OEM Carrier 40VA Control Transformer HT01BD702 for Model C50A303564

This OEM Carrier transformer (part number HT01BD702) is the factory-specified step-down transformer for the Carrier C50A303564 commercial packaged unit. The transformer converts 120V line voltage to 24V AC to power the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When this transformer fails, the entire control system goes dead: the thermostat shows no power, nothing responds, and the system will not heat or cool.

• Specs: 40VA rating | 120V primary input | 24V secondary output | Single-phase | Designed to OEM factory tolerances for the C50A303564 control circuit
• OEM vs Generic: This is a genuine OEM Carrier part. Generic transformers may carry incorrect VA ratings or use lower-grade windings, which can cause nuisance tripping, overheating, or premature failure — especially under full control circuit load in a packaged commercial unit.
• Install difficulty: 2/5 — Disconnect power at the breaker and verify zero voltage with a multimeter before touching any terminals. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Always photograph existing wiring before disconnecting the primary and secondary leads.
• Warranty: 1-year OEM factory warranty. Orders placed by 3PM ship same business day from our warehouse.

Compatibility: Engineered for the Carrier C50A303564 commercial rooftop/packaged unit. Verify existing transformer VA rating and primary/secondary voltages on the unit's data plate before ordering. If your low-voltage fuse is also blown, inspect for any short in the 24V circuit before installing the new transformer. Questions about fitment? Our HVAC parts specialists confirm compatibility before you order — no guesswork.