Same-day shipping on orders before 3PM CST · 15,000+ OEM Parts In Stock · Carrier · Bryant · ICP · Heil · Tempstar
Track Order | 1-800-NHP-HVAC | Trade Accounts

Menu

Home Shop All Account Cart
Home / OEM Carrier Contactor HN51KC024 for M...
OEM Carrier Contactor HN51KC024 for Model HA1AJX018000AAAA
Carrier

OEM Carrier Contactor HN51KC024 for Model HA1AJX018000AAAA

SKU: carrier-contactor-ha1ajx018000aaaa Brand: Carrier
$39.95

Order before 3PM CST — ships same day.
Standard delivery 2-5 business days. Express options at checkout.

OEM Guaranteed

Same-Day Ship

30-Day Returns

Secure Checkout

OEM Carrier Contactor HN51KC024 for Model HA1AJX018000AAAA

This OEM Carrier definite purpose contactor (HN51KC024) is the genuine factory replacement for the Carrier HA1AJX018000AAAA 1.5-ton condensing unit. The contactor is the high-voltage relay that delivers power to the compressor and condenser fan motor whenever the thermostat calls for cooling. Burned, pitted, or welded contacts commonly cause a no-start, a persistent hum, or rapid short-cycling that stresses the compressor. This contactor matches Carrier's original 24V coil voltage, pole configuration, and amp rating, so it seats in the existing bracket and reconnects to the same line, load, and coil terminals without adapters. Installation is a moderate job for a trained technician: shut off power at the disconnect, photograph the wiring, transfer leads one at a time, and verify the contacts pull in cleanly. Genuine OEM ampacity ensures dependable switching and protects the compressor from chatter damage. In stock and ready to ship. Orders placed before 3PM CST ship the same business day to minimize downtime. Fitment guaranteed for the HA1AJX018 series condensing unit.

Compatibility

This part is compatible with Carrier model HA1AJX018000AAAA.

Shipping

Same-day shipping before 3 PM CST. 30-day returns on uninstalled parts.

Shipping Information

  • Orders placed before 3PM CST ship same business day
  • Standard delivery: 2-5 business days
  • Express shipping available at checkout
  • Free shipping on orders over $75
  • Tracking number emailed upon shipment

Return Policy

  • 30-day returns on unused parts in original packaging
  • Electrical parts (capacitors, contactors, control boards) are final sale once installed
  • Email support@nationalhvacparts.com to initiate a return
  • Refunds processed within 5-7 business days

Frequently Asked Questions

Does this Contactor fit my Carrier Model HA1AJX018000AAAA?
Yes. This is the factory-specified OEM contactor for the Carrier Model HA1AJX018000AAAA. It is a direct drop-in replacement that fits without modification. Always verify the model number on your equipment nameplate before ordering.
How do I replace the contactor on my Carrier Model HA1AJX018000AAAA?
Difficulty: Medium (30–45 min)
Step 1: Turn off breaker. Step 2: Open condensing unit panel. Step 3: Photograph ALL wiring on the contactor. Step 4: Label each wire with tape. Step 5: Disconnect wires and remove old contactor. Step 6: Mount new contactor, reconnect wires matching your photo. Step 7: Restore power and test.
My AC clicks but the compressor won’t turn on. What’s wrong?
Clicking from the outdoor unit without the compressor starting = worn contactor. The contactor sends power to the compressor. When its contacts are pitted, it clicks but can’t make solid contact. Look for: visible pitting/burn marks on the contactor face, intermittent operation, or buzzing.
Is this contactor compatible with Bryant or Payne too?
Many Carrier parts are cross-compatible with Bryant and Payne since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across brand labels with different model numbers. To verify: check your Bryant or Payne equipment service manual for cross-compatible part numbers, or email info@nationalhvacparts.com with your model number.
Should I use OEM or aftermarket for my Carrier contactor?
OEM recommended for reliability and warranty compatibility. OEM parts match exact factory specifications for proper fit, performance, and safety. While aftermarket alternatives cost less upfront, the risk of improper fit and reduced lifespan usually makes OEM the better value long-term.
How fast does National HVAC Parts ship?
Orders placed before 3:00 PM CST ship the same business day. Standard delivery is 2–5 business days anywhere in the continental United States. Express shipping available at checkout. We ship from Houston, TX to all 50 states. 30-day return policy on all parts.
Home Shop Search Account Cart