OEM Carrier 2-Pole Contactor 24V Coil HN51KC024 for Model PH4RNG018000BAAA

This OEM contactor is the factory-specified replacement part for the Carrier PH4RNG018000BAAA heat pump system. The contactor is a high-voltage relay controlled by the 24V signal from your thermostat. When the thermostat calls for cooling or heating, the 24V coil energizes, closing the contactor's poles and sending line voltage to the compressor and condenser fan motor. A failed contactor is one of the most common causes of an outdoor unit that simply won't turn on — even when the indoor air handler is running normally. Symptoms include a buzzing or chattering sound from the disconnect box, a unit that runs continuously without shutting off (welded contacts), or a system that is completely unresponsive to thermostat commands.

• Specs: 2-Pole configuration | 24V coil voltage | Factory OEM part number HN51KC024 | Direct drop-in replacement for Carrier PH4RNG018000BAAA
• OEM vs Generic: This OEM contactor is manufactured to Carrier's exact coil pull-in voltage and contact amp ratings. Generic contactors can have looser tolerances on coil sensitivity and contact material quality, which can lead to premature pitting, welding, and nuisance trips — especially in high-cycle climates.
• Install difficulty: 2/5 — Always disconnect power at both the indoor air handler and the outdoor disconnect before beginning. Tools needed: flathead and Phillips screwdrivers, 1/4" nut driver, needle-nose pliers, and a multimeter for verification. Photograph all wire connections before removing the old contactor.
• Warranty: 1-year OEM factory warranty coverage. In-stock and ships same business day from our warehouse.

Compatibility: Designed as a direct OEM replacement for the Carrier PH4RNG018000BAAA heat pump. Always verify your unit's data plate and existing contactor specs (poles, coil voltage, amperage rating) prior to ordering. Our HVAC parts specialists are available to confirm fitment — contact us before you order if you have any questions.