{"product_id":"carrier-c4850c50ay04151-transformer-h302a1","title":"OEM Carrier 40VA Transformer 120V-24V for C4850C50AY04151","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer for Model C4850C50AY04151\u003c\/h1\u003e\u003cp\u003eThis OEM control transformer (part# \u003cstrong\u003eHT01BD236\u003c\/strong\u003e) is the factory-specified replacement for the \u003cstrong\u003eCarrier C4850C50AY04151\u003c\/strong\u003e packaged unit. The transformer steps down 120V primary voltage to 24V to power the low-voltage control circuit — including the thermostat, contactor coil, and all control board logic. When the transformer fails, the entire control circuit goes dead: the thermostat displays nothing, relays won't pull in, and the system will not respond to any call for heating or cooling. A blown secondary fuse or burnt winding smell are the most common failure indicators.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated | 120V primary \/ 24V secondary | OEM part number HT01BD236 | Factory-matched winding tolerance for stable control voltage\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers like this HT01BD236 are wound to exact VA and voltage specifications for the Carrier C4850C50AY04151 control circuit. Generic units often run undersized VA ratings, causing voltage sag under load that leads to erratic relay behavior and premature board failure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the disconnect box and confirm zero voltage with a multimeter before handling. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Note wire color and terminal labeling before disconnecting the old unit.\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 NationalHVACParts.com warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed specifically for the Carrier \u003cstrong\u003eC4850C50AY04151\u003c\/strong\u003e packaged unit. Always verify primary voltage (120V) and VA rating on your unit's data plate before ordering. If your 24V fuse keeps blowing after transformer replacement, check for shorted control wiring downstream before installing the new part. Our fitment team is available to confirm compatibility before you order — no guesswork required.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909809787251,"sku":"CARRIE-C4850C50AY04151-TRANSFORMER-HT01BD236","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909809820019,"sku":"CARRIE-C4850C50AY04151-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_1959d015-853b-45e7-9520-1e1a42a85204.jpg?v=1782899577","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c4850c50ay04151-transformer-h302a1","provider":"National HVAC Parts","version":"1.0","type":"link"}