Abstract: A controller for a chiller includes processing electronics configured to detect a plurality of surge events. The processing electronics calculate a point for each detected surge event in at least a three dimensional coordinate system. The three dimensional coordinate system describes at least three conditions of the chiller when the surge event was detected. The processing electronics are configured to calculate a surface map for the at least three dimensional coordinate system using the calculated points. The processing electronics are further configured to control at least one setpoint for the chiller using the calculated surface map.

Abstract: A capacity control algorithm for a multiple compressor liquid chiller system is provided wherein the speed and number of compressors in operation are controlled in order to obtain a leaving liquid temperature setpoint. In response to an increase in the load in the chiller system, the algorithm determines if a compressor should be started and adjusts the operating speed of all operating compressors when an additional compressor is started. In response to a decrease in the load in the chiller system with multiple compressors operating, the algorithm determines if a compressor should be de-energized and adjusts the operating speed of all remaining operating compressors when a compressor is de-energized.

Abstract: This invention increases efficiency of a refrigeration system by maximizing the cooling of the condenser and reducing unnecessary work done by the compressor. In air cooled systems it will also increase the stability of the fans by reducing fan cycling. The fan controller will utilize an algorithm that will consider the following inputs: oil pressure, compressor suction pressure, expansion valve position, compressor loading, last compressor loading change, and current fan stage. The algorithm uses fuzzy logic to characterize the inputs and generates an output that controls the system cooling fans.

Abstract: This invention increases efficiency of a refrigeration system by maximizing the cooling of the condenser and reducing unnecessary work done by the compressor. In air cooled systems it will also increase the stability of the fans by reducing fan cycling. The fan controller will utilize an algorithm that will consider the following inputs: oil pressure, compressor suction pressure, expansion valve position, compressor loading, last compressor loading change, and current fan stage. The algorithm uses fuzzy logic to characterize the inputs and generates an output that controls the system cooling fans.