{"product_id":"carrier-c4850c50ak03661-transformer-h302a1","title":"OEM Carrier Transformer 40VA 120V to 24V for C4850C50AK03661 | National HVAC Parts","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V–24V for Model C4850C50AK03661\u003c\/h1\u003e\u003cp\u003eThis is the OEM factory-replacement transformer (part number \u003cstrong\u003eHT01BD236\u003c\/strong\u003e) for the \u003cstrong\u003eCarrier C4850C50AK03661\u003c\/strong\u003e packaged unit. The transformer steps down line voltage (120V) to the 24V signal voltage that powers your thermostat, control board, contactor coil, and all low-voltage control circuits. When this transformer fails, the entire control circuit goes dead — the thermostat displays nothing, the system won't respond to any call for heating or cooling, and no safety controls can operate. It is often the first component to check when a unit shows zero low-voltage activity.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01BD236 | Screw-terminal or quick-connect leads (verify against your existing unit)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers are wound and insulated to Carrier's exact VA and impedance specifications. Undersized or off-tolerance generic transformers can overheat, blow the 3A fuse on the control board, or damage downstream components — making a $30 repair into a $150+ problem.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the breaker and confirm zero voltage with a multimeter before touching any terminals. Tools needed: flathead and Phillips screwdrivers, multimeter, wire stripper. Photograph all wire connections before disconnecting. Replace the inline fuse if blown.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty. Orders placed before cutoff ship same business day from our warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed specifically for the \u003cstrong\u003eCarrier C4850C50AK03661\u003c\/strong\u003e commercial\/residential packaged unit. Always verify your existing transformer's VA rating and lead configuration against your unit's wiring diagram before ordering. Our parts specialists are available to confirm fitment — contact us before you order if you have any questions.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909828759923,"sku":"CARRIE-C4850C50AK03661-TRANSFORMER-HT01BD236","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909828792691,"sku":"CARRIE-C4850C50AK03661-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_408c3ad8-361f-4bdb-9c4e-13a73bf902bb.jpg?v=1782938875","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c4850c50ak03661-transformer-h302a1","provider":"National HVAC Parts","version":"1.0","type":"link"}