OEM Carrier Transformer 40VA 120V to 24V for Model C50A505061

This OEM Carrier transformer (part number HT01BD236) is the factory-specified replacement for the C50A505061 commercial rooftop unit. The transformer steps down 120V line voltage to the 24V AC signal that powers your entire control circuit — including the thermostat, contactor coils, control board, and safety switches. When this part fails, absolutely nothing responds: the thermostat goes dark, the system won't energize, and no error codes will appear because the control circuit itself has lost power. A blown fuse or failed transformer are the first things to check in a fully non-responsive HVAC system.

• Specs: 40VA rating | 120V primary / 24V secondary | Class 2 output | Factory-matched impedance for stable low-voltage control signal
• OEM vs Generic: This OEM unit (HT01BD236) is built to Carrier's exact VA rating and thermal protection specs. Generic transformers often run underrated VA, causing nuisance trips and premature failure — especially under high-demand multi-zone control wiring loads common in commercial rooftop applications.
• Install difficulty: 2/5 — Shut off all power at the disconnect before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade terminals. Always verify 24V output with a multimeter before reconnecting the control harness. Photograph all wiring connections prior to removal.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier C50A505061 commercial packaged rooftop unit. Always verify your existing transformer's VA rating, primary voltage, and secondary voltage on the unit's data plate or wiring diagram before ordering. Our fitment team is available to confirm compatibility before you purchase — don't guess on a commercial job.