{"product_id":"carrier-c4850c48ay05051-transformer-h302a1","title":"OEM Carrier Transformer 40VA 120V-24V for C4850C48AY05051","description":"\u003ch1\u003eOEM Carrier Control Transformer 40VA for Model C4850C48AY05051\u003c\/h1\u003e\u003cp\u003eThis OEM replacement transformer (part# \u003cstrong\u003eHT01BD236\u003c\/strong\u003e) is the factory-specified step-down transformer for the \u003cstrong\u003eCarrier C4850C48AY05051\u003c\/strong\u003e packaged unit. The transformer converts 120V line voltage to the 24V AC signal that powers your thermostat, control board, contactor coil, and all low-voltage control circuits. When it fails, the entire control circuit goes dark — the thermostat goes blank, the system stops responding to calls for heating or cooling, and in some cases a blown fuse or tripped breaker on the secondary side is the first clue. Replacing this OEM unit restores full low-voltage function quickly and reliably.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated | Primary: 120V AC | Secondary: 24V AC | Factory-matched impedance and thermal protection for Carrier C4850C48AY05051 packaged units\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers (HT01BD236) feature factory-calibrated VA ratings and built-in thermal cutoffs that match Carrier's control board draw exactly. Generic transformers often run undersized, causing overheating and premature failure under full low-voltage load.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect all power before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Confirm 24V output on secondary terminals before reconnecting control wiring. Always discharge and verify zero voltage before handling.\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 Designed specifically for the Carrier \u003cstrong\u003eC4850C48AY05051\u003c\/strong\u003e packaged unit. Verify primary voltage (120V) and VA rating on your unit's data plate before ordering. OEM part number \u003cstrong\u003eHT01BD236\u003c\/strong\u003e cross-references directly to this model. Our fitment team is available to confirm compatibility before you order — don't let a failed transformer take your system offline any longer than necessary.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909876142451,"sku":"CARRIE-C4850C48AY05051-TRANSFORMER-HT01BD236","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909876175219,"sku":"CARRIE-C4850C48AY05051-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_c6eab062-32ab-463c-905f-88168f2edfb3.jpg?v=1782939269","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c4850c48ay05051-transformer-h302a1","provider":"National HVAC Parts","version":"1.0","type":"link"}