OEM Carrier Transformer 40VA 120V to 24V for Model C50A402761

This is the factory OEM replacement transformer (part number HT01BD236) for the Carrier C50A402761 commercial rooftop unit. The transformer steps down 120V line voltage to the 24V signal used by your thermostat, control board, contactor coils, and all low-voltage safety circuits. When this component fails, the entire control circuit goes dead — the thermostat becomes unresponsive, the system will not start, and no fault codes will display. A failed transformer is often misdiagnosed as a control board failure, making correct part identification critical before replacing more expensive components.

• Specs: 40VA rating | 120V primary / 24V secondary | Class 2 control circuit transformer | OEM part number HT01BD236 | Factory-matched output for Carrier commercial rooftop controls
• OEM vs Generic: This OEM transformer is wound to Carrier's exact VA and voltage tolerance specifications. Generic transformers often run at reduced VA output, causing nuisance tripping of secondary fuses and intermittent low-voltage faults under full control-circuit load.
• Install difficulty: 2/5 — Shut off all power to the unit at the disconnect before proceeding. Tools needed: flathead and Phillips screwdrivers, wire nuts or spade connectors, multimeter. Verify 0V at primary terminals before touching wiring. Photograph all connections before removal.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Ships same business day from our stocked warehouse.

Compatibility: Engineered specifically for the Carrier C50A402761 commercial packaged rooftop unit. Always verify your existing transformer's VA rating and primary/secondary voltages against your unit's wiring diagram before ordering. Need fitment confirmation? Our HVAC parts specialists verify compatibility before you purchase — same-day shipping on all in-stock orders.