624740R Nordyne DEFROST SENSOR

Description

The 624740R is an OEM coil temperature defrost sensor that accurately detects frost formation on outdoor coils and initiates defrost cycles in Nordyne refrigeration and heat pump systems. It helps maintain optimal temperature levels, prevents ice build-up on the evaporator coil, and ensures efficient heat transfer and system performance. 

Key Features

• Official Nordyne part number 624740R

• Coil temperature sensing element for defrost control

• Durable construction rated for outdoor coil environments

• Two-wire pigtail for straightforward installation

Compatibility

• Refrigeration and heat pump systems requiring defrost management; coil temperature sensor for defrost control.

• Nordyne DD and Q5RE model designations for defrost cycle regulation.

Installation Tips

• Mount the sensor bulb in firm contact with the coil tubing; use the OEM clip or a corrosion-resistant metal clamp to secure it.

• Route and protect the pigtail away from sharp edges, moving parts, and high-heat components; use split-loom tubing if needed.

• Before commissioning, measure the sensor’s resistance at ambient temperature to confirm NTC behavior (for example, ~10 kΩ at 25 °C).

• Inspect wiring connections and defrost control board terminals for corrosion; clean contacts to maintain accuracy and reliability.

Cross-Reference & Resources

• OEM Nordyne 624740 (original version) → 624740R (revised)

• Defrost control board wiring diagrams for DD and Q5RE systems

• PTAC‐style service manual excerpts covering defrost sensor circuits