OEM Carrier Control Transformer 75VA 208/240/480V → 24VAC for Model PH3PNA030000AA

This OEM Carrier control transformer (part HT01BD242) is the factory-specified replacement for the Carrier PH3PNA030000AA packaged heat pump unit. The transformer steps down high-voltage line power (208, 240, or 480V primary) to the 24VAC signal required by your thermostat, control board, contactor coil, and all low-voltage safety circuits. When this transformer fails, the entire control circuit goes dead — your thermostat goes blank, the system won't respond to any call for heating or cooling, and fuses or breakers may trip repeatedly. Replacing it with the correct OEM unit restores full system operation immediately.

• Specs: Input (Primary): 208V / 240V / 480V multi-tap | Output (Secondary): 24VAC | Power Rating: 75VA | Frequency: 50/60Hz | Mount Type: Foot mount | OEM Part #: HT01BD242
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and voltage tolerances. Generic transformers can run under-rated VA, causing coil overheating, nuisance tripping of the control fuse, and premature failure of downstream components like contactors and control boards.
• Install Difficulty: 3/5 — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, multimeter, wire stripper, and needle-nose pliers. Label and photograph all low-voltage wiring before disconnecting. Verify primary tap selection matches your supply voltage before energizing. Always replace the 3A or 5A control fuse if it has blown.
• Warranty: 1-year OEM manufacturer warranty. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Engineered as a direct OEM replacement for Carrier model PH3PNA030000AA packaged heat pump units. Confirm your unit's supply voltage (208V, 240V, or 480V) and select the correct primary tap on the transformer upon installation. Cross-references OEM part number HT01BD242. Questions about fitment? Our HVAC parts specialists verify compatibility before you order — contact us today.