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:
Jul. 05, 1977
Filed:
Mar. 12, 1976
Carl R Merola, Monroeville Borough, PA (US);
William F Evans, Penn Township, Westmoreland County, PA (US);
Raymond E Shaffer, Hempfield Township, Westmoreland County, PA (US);
Westinghouse Electric Corporation, Pittsburgh, PA (US);
Abstract
The heat pump system includes a first and a second centrifugal compressor arranged in series relation in a system including interstage expansion of the refrigerant. A pair of parallel circuits is provided for controlling the energization of the compressors in a sequence in which the first to start compressor must be energized to obtain completion of the second parallel circuit required for energization of the second to start compressor. The start of the second compressor is delayed for a period permitting the first compressor to come up to speed and the first circuit controlling the energization of the first compressor will be interrupted unless the second compressor has started within a short period of time after the time delay in starting the second compressor. The arrangement also includes a thermostatic switch in the first circuit and a relay arrangement controlled in accordance with the thermostatic switch for opening a part of the second circuit in accordance with the opening of the first circuit with the thermostatic switch. With this arrangement, a third, manual-reset circuit which must remain in a completed condition for normal operation of the compressors in accordance with temperature demands, is prevented from being interrupted by operation of a time delay opened switch in the manual-reset circuit under the control of a safety timing means in a branch circuit of the second circuit.