OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
This OEM replacement transformer (part number HT01BD236) is the factory-specified control circuit transformer for the Carrier C4850C50ZN055200 packaged unit. The transformer steps down 120V line voltage to 24V AC, powering the thermostat, control board, contactor coil, and all low-voltage control circuit components. When this transformer fails, nothing in the control circuit responds — the thermostat goes blank, the system won't call for heating or cooling, and the unit appears completely dead despite having line voltage present. A shorted transformer may also blow the control circuit fuse repeatedly.
Compatibility: Engineered for Carrier model C4850C50ZN055200 packaged units. Verify the transformer's VA rating and primary/secondary voltage on your unit's wiring diagram or data plate before ordering. Our fitment team is available to confirm compatibility before you buy — same-day shipping ensures you're back up and running fast.