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This OEM control transformer (part# HT01BD236) is the factory-specified replacement for the Carrier C4850C50Z3055600 packaged unit. The transformer steps down 120V line voltage to the 24V signal used by your thermostat, contactor coil, and control board. When it fails, the entire low-voltage control circuit goes dead — the thermostat goes blank, the system won't respond to any call for heating or cooling, and no components stage on. It is often the first part to check when a system appears completely unresponsive despite confirmed line voltage at the unit.
Compatibility: Designed for the Carrier C4850C50Z3055600 packaged unit. Confirm primary voltage and VA rating on your unit's data plate before ordering. If your system has multiple 24V accessories such as zone boards or humidifiers, verify total VA load does not exceed 40VA. Need help confirming fitment? Our HVAC parts team is standing by — order with confidence and get your system back online today.