Method and control system for verifying sensor operation in a refrigeration system

A safety control system for sensors in a refrigeration system including a compressor, a condenser, and an evaporator, comprising:

• a sensor means for sensing an operating condition and for generating a signal in response to the operating condition, said sensor means having a first prescribed operating range prior to startup wherein any signal generated outside said first prescribed range indicates a malfunction of said sensor means and a second prescribed operating range during system operation wherein any preselected number of consecutive signals generated outside said second prescribed range indicates a malfunction of said sensor means,
• processor means connected to said sensor means for monitoring generated signals from said sensor means and for determining whether the signals are within respective said first and said second prescribed operating ranges,
• said processor means further generating a first alarm signal when a monitored signal falls outside said first prescribed operating range prior to startup, and generating a second alarm signal when any monitored preselected number of consecutive signals falls outside said second prescribed operating range during system operation, and
• safety means connected to said processor means for receiving said first and said second alarm signals, for aborting startup upon receiving said first alarm signal, and for shutting down said system upon receiving said second alarm signal, whereby shutdowns of said refrigeration system due to malfunctioning sensors is eliminated.