Same-day shipping before 3PM CST · 35,000+ OEM Parts · Texas CMBL & SAM.gov Registered · Government POs Accepted

Menu

Home Shop All Account Cart
OEM Carrier Transformer 40VA 120V/24V for C50A905064
Carrier

OEM Carrier Transformer 40VA 120V/24V for C50A905064

SKU: CARRIE-C50A905064-TRANSFORMER-HT01BD702 Brand: Carrier

OEM Guaranteed

Same-Day Ship

30-Day Returns

Secure Checkout

Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

OEM Carrier 40VA Control Transformer HT01BD702 for Model C50A905064

This is the OEM factory-replacement control transformer (part number HT01BD702) for the Carrier C50A905064 commercial rooftop unit. The transformer steps down 120V line voltage to the 24V signal voltage that powers your thermostat, control board, contactor coils, and every other low-voltage control in the system. When this component fails, the entire control circuit goes dark — the thermostat loses power, the unit won't respond to any call for heating or cooling, and nothing works. A failed transformer is one of the most common causes of a completely unresponsive HVAC system.

  • Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01BD702 | Factory-matched impedance and thermal protection
  • OEM vs Generic: This OEM transformer is wound and rated to Carrier's exact factory specifications. Generic units often use undersized copper windings that run hot under full VA load, leading to premature burnout — especially in commercial rooftop applications with multiple control loads.
  • Install difficulty: 2/5 — Disconnect all power before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Note wire colors and terminal positions before removing the old unit. Verify 24V output with a multimeter after installation before closing the cabinet.
  • Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed and factory-specified for the Carrier C50A905064 commercial packaged rooftop unit. Always confirm your unit's control voltage and VA requirements on the data plate before ordering. Our parts specialists are available to verify fitment — order with confidence today.

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 C50A905064?
Yes. This is the factory-specified OEM transformer for the Carrier C50A905064. 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 C50A905064?
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.
Home Shop Search Account Cart
Fitment Guaranteed
MR
Mike Rivera
HVAC Parts Specialist — Online