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OEM Carrier 40VA 120V to 24V Control Transformer for C4850C50ZG055900 — Ships Today
Carrier

OEM Carrier 40VA 120V to 24V Control Transformer for C4850C50ZG055900 — Ships Today

SKU: CARRIE-C4850C50ZG055900-TRANSFORMER-HT01BD236 Brand: Carrier
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Texas CMBL #19328542014
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OEM Carrier Transformer 40VA 120V/24V for Model C4850C50ZG055900

This OEM step-down transformer (part number HT01BD236) is the factory-specified replacement for the Carrier C4850C50ZG055900 packaged unit. The transformer converts 120V line voltage to the 24V AC control circuit voltage that powers your thermostat, control board, contactor coil, and all low-voltage safety controls. When the transformer fails, the entire control circuit goes dark — the thermostat loses power, the system won't respond to any call for heating or cooling, and you may measure zero volts at the secondary terminals with line voltage confirmed at the primary.

  • Specs: Input 120V AC | Output 24V AC | 40VA rating | OEM part number HT01BD236 | Factory-matched impedance and VA capacity for the C4850C50ZG055900 control circuit
  • OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerance specifications for this unit. Undersized or off-spec generic transformers can overheat, trip internal breakers repeatedly, or damage downstream control boards — OEM is the only safe choice for packaged commercial equipment.
  • Install difficulty: 2/5 — Shut off all power at the disconnect before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label all low-voltage wiring before disconnecting. Verify 24V output with a multimeter after installation before restoring full system power.
  • Warranty: 1-year OEM factory warranty against defects. In stock and ships same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier C4850C50ZG055900 packaged unit. Always verify your existing transformer's input/output voltage and VA rating on the data plate or unit wiring diagram before ordering. Need fitment confirmation? Our HVAC parts specialists verify compatibility before you buy — contact us anytime.

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 $99
  • 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 C4850C50ZG055900 — Ships Today?
Yes. This is the factory-specified OEM transformer for the Carrier C4850C50ZG055900 — Ships Today. 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 C4850C50ZG055900 — Ships Today?
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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