OEM Carrier Transformer 40VA 120V to 24V Control Circuit for Model C48A505051

This OEM replacement transformer (part number HT01BD236) is the factory-specified control circuit transformer for the Carrier C48A505051 packaged unit. The transformer steps down line voltage from 120V to the 24V signal required by the thermostat, control board, contactor coil, and all low-voltage safety circuits. When the transformer fails, the entire control circuit goes dark — your thermostat becomes unresponsive, the system won't call for heating or cooling, and in many cases the unit appears completely dead despite full line voltage being present.

• Specs: 40VA rating | 120V primary / 24V secondary | Class 2 output | Factory-matched to Carrier C48A505051 control board wiring harness
• OEM vs Generic: This is a genuine OEM Carrier transformer built to exact factory VA ratings and insulation class. Generic transformers are frequently undersized and may cause nuisance tripping of the thermal overload, particularly in units with multiple 24V accessories such as humidistats or zone controllers.
• Install difficulty: 2/5 — Always shut off power at the disconnect and breaker before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, and wire nuts. Confirm 24V output at secondary terminals before reassembling the control compartment.
• Warranty: 1-year OEM factory warranty. In-stock units ship same business day from our warehouse.

Compatibility: Designed for the Carrier C48A505051 packaged unit. Verify primary voltage (120V) and VA rating on your unit's data plate before ordering. If you are unsure of fitment, our HVAC parts specialists are available to confirm compatibility before your purchase. Order today and take advantage of same-day shipping on all in-stock OEM Carrier parts.