Patent RE40499 was granted and assigned to Carrier Corporation on September, 2008 by the United States Patent and Trademark Office.
Step control in capacity modulation of a refrigeration or air conditioning circuit is achieved by rapidly cycling a solenoid valve in the suction line, economizer circuit or in a bypass with the percent of “open” time for the valve regulating the rate of flow therethrough. A common port in the compressor is used for economizer flow and for bypass.