OEM Carrier Control Transformer 75VA 208/240/480V to 24V for Model PH3GNAA30000AA

This OEM control transformer is the factory-specified replacement for the Carrier PH3GNAA30000AA packaged unit. The transformer steps down high-voltage primary power (208/240/480V) to the 24VAC signal required by the low-voltage control circuit — powering your thermostat, contactor coil, and all safety control boards. When it fails, the entire control circuit goes dark: the thermostat loses power, the system won't respond to any call for heating or cooling, and you may notice a faint burning smell or visible scorch marks on the transformer body.

• Specs: 75VA rating | Primary: 208/240/480V | Secondary: 24VAC | 50/60 Hz | Foot-mount configuration | OEM Part #HT01BD242
• OEM vs Generic: This is a genuine Carrier OEM transformer wound to exact factory VA and voltage tolerances. Undersized or off-tolerance aftermarket units can overheat under full control-circuit load, tripping internal breakers or failing prematurely — especially on multi-stage systems drawing higher 24V current.
• Install difficulty: 3/5 — Always disconnect main power at the disconnect box before servicing. Tools needed: multimeter (to confirm 0V before touching terminals), flathead and Phillips screwdrivers, wire stripper, needle-nose pliers. Label all 24V low-voltage wires before removal. Torque terminals firmly to avoid loose connections that cause overheating.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Designed as the direct OEM replacement for Carrier model PH3GNAA30000AA packaged units. The 75VA rating and multi-tap primary (208/240/480V) make this transformer suitable for commercial and light-commercial voltage configurations. Always verify your unit's data plate voltage before ordering. Have a question about fitment? Our HVAC parts specialists confirm compatibility before you buy — call or chat today.