{"product_id":"carrier-ph1pnb042000aaaa-transformer-h3025m","title":"OEM Carrier Transformer 75VA 208\/240\/480V–24V for PH1PNB042000AAAA","description":"\u003ch1\u003eOEM Carrier Control Transformer 75VA 208\/240\/480V to 24V for Model PH1PNB042000AAAA\u003c\/h1\u003e\u003cp\u003eThis OEM Carrier transformer (part #HT01BD242) is the factory-specified replacement for the \u003cstrong\u003eCarrier PH1PNB042000AAAA\u003c\/strong\u003e heat pump system. The control transformer steps down the high-voltage supply (208\/240\/480V primary) to a safe 24VAC secondary signal that powers your thermostat, contactor coil, control board, and all low-voltage safety circuits. When this transformer fails, the entire control circuit goes dark — your thermostat goes blank, the system refuses to respond to any call for heating or cooling, and no error codes can even be generated. A failed transformer is often misdiagnosed as a control board failure, so always confirm 24VAC at the secondary terminals before replacing any other component.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 75VA power rating | Primary voltage: 208\/240\/480V multi-tap | Secondary voltage: 24VAC | Frequency: 50\/60Hz | Foot-mount configuration | OEM Part #HT01BD242\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This is the genuine Carrier factory OEM part, engineered to exact VA rating and insulation class. Generic transformers frequently underperform at rated load, causing voltage sag that triggers nuisance lockouts and premature contactor coil failure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Shut off all power at the disconnect and breaker panel before starting. Tools needed: multimeter, flathead and Phillips screwdrivers, wire stripper, needle-nose pliers. Label and photograph all low-voltage wiring before disconnecting. Verify 24VAC output at secondary terminals after installation before closing the panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e OEM manufacturer warranty included. In-stock units ship same business day from our warehouse — order by 3 PM local time.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed for the Carrier \u003cstrong\u003ePH1PNB042000AAAA\u003c\/strong\u003e heat pump packaged unit. The HT01BD242 multi-tap primary (208\/240\/480V) makes it suitable across a wide range of Carrier, Bryant, and Payne commercial and residential platforms — always verify your unit's supply voltage and VA requirement on the data plate before ordering. Our fitment team is available to confirm compatibility before you buy.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62641577427315,"sku":"CARRIE-PH1PNB042000AAAA-TRANSFORMER-HT01BD242","price":70.2,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62641577460083,"sku":"CARRIE-PH1PNB042000AAAA-TRANSFORMER-HT01BD242-GEN","price":23.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-HT01BD242_238b7773-aa13-4d67-bf47-7862fcdd5d88.jpg?v=1782943219","url":"https:\/\/nationalhvacparts.com\/products\/carrier-ph1pnb042000aaaa-transformer-h3025m","provider":"National HVAC Parts","version":"1.0","type":"link"}