OEM Carrier Contactor 24V 2-Pole for Model PY3GNA024040AA (HN51KB024)

This is the factory-specified OEM contactor for the Carrier PY3GNA024040AA split-system air conditioner. The contactor is the high-voltage relay that receives the 24V signal from your thermostat and switches line-voltage power to the compressor and condenser fan motor. When it fails — due to worn contacts, pitting, or a stuck plunger — the system will either refuse to turn on at all, run continuously without cycling off, or produce a loud chattering or buzzing sound at the outdoor unit.

• Specs: OEM Part # HN51KB024 | 2-Pole design | 24V AC coil voltage | Factory-matched contact rating for Carrier PY3GNA024040AA — exact replacement, no modifications required
• OEM vs Generic: This OEM contactor uses factory-spec silver-alloy contacts for maximum conductivity and arc resistance. Generic contactors often use lower-grade contact materials that pit and fail faster, especially under the high inrush current of a compressor start.
• Install Difficulty: 2/5 — Always disconnect power at both the breaker and the unit disconnect before beginning. Tools needed: flathead and Phillips screwdrivers, 1/4" nut driver, needle-nose pliers, multimeter. Photograph all wiring before removing the old contactor — terminal labeling varies.
• Warranty: 1-year OEM factory warranty. In-stock units ship the same business day from our warehouse.

Compatibility: Designed as a direct OEM replacement for Carrier model PY3GNA024040AA. Always confirm your unit's coil voltage and pole configuration on the existing contactor or data plate before ordering. Our parts specialists are available to verify fitment — contact us before you order if you have any questions.