OEM Carrier 2-Pole Contactor 24V Coil (HN51KB024) for Model PH11JA018000AAAA

This is the factory OEM replacement contactor for the Carrier PH11JA018000AAAA heat pump system. The contactor is the high-voltage switching relay that receives a 24V signal from the thermostat or control board and closes the circuit to energize the compressor and condenser fan motor. When the contactor fails — due to burned contacts, a stuck armature, or a failed coil — the outdoor unit will not start even though the thermostat is calling for cooling or heating. In some cases, a failed contactor can also weld shut, causing the unit to run continuously regardless of thermostat demand.

• Specs: 2-Pole configuration | 24V AC coil voltage | Factory-rated amperage for Carrier PH11JA018000AAAA | OEM part number HN51KB024
• OEM vs Generic: This OEM contactor features factory-spec silver-alloy contact points rated for exact load tolerances of your system. Generic contactors often use lower-grade contacts that arc and pit faster, leading to premature failure and potential compressor damage.
• Install difficulty: 3/5 — Always disconnect power at the breaker and confirm voltage is absent with a multimeter before beginning. Tools needed: flathead and Phillips screwdrivers, 1/4" and 5/16" nut drivers, needle-nose pliers, multimeter. Photograph all wiring connections before removal.
• Warranty: 1-year OEM manufacturer warranty. Orders placed before cutoff ship same business day from our warehouse.

Compatibility: Designed specifically for the Carrier PH11JA018000AAAA heat pump. Always verify coil voltage and pole configuration against your unit's wiring diagram and data plate before ordering. Need fitment confirmation? Our HVAC parts specialists are standing by — we verify compatibility before you buy.