OEM Carrier 40VA Control Transformer for Model YAC48140YAC303T

This OEM replacement transformer (part number P201-35150) is the factory-specified step-down transformer for the Carrier YAC48140YAC303T packaged unit. It converts 120V (or 208/240V depending on configuration) line voltage to the 24V AC signal that powers your thermostat, control board, contactor coil, and all low-voltage switching logic. When the transformer fails, the entire control circuit goes dark — the thermostat becomes unresponsive, the unit will not start, and no error codes will display because the board itself has lost power.

• Specs: 40VA rating | 24V secondary output | Factory-matched impedance and VA capacity | Direct OEM drop-in replacement for P201-35150
• OEM vs Generic: OEM transformers are wound to exact factory VA ratings and insulation class, ensuring the secondary voltage stays stable under full control-circuit load. Generic units are often underrated, leading to voltage sag that causes erratic contactor chatter and nuisance lockouts.
• Install Difficulty: 2/5 — Shut off all power at the disconnect and breaker before servicing. Tools needed: multimeter, flathead and Phillips screwdrivers, wire stripper, needle-nose pliers. Always verify 0V at primary terminals with a meter before handling. Label all control wiring before disconnecting.
• Warranty: 1-year OEM factory warranty against defects. In stock and ships same business day from our warehouse.

Compatibility: Designed for Carrier model YAC48140YAC303T packaged units. Confirm your existing transformer's VA rating and primary voltage on the unit data plate before ordering. If your secondary output reads below 22V under load, transformer replacement is indicated. Need fitment help? Our HVAC parts specialists confirm compatibility before you buy.