Parallel Condensing Unit Control System And Method

Abstract

A method comprises monitoring an operating parameter of a refrigeration system that includes a first condensing unit having a first control module and a second condensing unit having a second control module, the first and second condensing units each having at least one compressor. The method also includes controlling, with the first control module, the at least one compressor of the first condensing unit based on the monitoring. The method also includes controlling, with the first control module, the at least one compressor of the second condensing unit based on the monitoring. The first control module controls the at least one compressor of the second condensing unit by communicating with the second control module via a communication link.

1 . A method comprising:
 monitoring an operating parameter of a refrigeration system, said refrigeration system including a first condensing unit having a first control module and a second condensing unit having a second control module, said first and second condensing units each having at least one compressor;   controlling, with said first control module, said at least one compressor of said first condensing unit based on said monitoring;   controlling, with said first control module, said at least one compressor of said second condensing unit based on said monitoring, said first control module controlling said at least one compressor of said second condensing unit by communicating with said second control module via a communication link.   
     
     
         2 . The method of  claim 1 , wherein said controlling said at least one compressor of said second condensing unit includes communicating activation and deactivation requests from said first control module to said second control module via said communication link. 
     
     
         3 . The method of  claim 1 , wherein said at least one compressor of said first condensing unit includes a variable capacity compressor and wherein said controlling said at least one compressor of said first condensing unit with said first control module includes varying a capacity of said variable capacity compressor. 
     
     
         4 . The method of  claim 3 , wherein said at least one compressor of said first condensing unit includes a fixed capacity compressor and wherein said controlling said at least one compressor of said first condensing unit with said first control module includes controlling said variable capacity compressor prior to controlling said fixed capacity compressor. 
     
     
         5 . The method of  claim 4 , wherein said first control module varies said capacity of said variable capacity compressor to a threshold capacity prior to controlling said fixed capacity compressor. 
     
     
         6 . The method of  claim 5 , wherein said first control module varies said capacity of said variable capacity compressor to a maximum capacity prior to activating said fixed capacity compressor. 
     
     
         7 . The method of  claim 1 , wherein said at least one compressor of said second condensing unit includes a variable capacity compressor and wherein said controlling said at least one compressor of said second condensing unit with said first control module includes varying a capacity of said variable capacity compressor. 
     
     
         8 . The method of  claim 7 , wherein said controlling said at least one compressor of said second condensing unit includes communicating activation and deactivation requests from said first control module to said second control module via said communication link. 
     
     
         9 . The method of  claim 7 , wherein said at least one compressor of said second condensing unit includes a fixed capacity compressor and wherein said controlling said at least one compressor of said second condensing unit with said first control module includes controlling said variable capacity compressor prior to controlling said fixed capacity compressor. 
     
     
         10 . The method of  claim 9 , wherein said first control module varies said capacity of said variable capacity compressor to a threshold capacity prior to controlling said fixed capacity compressor. 
     
     
         11 . The method of  claim 10 , wherein said first control module varies said capacity of said variable capacity compressor to a maximum capacity prior to activating said fixed capacity compressor. 
     
     
         12 . The method of  claim 1 , said monitoring said operating parameter of said refrigeration system including monitoring a suction pressure of said refrigeration system, said method further comprising:
 comparing said suction pressure to a set point;   wherein said first control module controls said at least one compressor of said first condensing unit and said at least one compressor of said second condensing unit based on said comparing.   
     
     
         13 . The method of  claim 1 , said monitoring said operating parameter of said refrigeration system including monitoring a compressor operating parameter including at least one of a suction temperature, a discharge temperature, and a discharge pressure of said refrigeration system, said method further comprising:
 comparing said compressor operating parameter to a set point;   wherein said first control module controls said at least one compressor of said first condensing unit and said at least one compressor of said second condensing unit based on said comparing.   
     
     
         14 . A refrigeration system comprising:
 a first condensing unit having a first control module and at least one compressor;   a second condensing unit having a second control module and at least one compressor;   a communication link that enables communication between said first and second control modules;   wherein said first control module controls said at least one compressor of said first condensing unit and controls said at least one compressor of said second condensing unit by communicating with said second control module via said communication link.   
     
     
         15 . The refrigeration system of  claim 14 , wherein said first control module communicates activation and deactivation requests to said second control module via said communication link. 
     
     
         16 . The refrigeration system of  claim 14 , wherein said at least one compressor of said first condensing unit includes a variable capacity compressor and wherein said first control module controls said at least one compressor of said first condensing unit by varying a capacity of said variable capacity compressor. 
     
     
         17 . The refrigeration system of  claim 16 , wherein said at least one compressor of said first condensing unit includes a fixed capacity compressor and wherein said first control module controls said at least one compressor of said first condensing unit by controlling said variable capacity compressor prior to controlling said fixed capacity compressor. 
     
     
         18 . The refrigeration system of  claim 17 , wherein said first control module varies said capacity of said variable capacity compressor to a threshold capacity prior to controlling said fixed capacity compressor. 
     
     
         19 . The refrigeration system of  claim 18 , wherein said first control module varies said capacity of said variable capacity compressor to a maximum capacity prior to activating said fixed capacity compressor. 
     
     
         20 . The refrigeration system of  claim 14 , wherein said at least one compressor of said second condensing unit includes a variable capacity compressor and wherein said first control module controls said at least one compressor of said second condensing unit by varying a capacity of said variable capacity compressor. 
     
     
         21 . The refrigeration system of  claim 20 , wherein said first control module controls said at least one compressor of said second condensing unit by communicating activation and deactivation requests to said second control module via said communication link. 
     
     
         22 . The refrigeration system of  claim 20 , wherein said at least one compressor of said second condensing unit includes a fixed capacity compressor and wherein said first control module controls said at least one compressor of said second condensing unit by controlling said variable capacity compressor prior to controlling said fixed capacity compressor. 
     
     
         23 . The refrigeration system of  claim 22 , wherein said first control module varies said capacity of said variable capacity compressor to a threshold capacity prior to controlling said fixed capacity compressor. 
     
     
         24 . The refrigeration system of  claim 23 , wherein said first control module varies said capacity of said variable capacity compressor to a maximum capacity prior to activating said fixed capacity compressor. 
     
     
         25 . The refrigeration system of  claim 14 , wherein said first control module receives suction pressure data corresponding to a suction pressure of said refrigeration system, compares said suction pressure to a set point, and controls said at least one compressor of said first condensing unit and said at least one compressor of said second condensing unit based on said comparison. 
     
     
         26 . The refrigeration system of  claim 14 , wherein said first control module receives compressor data including at least one of suction temperature data corresponding to a suction temperature of said refrigeration system, discharge pressure data corresponding to a discharge pressure of said refrigeration system, and discharge temperature data corresponding to a discharge temperature of said refrigeration system, compares said compressor data to a set point, and controls said at least one compressor of said first condensing unit and said at least one compressor of said second condensing unit based on said comparison.