OEM Carrier 75VA Control Transformer HT01BD242 for Model PH1PNB036000AAAA

This OEM Carrier transformer (part #HT01BD242) is the factory-specified replacement for the Carrier PH1PNB036000AAAA heat pump package unit. The transformer steps down high-voltage line power (208/240/480V) to the 24VAC signal voltage that powers your thermostat, contactor coil, control board, and every other low-voltage component in the system. When it fails, nothing works — the thermostat goes blank, the system won't respond to any call for heating or cooling, and you may blow a 3A control fuse repeatedly. A failed transformer is often misdiagnosed as a control board or thermostat problem, so always confirm 24VAC output at the secondary terminals before replacing other components.

• Specs: 75VA power rating | Primary input: 208/240/480VAC, 50/60Hz | Secondary output: 24VAC | Foot-mount configuration | OEM part #HT01BD242
• OEM vs Generic: This is the genuine Carrier OEM unit, engineered to exact 75VA capacity and insulation class. Generic transformers often run undersized VA ratings, causing thermal overload and premature failure — especially on systems with multiple 24V accessories.
• Install difficulty: 2/5 — De-energize the unit at the disconnect and breaker before beginning. Tools needed: multimeter, flathead and Phillips screwdrivers, wire stripper. Always confirm 24VAC output after installation before closing the panel. If fuses continue to blow, trace for a short in the low-voltage wiring loop.
• Warranty: 1-year OEM factory warranty. In-stock units ship same business day from our warehouse when ordered by cutoff time.

Compatibility: Designed as the direct OEM replacement for the Carrier PH1PNB036000AAAA packaged heat pump unit. The multi-tap primary (208/240/480V) makes this transformer suitable across varied commercial and residential supply voltages. Verify your unit's data plate voltage configuration before wiring. Have a fitment question? Our HVAC parts specialists confirm compatibility before you order — contact us today.