2-Pole Contactor (40 Amp, 24VAC Coil)

Key Features

• Heavy-Duty 40A Rating: Designed to handle the high inductive loads of large A/C compressors and heat pump motors, providing a significantly longer service life than standard 30A units.
• 2-Pole Configuration: Breaks both legs of a 240V circuit simultaneously, ensuring total power isolation to the equipment when the thermostat is not calling for cooling.
• 24V Low-Voltage Coil: Engineered for an "Exact Fit" with standard residential HVAC control systems, allowing the thermostat to trigger the high-voltage circuit safely.
• Silver Alloy Contacts: Features premium oxide-resistant contact points to prevent welding and pitting, maintaining high conductivity through thousands of cycles.
• Dust-Shielded Design: Built with a protective housing to prevent insects and debris from interfering with the mechanical plunger or the electrical contacts.

Replaces / Cross-Reference Part Numbers

• C240A
• DP40242
• CTR02574
• CONT2P040024V
• HCCY2XU04AA303
• Mars 17421

Compatibility & Fitment

This contactor is a universal replacement for most residential and light commercial HVAC units. Key compatible brands include:

• Air Conditioners & Heat Pumps: Fits units from Carrier, Bryant, Payne, Rheem, Ruud, Goodman, Amana, Lennox, Trane, and American Standard.
• Refrigeration Systems: Compatible with walk-in coolers and commercial refrigeration compressors requiring a 24V control signal.
• Voltage Compatibility: The coil requires 24VAC; the load terminals are rated for use with 120V, 208V, or 240V AC power.

When to Replace

• Humming or Chattering: A loud buzzing noise often indicates that the 24V coil is weak or that the contacts are dirty and unable to pull in fully.
• Condenser Won't Start: The indoor fan is running and the thermostat is set to "Cool," but the outdoor unit is silent, suggesting a failed contactor coil.
• Burned or Pitted Contacts: Visible blackening or "soot" around the metal contact points, which can cause the compressor to overheat or fail to start.
• Welded Contacts: The outdoor fan and compressor continue to run even when the thermostat is turned off, indicating the contacts have melted together.
• Ant/Insect Infestation: Small insects (like "crazy ants") are attracted to the electrical field and can get crushed between the contacts, preventing a solid connection.

Installation Tips

• Safety First: Turn off the power at both the outdoor disconnect box and the main indoor breaker panel. Verify with a multimeter that no voltage is present before touching the wires.
• Label Your Wires: Take a photo of the old contactor before disconnecting. Mark the "Line" (power in), "Load" (to compressor), and "Control" (24V wires from the thermostat) clearly.
• Secure Terminals: Ensure all lug screws are tightened firmly. A loose connection on a 40A circuit will generate extreme heat and can melt the wiring.
• Orientation: While contactors can often be mounted in various positions, mounting it vertically (as originally designed) helps prevent dust and moisture from settling on the moving plunger.
• Verify the Coil: Ensure your system is 24V. If you install a 24V contactor into a system that uses a 120V or 240V control circuit, the coil will burn out instantly.