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This OEM replacement transformer (part number HT01BD236) is the factory-specified control circuit transformer for the Carrier C50A403552 commercial packaged unit. The transformer steps down line voltage from 120V to 24V AC to power the control board, thermostat, and all low-voltage components throughout the system. When it fails, nothing in the control circuit responds — the thermostat goes blank, the system refuses to start, and the unit appears completely dead despite line power being present. A failed transformer is often confirmed by measuring 0V on the secondary terminals with a multimeter.
Compatibility: Designed specifically for the Carrier C50A403552 commercial rooftop/packaged unit. Verify primary voltage (120V) and VA rating on your unit's wiring diagram or data plate before ordering. Our parts specialists are available to confirm fitment — reach out before you order if you have any questions. In stock and ships today.