Expansion valve performance monitoring in refrigeration system

A refrigeration system comprising:

• a housing defining a temperature controlled space;
• a thermal exchange system, coupled to the housing, configured to selectively control a temperature of the temperature controlled space, and comprising:
• an actuator coupled to an expansion valve assembly;
• a fan configured to transfer a thermal energy of a refrigerant;
• and
• a controller configured to perform operations comprising:
• controlling the actuator coupled to the expansion valve assembly of the thermal exchange system to drive a superheat of the thermal exchange system to a setpoint that is within a normal operating range of the thermal exchange system, the normal operating range between a maximum superheat and a minimum superheat;
• subsequent to controlling the expansion valve assembly to drive the superheat of the thermal exchange system to the setpoint, determining a present superheat of the thermal exchange system;
• in response to the present superheat of the thermal exchange system being outside of the normal operating range, detecting an electrical property of the expansion valve assembly of the refrigeration system;
• determining that the expansion valve assembly has experienced an electrical failure based on at least the electrical property of the expansion valve assembly;
• in response to the determination that the expansion valve assembly has experienced the electrical failure, generating a first signal indicating that the expansion valve assembly has experienced the electrical failure;
• and
• generating a second signal causing shut down of the fan, based on the superheat of the refrigeration system being outside of the normal operating range.

A controller for diagnosing a refrigeration system, the controller configured to perform operations comprising:

• controlling an expansion valve assembly of the refrigeration system to drive a superheat of the refrigeration system to a setpoint that is within a normal operating range of the refrigeration system that is between a maximum superheat and a minimum superheat for the refrigeration system;
• subsequent to controlling of the expansion valve assembly, determining a present superheat of the refrigeration system;
• detecting, responsive to the present superheat of the refrigeration system being outside of the normal operating range, an electrical property of the expansion valve assembly;
• determining that the expansion valve assembly has experienced an electrical failure based on at least the electrical property of the expansion valve assembly;
• generating, responsive to a determination that the expansion valve assembly has experienced the electrical failure, a first signal indicating that the expansion valve assembly has experienced the electrical failure;
• and
• generating, responsive to the determination that the expansion valve assembly has experienced the electrical failure and responsive to the determined present superheat outside of the normal operating range, a second signal to a compressor of the refrigeration system, the second signal configured to cause a modification in an operation of a fan, the modification in the operation of the fan comprising causing a shut down of the fan.