OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3GNAA24040AA

This is the factory OEM control transformer for the Carrier PY3GNAA24040AA packaged unit, identified by part number HT01BD209. The transformer steps down line voltage (208/240V) to the 24V signal that powers your thermostat, control board, contactor coil, and every other low-voltage component in the system. When it fails, the result is complete loss of control circuit function — a blank thermostat, a system that won't respond to any call for heating or cooling, or a tripped secondary fuse caused by a shorted low-voltage circuit.

• Specs: 40VA | 208/240V primary | 24V secondary | 50/60 Hz | Replaces HT01BD207, HT01CN232 & 9076-00
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances. Undersized or off-tolerance aftermarket units can overheat, blow fuses repeatedly, or damage sensitive control boards over time.
• Install difficulty: 2/5 — De-energize the unit at the disconnect before starting. Tools needed: multimeter (verify 0V at transformer terminals), flathead and Phillips screwdrivers, wire nuts or spade connectors. Always confirm primary and secondary wiring polarity matches the old unit before powering back up.
• Warranty: 1-year OEM factory warranty. Same-business-day shipping from our warehouse stock.

Compatibility: Direct OEM replacement for Carrier PY3GNAA24040AA packaged units. Verify existing transformer VA rating and primary voltage on your unit's data plate before ordering. Cross-references: HT01BD207, HT01CN232, 9076-00. Need help confirming fitment? Our team checks compatibility before you order — ships today.