Trane P/N CTR03021 – Genuine OEM Definite Purpose Contactor (2-Pole, 24V, 40A)

The Trane CTR03021 is a Genuine Original Equipment Manufacturer (OEM) definite purpose contactor, primarily used in Trane and American Standard air conditioning and heat pump systems. This heavy-duty 2-pole contactor is engineered to manage the high-current electrical loads of compressors and fan motors, ensuring reliable system start-ups and operation. Choosing an authentic Trane replacement ensures the exact electrical ratings and mounting compatibility required by your HVAC unit, preventing premature component failure or safety hazards common with lower-quality generic alternatives. 

Being an authentic OEM component, the CTR03021 features high-grade electrical contacts and a durable housing designed for superior heat resistance and electrical conductivity. This specific model is a standard replacement part, providing a stable 24V control circuit for single-phase equipment. Installing the original factory part maintains the system's UL/CSA certifications and ensures compliance with factory-spec safety protocols.

Key Features and Function:

• Definite Purpose Design: Optimized specifically for HVAC and refrigeration systems with a focus on durability and high cycle life.
• Genuine OEM Reliability: Official Trane replacement built to factory standards for exact fitment and long-term durability.
• Enhanced Contact Life: High-grade contacts resist pitting and welding under heavy electrical loads.
• Standard Mounting: Features a universal foot-mounting base that allows for easy replacement in most 2-pole applications. 

Product Details and Key Specifications:

• Part Number: CTR03021
• Catalog #: N/A (Part number serves as catalog ID)
• Manufacturer: Trane / American Standard
• Part Type: Definite Purpose Contactor
• Poles: 2-Pole
• Coil Voltage: 24 VAC
• Full Load Amps (FLA): 40A
• Resistive Amps (RES): 40A
• Switching Voltage: Up to 600 VAC
• Terminal Connection: Lug or Quick Connect
• Gross Shipping Weight: 0.7 LB 

🛠️ HVAC Depot Pro Tip: The "Pitting and Buzzing" Test

Over time, the high-voltage contacts inside your CTR03021 will begin to "pit" or develop carbon buildup from electrical arcing. If you hear a loud "buzzing" or "chattering" sound when the unit calls for cooling, or if your outdoor fan runs but the compressor won't start, the contactor is likely failing. Even if the coil tests fine with a multimeter, excessive pitting creates high resistance that can overheat and destroy your compressor. Always replace a noisy or burnt contactor immediately to avoid a much more expensive repair. 

Cross-Reference:

The CTR03021 is a direct OEM replacement for the following part numbers:

• OEM & Catalog Numbers: CTR03021, CNT03021, HW20AA107, 3021.
• Brand Specific Replacements: Honeywell DP2030A5002, Supco DP30242, Mars 33234. 

Extensive Model Compatibility List:

Note: Use 'CTRL+F' to search for your specific model:

• Trane/American Standard AC and HP Units (Specific Models):
• 4TTA3030A1000AA, 4TTA3036A1000AA, 4TTA4030A1000AA, 4TTA4036A1000AA
• 2TTA3F36A1000AA, 2TTB3F36A1000AA
• 4TWB3030A1000AA, 4TWB3036A1000AA