OEM Carrier Control Transformer 40VA 120V/24V for Model C4850C48ZG050500

This OEM replacement control transformer (part# HT01BD236) is the factory-specified unit for the Carrier C4850C48ZG050500 packaged system. The transformer steps down 120V line voltage to the 24V signal required by your thermostat, control board, contactor coil, and all low-voltage safety circuits. When the transformer fails — due to a shorted control wire, overloaded secondary, or age — absolutely nothing in the system responds: the thermostat goes dark, the contactor won't pull in, and no heating or cooling call is processed. It is one of the first components to check when a system is completely unresponsive.

• Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | Foot-mount or chassis-mount bracket | Factory-matched impedance and thermal protection for Carrier C4850C48ZG050500
• OEM vs Generic: The OEM HT01BD236 transformer includes factory-calibrated thermal overload protection that trips and resets automatically on brief overloads. Many generic units use lower-grade cores with ±15% voltage variance, which can damage downstream control boards and thermostats over time.
• Install difficulty: 2/5 — Shut off power at the disconnect and breaker before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire stripper. Confirm 24V output after install before restoring full system power. Label all wires before removing the old unit.
• Warranty: 1-year OEM factory warranty against defects. Orders placed before 3 PM ship same business day from our climate-controlled parts warehouse.

Compatibility: Engineered and tested for Carrier model C4850C48ZG050500 packaged units. Cross-reference OEM part number HT01BD236 against your unit's wiring diagram or data plate to confirm 40VA 120/24V specification before ordering. Our parts specialists are available to verify fitment — contact us before you buy if you have any questions. In stock and ships today.