OEM Carrier Control Transformer 40VA 120V–24V for Model C50A403061

This OEM Carrier transformer (part number HT01BD236) is the factory-specified replacement for the C50A403061 commercial packaged unit. The transformer steps down 120V line voltage to the 24V AC signal that powers your thermostat, control board, contactors, and every other low-voltage component in the system. When the transformer fails — often from a short in the control circuit or simple age — absolutely nothing responds: the thermostat goes blank, the system won't call for heating or cooling, and no safety controls can operate.

• Specs: 40VA capacity | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01BD236 | Factory-matched for Carrier C50A403061 packaged units
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances required by the control board. Undersized or off-tolerance generic units can overload immediately if a wiring fault exists, and they may not provide stable 24V under full control-circuit load — shortening board life.
• Install difficulty: 2/5 — Always shut off power at the disconnect before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Verify incoming 120V and outgoing 24V with a meter after installation before restoring full power. Photograph all wire connections before disconnecting.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier C50A403061 commercial rooftop/packaged unit. Confirm your existing transformer's primary and secondary voltage ratings and VA capacity on the unit's data plate or wiring diagram before ordering. If your control fuse blows repeatedly, diagnose and repair the downstream short before installing a new transformer — or the replacement will fail as well. Our HVAC parts team is available to verify fitment before you order. In stock — order now and ship today.