{"product_id":"carrier-c4850c50ak02751-transformer-h302a1","title":"OEM Carrier Transformer 40VA 120V to 24V for C4850C50AK02751 | National HVAC Parts","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V–24V for Model C4850C50AK02751\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement transformer (part number \u003cstrong\u003eHT01BD236\u003c\/strong\u003e) for the \u003cstrong\u003eCarrier C4850C50AK02751\u003c\/strong\u003e packaged unit. The transformer steps down 120V line voltage to 24V to power the entire low-voltage control circuit — including the thermostat, contactor coil, and control board. When this component fails, absolutely nothing responds: the thermostat goes blank, the system won't call for heating or cooling, and the unit sits completely unresponsive. A failed transformer is one of the most common causes of a total system lockout and is often misdiagnosed as a control board failure.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | 120V primary \/ 24V secondary | Class 2 control circuit transformer | OEM part number HT01BD236 | Factory-matched output voltage ±2%\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This OEM unit is wound to Carrier's exact VA and voltage specifications, ensuring stable 24V output under full control circuit load. Generic transformers frequently run under-rated, 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 — Disconnect all power before beginning. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Verify 24V output at secondary terminals after installation before restoring full power. Always check for a shorted control circuit wire that may have caused the original failure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects in materials and workmanship. Ships same business day from our stocked warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Direct OEM replacement for Carrier model \u003cstrong\u003eC4850C50AK02751\u003c\/strong\u003e packaged units. Confirm your existing transformer's VA rating and primary\/secondary voltages on the data plate before ordering. Our parts specialists are available to verify fitment — order with confidence and receive fast same-day shipping.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909833085299,"sku":"CARRIE-C4850C50AK02751-TRANSFORMER-HT01BD236","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909833118067,"sku":"CARRIE-C4850C50AK02751-TRANSFORMER-HT01BD236-GEN","price":18.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-HT01BD236_a35a7eca-1f5d-49f8-a34f-4981a67a93fc.jpg?v=1782938862","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c4850c50ak02751-transformer-h302a1","provider":"National HVAC Parts","version":"1.0","type":"link"}