OEM Carrier Control Transformer 75VA 208/240/480V to 24VAC — HT01BD242 for Model PH1PNB048000AAAA

This is the factory OEM replacement control transformer for the Carrier PH1PNB048000AAAA packaged heat pump unit. The transformer steps high-line voltage (208, 240, or 480V primary) down to the 24VAC signal voltage required to power the entire low-voltage control circuit — including the thermostat, contactor coils, relay boards, and safety switches. When this transformer fails, the entire system goes dark: no thermostat response, no staging, no call-for-heat or cool — nothing works. A failed transformer is often caused by a shorted control wire, a faulty component drawing excess current, or simple end-of-life degradation. Always diagnose and clear the root cause before installing the replacement.

• Specs: 75VA power rating | Primary input: 208 / 240 / 480VAC | Secondary output: 24VAC | Frequency: 50/60Hz | Foot-mount configuration | OEM Part Number: HT01BD242
• OEM vs Generic: This is the genuine Carrier factory part, wound to exact VA and voltage tolerances. Generic transformers frequently run undersized on VA capacity, causing thermal overload trips under peak control-circuit demand and premature failure.
• Install difficulty: 3/5 — Requires shutting off all power at the disconnect and breaker before any work. Tools needed: multimeter (verify primary voltage and confirm 24VAC output after install), wire stripper, screwdrivers, needle-nose pliers. Always check for shorted low-voltage wiring before energizing — a dead short will blow the new transformer immediately.
• Warranty: 1-year OEM factory warranty against defects. In stock and ships same business day from our NationalHVACParts.com warehouse.

Compatibility: Direct OEM replacement for Carrier model PH1PNB048000AAAA packaged heat pump units. The 75VA rating and multi-tap primary (208/240/480V) make this transformer applicable across a wide range of Carrier, Bryant, Payne, and ICP family packaged and split-system equipment — always verify the OEM part number on your existing transformer before ordering. Questions about fitment? Our HVAC parts specialists confirm compatibility before you buy.