OEM Carrier 40VA Control Transformer HT01BD209 for Model PY3GPAA30040NA

This OEM control transformer is the factory-specified replacement for the Carrier PY3GPAA30040NA packaged unit. The transformer steps down 208/230V line voltage to the 24V signal used by the thermostat, control board, contactor coil, and every other low-voltage component in the system. When it fails, the entire control circuit goes dark — the thermostat goes blank, the unit will not respond to any call for heating or cooling, and in some cases a tripped secondary fuse is the only visible clue. Always check the transformer output with a multimeter before replacing other components, as a failed transformer is one of the most commonly misdiagnosed "board failure" calls in the field.

• Specs: 40VA capacity | 208/230V primary input | 24V secondary output | 50/60 Hz | Class 2 control transformer | Foot-mount bracket included
• OEM vs Generic: This genuine Carrier OEM unit is wound to exact VA and insulation-class specifications. Off-brand transformers rated at 40VA may sag under sustained load, causing intermittent control lockouts and nuisance faults that are difficult to diagnose.
• Install difficulty: 2/5 — Shut off power at the disconnect and breaker before starting. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Note wire colors and terminal labels before disconnecting the old unit. Verify 24V output before buttoning up the panel.
• Warranty & Supersession: 1-year OEM factory warranty. Directly replaces obsolete part numbers HT01BD207, HT01CN232, and 9076-00. Ships same business day from our warehouse.

Compatibility: Engineered for Carrier model PY3GPAA30040NA packaged gas/electric units. Confirm your unit's data plate shows 208/230V single-phase primary voltage before ordering. Our fitment team is available to verify compatibility prior to purchase — no guesswork required.