OEM Carrier 40VA Control Transformer for Model C4850C50Z3030500

This is the factory OEM replacement control transformer (part# HT01BD236) for the Carrier C4850C50Z3030500 packaged unit. The transformer steps down 120V line voltage to the 24V signal used by your thermostat, control board, contactor coil, and all low-voltage safety circuits. When this component fails, the entire control circuit goes dark — the thermostat loses power, the system stops responding to calls for heating or cooling, and no safety lockouts or diagnostics can function.

• Specs: 40VA rated | Primary: 120V | Secondary: 24V | Class 2 control circuit transformer | OEM part number HT01BD236 | Factory-matched for Carrier C4850C50Z3030500
• OEM vs Generic: This OEM transformer is wound to exact VA and voltage tolerances specified by Carrier engineering. Generic transformers frequently underperform on VA capacity, causing nuisance tripping of the internal fuse and premature control board damage under normal load.
• Install difficulty: 2/5 — Shut off all power to the unit at the disconnect before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, wire nuts or spade connectors. Always verify 0V at primary terminals with a multimeter before touching wiring. Photograph all existing wiring connections prior to removal.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. Orders placed before 3PM ship same business day from our climate-controlled warehouse.

Compatibility: Designed as a direct OEM replacement for Carrier model C4850C50Z3030500 packaged units. Verify your existing transformer's VA rating and primary/secondary voltages on the data plate before ordering. If you're unsure of fitment, our HVAC parts specialists confirm compatibility before purchase — no guesswork required.