Copeland 529-0220-01 Thermistor

The Copeland 529-0220-01 Discharge Line Thermistor is the OEM temperature sensor that reads the temperature of the refrigerant discharge line leaving the compressor. It is a brass-cased thermistor probe on a two-conductor black lead ending in a white two-position plug-in connector, so it connects to the compressor's electronic control module or system controller without splicing. Discharge-line temperature climbs fast when a compressor is in trouble, so this sensor gives the control an early warning of overheating and lets it alert or shut the compressor down before the oil breaks down and valves, scrolls or bearings are damaged. Copeland's CoreSense Diagnostics literature describes discharge line temperature probes plugging into the module's thermistor input to protect against high discharge temperature.

A thermistor is a temperature-sensitive resistor; most discharge-line types are negative temperature coefficient (NTC), meaning resistance drops as the line gets hotter. The control reads that resistance and converts it to a temperature. A failed, open, shorted or poorly mounted sensor shows up as nuisance high-discharge-temperature lockouts, erratic temperature readings, a sensor fault or open-circuit code, or no protection at all. When you install the replacement, mount it on the discharge line close to the compressor outlet just as the original was, with firm contact against clean tubing, and insulate it the way the original was so ambient air does not skew the reading. Match the plug-in connector to your control before ordering.

Key Benefits

• Early Overheat Warning: Reads discharge line temperature continuously so the control can react before compressor damage occurs.
• OEM Copeland Sensor: Specified by Copeland for use with its compressor controls, so the resistance curve matches what the control expects.
• Plug-In Connector: The white two-position connector plugs straight into the control; no splicing or crimping.
• Quick Diagnostic Fix: Eliminates false high-discharge trips and sensor fault codes caused by an aged or damaged probe.

Common Questions

• How do I test the thermistor? Unplug it and measure resistance across the two conductors, then compare that reading at the line temperature to the sensor chart for your control. An open or shorted reading means the sensor needs replacing.
• Where does it mount? On the discharge line near the compressor outlet, in the same position as the original sensor, snug against the tube and insulated.
• How do I confirm it is the right part? Match the number 529-0220-01 and the connector style to your original sensor or your compressor parts list.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.