OEM Carrier Control Transformer 40VA 208/230V — HT01BD209 for Model PY3PPA030040NA

This is the genuine OEM Carrier control transformer (part #HT01BD209) factory-specified for the Carrier PY3PPA030040NA packaged unit. The transformer steps down 208/230V line voltage to 24V to power the entire low-voltage control circuit — including the thermostat, contactor coil, control board, and safety switches. When this transformer fails, the result is a completely unresponsive system: the thermostat goes blank, no contactors pull in, and no call for heating or cooling is answered. It is one of the first components to diagnose when nothing in the system responds.

• Specs: 208/230V Primary | 24V Secondary | 40VA Rating | 50/60 Hz | OEM Part # HT01BD209 | Also cross-references HT01BD207, HT01CN232, 9076-00
• OEM vs Generic: This is a genuine Carrier OEM transformer — factory wound to exact VA and voltage tolerances. Generic transformers can run under-rated VA, causing voltage sag under load and nuisance tripping of downstream boards and relays.
• Install difficulty: 2/5 — Disconnect all power before servicing. Tools needed: multimeter (verify 0V before touching terminals), wire stripper, #2 Phillips screwdriver. Label all 24V secondary wires before removing the old unit. Always verify 24V output with a meter before closing the panel.
• Warranty: 1-year OEM factory warranty. In-stock — ships same business day from our warehouse.

Compatibility: Engineered as the direct factory replacement for Carrier model PY3PPA030040NA. This transformer also cross-references OEM part numbers HT01BD207, HT01CN232, and 9076-00 — verify your existing part number against these before ordering. Questions about fitment? Our HVAC parts specialists confirm compatibility before you buy.