OEM Carrier Control Transformer 40VA for Model C48A302752

This OEM replacement transformer (part number HT01BD236) is the factory-specified step-down transformer for the Carrier C48A302752 packaged unit. The transformer converts 120V line voltage down to the 24V signal required by the control board, thermostat, contactor coil, and all low-voltage safety circuits. When this transformer fails, the entire control circuit goes dead — the thermostat loses communication, the unit won't respond to any call for heating or cooling, and you may measure 0V across the secondary terminals with power confirmed at the primary.

• Specs: 40VA rated | 120V primary / 24V secondary | Class 2 control circuit transformer | OEM part number HT01BD236 | Factory-matched impedance and thermal protection
• OEM vs Generic: The OEM HT01BD236 transformer is wound to Carrier's exact VA and impedance specifications. Undersized or off-tolerance generic transformers frequently overheat and trip their internal thermal fuse under normal HVAC control loads, leading to repeat failures and nuisance callbacks.
• Install difficulty: 2/5 — Shut off all power to the unit before beginning. Tools needed: flathead and Phillips screwdriver, multimeter, wire nuts or spade terminals. Photograph all wiring connections before disconnecting. Confirm 24V output at secondary terminals after installation before closing the cabinet.
• Warranty: 1-year OEM factory warranty. In-stock units ship same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Designed for the Carrier C48A302752 packaged unit. Verify your existing transformer's VA rating and primary/secondary voltage on the unit data plate or transformer label before ordering. If your control circuit is blowing fuses repeatedly, inspect for shorted low-voltage wiring before replacing the transformer. Have questions about fitment? Our HVAC parts specialists confirm compatibility before your order ships.