OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3PNA048090NA

This genuine OEM Carrier control transformer (part #HT01BD209) is the factory-specified replacement for the Carrier PY3PNA048090NA packaged unit. The transformer steps down 208/240V line voltage to the 24V AC signal that powers your thermostat, control board, contactor coil, and all low-voltage safety circuits. When this transformer fails, the entire control circuit goes dark — the thermostat goes blank, the system won't respond to any calls for heating or cooling, and no error codes are displayed because the board itself has no power.

• Specs: 40VA capacity | 208/240V primary input | 24V secondary output | 50/60 Hz rated | OEM part number HT01BD209 | Also cross-references HT01BD207, HT01CN232, and 9076-00
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and voltage tolerances. Generic alternatives are often under-rated for VA capacity, causing premature failure under full control-circuit load — especially in systems with multiple zones or add-on accessories.
• Install difficulty: 2/5 — Shut off all power at the disconnect and breaker before touching any wiring. Tools needed: flathead and Phillips screwdriver, needle-nose pliers, multimeter (to confirm 24V output after install). Always document existing wiring with a photo before disconnecting leads.
• Warranty: 1-year OEM manufacturer warranty. In-stock and ships same business day from our warehouse.

Compatibility: Factory-matched replacement for Carrier model PY3PNA048090NA packaged heating and cooling unit. Verify your unit's data plate shows 208/240V supply voltage before ordering. Not for use on 460V systems — see HT01BD702 for 460V applications. Questions about fitment? Our HVAC parts team confirms compatibility before you order.