Trane CNT03775 Defrost Control Spdt 10-50F Capillary

Product Description

The TRANE CNT03775 is a defrost control designed for use in heat pump and refrigeration systems where reliable freeze-protection switching is required. This single-pole double-throw (SPDT) control monitors temperature through a capillary sensing element and initiates or terminates defrost cycles based on a setpoint range of 10 to 50 degrees F. The capillary tube lengths of 50 and 52.5 inches allow flexible placement of the sensing element against the outdoor coil. Licensed HVAC technicians install this control as part of routine defrost system maintenance or component-level repair.

The CNT03775 is suited for residential and light commercial heat pump applications where outdoor coil icing must be managed to maintain system efficiency. The SPDT switching configuration allows the control to break one circuit and make another simultaneously, which is the standard logic used in defrost relay and control board interfaces. This part is sourced directly from Trane as an OEM replacement component.

Key Features

• SPDT switching action supports standard defrost control circuit wiring
• Temperature sensing range of 10 to 50 degrees F covers typical outdoor coil defrost thresholds
• Dual capillary tube lengths of 50 and 52.5 inches provide installation flexibility for coil placement
• OEM Trane part for accurate form, fit, and function replacement
• Capillary-based sensing provides direct contact temperature measurement at the coil surface

Compatibility

Designed as an OEM-style replacement defrost control for Trane heat pump systems requiring an SPDT capillary-type defrost thermostat in the 10 to 50 degrees F operating range.

Installation Notes

Installation should be performed by a licensed HVAC technician. Disconnect and lock out all power to the unit before removing or installing the control. Route and secure the capillary tube carefully against the coil surface without kinking, as damage to the capillary will cause incorrect sensing. Follow applicable local codes and manufacturer wiring diagrams when reconnecting the SPDT terminals.

Technical Specifications

• Switching Type: SPDT (Single-Pole Double-Throw)
• Temperature Range: 10 to 50 degrees F
• Capillary Length: 50 and 52.5 inches
• Control Type: Defrost Control

Standard Information

• Brand: TRANE
• Manufacturer Part Number: CNT03775