Microprocessor-based controller

摘要

A controller for a gas heat pump system wherein the controller has a variable capacity control capability that responds to thermostat output signals. The variable capacity controller computes real-time performance parameters at variable capacity heating/cooling load conditions of the gas heat pump system. A defrost controller calculates a maximum heat pump operating time period between successive defrost cycles and a minimum heat pump operating time period of each defrost cycle, during a heating mode of the gas heat pump. Such values are calculated as a function of sensed time, temperature and variable capacity operating conditions which are calculated by the variable capacity controller. The controller preferably has a manual mode for verifying correct operation of each actuator of the gas heat pump system, as a function of a sequenced input signal, while the gas heat pump system is in a shutdown mode. The manual mode control also computes and generates an output signal for controlling each actuator to achieve efficient operation control of the gas heat pump system in various operational states, based upon predetermined operating parameters.