{"product_id":"carrier-c4850c48z8090610-transformer-h302a1","title":"OEM Carrier Transformer 40VA 120V\/24V for C4850C48Z8090610","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer for Model C4850C48Z8090610\u003c\/h1\u003e\u003cp\u003eThis OEM control transformer (part# \u003cstrong\u003eHT01BD236\u003c\/strong\u003e) is the factory-specified replacement for the \u003cstrong\u003eCarrier C4850C48Z8090610\u003c\/strong\u003e packaged unit. The transformer steps down 120V line voltage to the 24V signal that powers your thermostat, contactor coils, and control board. When it fails, the entire control circuit goes dead — the thermostat goes blank, the system stops responding to calls for heating or cooling, and nothing operates. If you have 120V at the primary but no 24V at the secondary, this transformer is the culprit.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | 120V primary \/ 24V secondary | OEM part number HT01BD236 | Factory-matched output for stable control circuit voltage\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers are wound to exact VA and voltage tolerances for the Carrier C4850C48Z8090610 control board. Undersized or off-spec generic transformers can overheat, trip the built-in thermal fuse, or deliver unstable 24V — causing erratic lockouts and shortened board life.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the breaker and verify zero voltage before touching any terminals. Tools needed: multimeter, flathead and Phillips screwdrivers, wire nuts or spade connectors. Photograph all wiring before removal. The thermal fuse on a failed transformer is not resettable — full replacement is always required.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty. In stock and ships same business day from our warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Engineered specifically for the \u003cstrong\u003eCarrier C4850C48Z8090610\u003c\/strong\u003e packaged unit. Always verify the 120V\/24V rating and VA requirement on your unit's data plate before ordering. If you're unsure of fitment, our HVAC parts specialists can confirm compatibility before you buy — no guesswork required.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909868671347,"sku":"CARRIE-C4850C48Z8090610-TRANSFORMER-HT01BD236","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909868704115,"sku":"CARRIE-C4850C48Z8090610-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_6409115f-8619-46b3-a0da-b529372f0484.jpg?v=1782940075","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c4850c48z8090610-transformer-h302a1","provider":"National HVAC Parts","version":"1.0","type":"link"}