OEM Carrier 1-Pole Contactor 25A 24V Coil — HN51KB024 for Model PH12NA030000ABAA

This is the genuine OEM Carrier contactor (part# HN51KB024), the factory-specified replacement for the Carrier PH12NA030000ABAA heat pump system. The contactor is a high-voltage relay controlled by the 24V thermostat signal — when the thermostat calls for cooling or heating, the contactor closes to allow line-voltage power to flow to the compressor and/or fan motor. When the contactor fails, the most common symptoms include the outdoor unit not starting at all, a continuous buzzing or chattering sound from the disconnect box, or burned/welded contacts that keep the unit running non-stop even when the thermostat is off.

• Specs: 1-Pole | 24V AC 50/60Hz Coil | 25 FLA (Full Load Amps) | Definite Purpose design | Factory OEM part number HN51KB024
• OEM vs Generic: This is a genuine Carrier OEM contactor with exact-fit terminals and factory-rated contact materials. Aftermarket units often use lower-grade silver alloy contacts that pit and weld faster under repeated switching cycles, shortening overall system life.
• Install difficulty: 2/5 — Always disconnect and lock out all power before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Photograph all wiring before disconnecting terminals. Verify contact pull-in with a 24V test signal after installation.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Direct OEM replacement for Carrier model PH12NA030000ABAA. Verify your unit's data plate lists a 1-pole, 24V coil contactor before ordering. Our fitment team is available to confirm compatibility before you buy — order with confidence and get it shipped today.