OEM Carrier Control Transformer 40VA 120V/24V for Model C48A502764

This is the factory-specified OEM replacement transformer (part number HT01BD702) for the Carrier C48A502764 packaged unit. The transformer steps down line voltage from 120V to 24V to power the entire low-voltage control circuit — including the thermostat, contactor coil, and control board. When this transformer fails, absolutely nothing in the control system responds: the thermostat goes blank, the system won't call for heating or cooling, and you may measure zero volts on the secondary terminals. It's often the first component to check when a unit goes completely unresponsive.

• Specs: 40VA rating | Primary: 120V | Secondary: 24V | OEM part number HT01BD702 | Factory-matched impedance and thermal protection
• OEM vs Generic: OEM transformers are wound to exact VA and voltage tolerances for the C48A502764 control circuit. Undersized or off-tolerance generic units can overheat under peak control load, causing nuisance trips or premature failure that damages downstream components.
• Install difficulty: 2/5 — Disconnect power at the disconnect box before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to verify 24V output after install). Label or photograph all wiring connections before removing the old transformer.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Orders ship same business day from our warehouse stock.

Compatibility: Engineered and factory-matched for the Carrier C48A502764 packaged unit. Always confirm your existing transformer's VA rating and primary/secondary voltages against your unit's data plate before ordering. Need fitment confirmation? Our HVAC parts specialists verify compatibility before you buy — no guesswork required. In stock and ships today.