OEM Carrier 1-Pole Contactor 30 Amp 24V Coil for Model PH4ZNA042000AA (HN51KC024)

This is the factory-authorized OEM replacement contactor for the Carrier PH4ZNA042000AA heat pump system. The contactor is the high-voltage relay that receives a low-voltage (24V) signal from your thermostat and closes the circuit to power the compressor and/or condenser fan motor. When the contactor fails — due to pitted or burned contacts, a welded-shut plunger, or an open coil — the most common symptoms are an AC or heat pump that won't turn on at all, a unit that runs constantly without shutting off, or a compressor that hums but fails to start. Replacing a failed contactor restores full system operation and protects your compressor from additional damage.

• Specs: 1-Pole | 24 VAC Coil Voltage | 30A Full Load Amps (FLA) | 150A Locked Rotor Amps (LRA) | 50/60 Hz | OEM Part# HN51KC024
• OEM vs Generic: This is a genuine Carrier Factory Authorized Part built to exact factory tolerances. Generic contactors often use lower-grade contact materials that pit and weld faster under compressor load — OEM ensures the correct pull-in voltage, contact gap, and contact silver-alloy rating for long service life.
• Install Difficulty: 2/5 — Shut off power at the disconnect and breaker before opening the unit. Photograph all wiring before disconnecting. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, non-contact voltage tester. Verify 24V coil pull-in after installation with a thermostat call for cooling.
• Warranty & Shipping: Backed by a 1-year OEM factory warranty. In-stock and ships same business day from our warehouse — get your system back up fast.

Compatibility: Engineered for the Carrier PH4ZNA042000AA heat pump. Always confirm the OEM part number on your unit's wiring diagram or data plate matches HN51KC024 before ordering. Our HVAC parts team is available to verify fitment if you have any questions before you buy.