OEM Carrier Control Transformer 40VA 208/240V to 24V for Model PY3PNA036090AA

This OEM Carrier control transformer (part# HT01BD209) is the factory-specified replacement for the Carrier PY3PNA036090AA system. 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 control circuit components. When it fails, the entire control circuit goes dark — the thermostat becomes unresponsive, the system will not call for heat or cooling, and in some cases a blown internal fuse will be the only visible sign of failure.

• Specs: 40VA rating | 208/240V primary input | 24V secondary output | 50/60Hz | Direct OEM replacement for part numbers HT01BD207, HT01CN232, and 9076-00
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and voltage tolerances. Generic transformers may run undervoltage under load, causing nuisance lockouts and premature contactor coil failure.
• Install difficulty: 2/5 — Shut off power at the disconnect and breaker before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter (verify 24V output after install). Label or photograph all wiring before disconnecting. Fuse the secondary circuit at 3A if not already protected.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse.

Compatibility: Engineered to fit the Carrier PY3PNA036090AA packaged system. Verify your existing transformer's VA rating and primary voltage on the unit's data plate or wiring diagram before ordering. Cross-references: HT01BD207, HT01CN232, 4000A46E07AE28, 9076-00. Questions about fitment? Our HVAC parts specialists verify compatibility before you order — call or chat today.