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OEM Carrier Transformer 40VA 120V/24V for C50A502551
Carrier

OEM Carrier Transformer 40VA 120V/24V for C50A502551

SKU: CARRIE-C50A502551-TRANSFORMER-HT01BD236 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier 40VA Control Transformer for Model C50A502551

This OEM replacement transformer (part number HT01BD236) is the factory-specified control circuit transformer for the Carrier C50A502551 packaged unit. The transformer steps down line voltage from 120V to 24V to power the control board, thermostat, contactor coil, and all low-voltage safety circuits. When it fails, absolutely nothing in the control system responds — the thermostat goes dark, the unit won't call for heating or cooling, and you may find a blown fuse or tripped breaker on the secondary side.

  • Specs: 40VA rating | 120V primary / 24V secondary | OEM part number HT01BD236 | Factory-matched impedance and thermal protection for reliable low-voltage output
  • OEM vs Generic: This is the genuine Carrier OEM transformer built to exact factory tolerances. Generic transformers frequently underperform on VA capacity, causing control board brownouts, nuisance lockouts, and premature contactor coil failure under full load.
  • Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Verify 24V output after installation before restoring full power. Photograph all wiring connections before disconnecting.
  • Warranty: 1-year OEM factory warranty against defects. In-stock units ship same business day from our warehouse.

Compatibility: Designed specifically for the Carrier C50A502551 commercial rooftop/packaged unit. Always verify transformer VA rating and primary/secondary voltages against your unit's wiring diagram and data plate before ordering. Our fitment team is available to confirm compatibility before you buy — same-day shipping on all in-stock orders.

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 info@nationalhvacparts.com to initiate a return
  • Refunds processed within 5-7 business days

Frequently Asked Questions

Does this Transformer fit my Carrier C50A502551?
Yes. This is the factory-specified OEM transformer for the Carrier C50A502551. 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 transformer on my Carrier C50A502551?
Difficulty: Medium (30–45 min)
Step 1: Turn off breaker. Step 2: Photo wiring connections. Step 3: Disconnect wires from old transformer. Step 4: Remove mounting hardware. Step 5: Install new transformer, reconnect wires matching voltage ratings. Step 6: Verify 24V output with multimeter.
My thermostat has no power. What failed?
Thermostat with no display = failed 24V transformer (or blown control board fuse). Check the 3A/5A fuse on the control board first ($1–$5 fix). If fuse is good but no 24V output from transformer, replace transformer.
Is this transformer 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 transformer?
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.
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