OEM Carrier Transformer 120V–24V 40VA for Model YAC1840YAC101K

This OEM replacement transformer (Part # P201-35150) is the factory-specified step-down transformer for the Carrier YAC1840YAC101K packaged unit. Its job is critical but simple: it converts 120V line voltage down to 24V to power the entire low-voltage control circuit — including the thermostat, contactor coil, and control board. When the transformer fails, absolutely nothing in the system responds. You'll see a blank thermostat screen, no cooling calls answered, and often a tripped fuse on the secondary side.

• Specs: Input: 120V AC | Output: 24V AC | VA Rating: 40VA | OEM Part Number: P201-35150 | Factory-matched insulation class and wire gauge
• OEM vs Generic: This is the exact factory-spec OEM transformer. Generic transformers frequently ship with under-rated VA capacity, causing thermal shutdowns under load and repeat fuse failures within months.
• Install Difficulty: 2/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter, wire nuts. Always verify 24V output on the secondary terminals before reassembling the control panel.
• Warranty: 1-year OEM factory warranty. In stock and ships the same business day from our warehouse.

Compatibility: Designed for the Carrier YAC1840YAC101K packaged unit. Verify primary voltage (120V) and VA rating on your unit's data plate before ordering. Not sure if this is your part? Our HVAC fitment team is standing by — order with confidence.