OEM Carrier Control Transformer 40VA 208/240V to 24V — Model PY3GPAA42060AA (HT01BD209)

This genuine OEM control transformer is the factory-specified replacement for the Carrier PY3GPAA42060AA packaged unit. The transformer steps down 208/240V line voltage to the 24V signal that powers your thermostat, contactor coil, control board, and every low-voltage safety circuit in the system. When it fails, the result is total control loss — the thermostat goes dark, the system won't respond to any call for heating or cooling, and no safety or diagnostic circuits can operate.

• Specs: 40VA capacity | Primary: 208/240V | Secondary: 24V | 50/60Hz rated | OEM Part # HT01BD209 | Replaces HT01BD207, HT01CN232, 9076-00
• OEM vs Generic: The OEM transformer is wound and rated to exact Carrier factory specifications. Generic alternatives may run outside tolerance, causing nuisance tripping of the 3A control fuse or premature failure under high-demand multi-stage systems.
• Install difficulty: 2/5 — Disconnect all power before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Label all low-voltage wires before removal and verify 24V output with a multimeter before closing the unit up.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse.

Compatibility: Designed as the direct OEM replacement for the Carrier PY3GPAA42060AA packaged unit. Verify primary voltage on your unit's data plate (208V or 240V) before ordering — this transformer supports both. Cross-references: HT01BD207, HT01CN232, 4000A46E07AE28, 9076-00. Questions about fitment? Our HVAC parts specialists verify compatibility before you order — same-day shipping on all in-stock parts.