a plurality of cooling modules in a backup relationship with an adjusting apparatus for adjusting the cooling capability of the refrigerant circuit and a controller controlling the adjusting apparatus for adjusting the cooling capability, a control module having a coolant temperature sensor and a controller for calculating a cooling capability control command based on the value detected by the coolant temperature sensor. The controller in one of the cooling modules controls the adjusting apparatus and on the cooling capability control commend transmitted from the controller in the control module. Each of the cooling modules has a coolant temperature sensor for detecting the same coolant temperature as detected by the coolant temperature sensor of the control module so that, when an abnormality occurs in the coolant temperature sensor in the control module, the controller in the control module calculates the cooling capability control command based on the value detected by the coolant temperature sensor in the cooling module. The control system is therefore capable of performing a backup operation effective for the occurrence of an abnormality in the control module.