OEM Carrier Control Transformer 75VA 208/240/480V to 24VAC for Model PH2PNB042000AA

This OEM Carrier control transformer (part #HT01BD242) is the factory-specified replacement for the Carrier PH2PNB042000AA packaged heat pump unit. The transformer steps down high-voltage supply power (208, 240, or 480V primary) to the 24VAC secondary that energizes the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and all safety switches. When this transformer fails, the result is total control loss: the thermostat goes dark, the system won't respond to any call for heating or cooling, and you may measure 0VAC on the 24V secondary. A blown internal fuse or shorted secondary winding is the most common cause of failure.

• Specs: Primary Input: 208/240/480VAC | Secondary Output: 24VAC | Power Rating: 75VA | Frequency: 50/60Hz | Mount Style: Foot Mount | OEM Part #: HT01BD242
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and voltage specifications. Generic transformers may list the same ratings but often lack the thermal overload protection and tight winding tolerances required for reliable 24V control circuit performance in commercial packaged equipment.
• Install difficulty: 3/5 — Disconnect all power and verify zero voltage at the unit before beginning. Tools needed: multimeter, flathead and Phillips screwdrivers, wire labels or masking tape. Photograph all low-voltage wiring connections before disconnecting. Test secondary output voltage (should read 24–28VAC under no load) after installation before restoring the full system.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse when ordered by cutoff time.

Compatibility: Designed for the Carrier PH2PNB042000AA packaged heat pump unit. This transformer is also used across Carrier, Bryant, Payne, Tempstar, Heil, and Comfortmaker commercial packaged RTU platforms sharing the same 75VA 208/240/480V primary control transformer specification — always verify your unit's data plate voltage and VA rating before ordering. Our HVAC parts specialists are available to confirm fitment prior to purchase.