OEM Carrier Single-Pole Contactor 25A 24V Coil — HN51KB024 for Model PH2PNB030000AA

This OEM Carrier contactor (part# HN51KB024) is the factory-specified replacement for the Carrier PH2PNB030000AA heat pump system. The contactor is a high-current relay controlled by the 24V thermostat circuit — when the thermostat calls for cooling or heating, the contactor closes and sends line voltage to the compressor and/or condenser fan motor. When it fails, the most common symptoms are the outdoor unit failing to energize at all, audible chattering or buzzing at the contactor, or burnt/pitted contact points visible on inspection.

• Specs: 1-Pole (single pole) | 25A Full Load Amps (FLA) | 24V AC 50/60Hz Coil | Definite Purpose Contactor | Factory OEM part number HN51KB024
• OEM vs Generic: OEM contactors feature factory-matched contact ratings and coil impedance, ensuring proper pull-in voltage and long contact life. Generic aftermarket contactors may use lower-grade contact materials that pit and weld faster under load, leading to premature failure.
• Install difficulty: 2/5 — Always shut off power at the disconnect and breaker before starting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Photograph all wiring connections before removing the old contactor. Swap wires one at a time to avoid miswiring.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse when ordered before cutoff.

Compatibility: Engineered as the OEM replacement for Carrier model PH2PNB030000AA. Always verify your unit's data plate and existing contactor specs (poles, amperage, coil voltage) before ordering. Not sure if this is the right part? Our HVAC parts specialists verify fitment before you buy — contact us today and get back up and running fast.