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OEM Carrier Transformer 40VA 208/240V–24V for SUBCLR50HJ440478
Carrier

OEM Carrier Transformer 40VA 208/240V–24V for SUBCLR50HJ440478

SKU: CARRIE-SUBCLR50HJ440478-TRANSFORMER-HT01BD209 Brand: Carrier

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Texas CMBL #19328542014
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Govt POs Accepted

OEM Carrier 40VA Control Transformer 208/240V to 24V — HT01BD209 for Model SUBCLR50HJ440478

This OEM Carrier control transformer (part number HT01BD209) is the factory-specified replacement for the SUBCLR50HJ440478 unit. The transformer steps down 208/240V line voltage to the 24V signal used by your thermostat, control board, contactor coil, and all low-voltage safety controls. When this component fails, the result is total silence — no thermostat response, no call for heat or cooling, and no system operation of any kind. A failed or shorted transformer is also a common cause of blown 3A control fuses and tripped secondary circuits.

  • Specs: 40VA rated capacity | Primary: 208/240V | Secondary: 24V | 50/60Hz dual frequency | Class 2 control transformer
  • OEM vs Generic: The OEM HT01BD209 is wound and potted to Carrier's exact VA and impedance tolerances. Undersized aftermarket transformers can run hot, trip thermal cutoffs, or fail to sustain voltage under full control-circuit load — leading to nuisance lockouts.
  • Install difficulty: 2/5 — Always disconnect power at the breaker before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter (verify 24V output after install). Label and photograph all low-voltage wiring before disconnecting. Primary wires are typically black (208V tap) and white; secondary outputs are red and common.
  • Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse. Replaces superseded part numbers HT01BD207, HT01CN232, and 9076-00.

Compatibility: Designed for Carrier model SUBCLR50HJ440478. Always verify primary voltage (208V vs 240V) on your unit's data plate to confirm correct tap wiring before installation. Compatible with both 50Hz and 60Hz applications. Questions about fitment? Our HVAC parts team verifies compatibility before you order — order with confidence and get it shipped 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 SUBCLR50HJ440478?
Yes. This is the factory-specified OEM transformer for the Carrier SUBCLR50HJ440478. 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 SUBCLR50HJ440478?
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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Mike Rivera
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