{"product_id":"carrier-c50a403564-transformer-h301d7","title":"OEM Carrier Transformer 40VA 120V\/24V for C50A403564","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer HT01BD702 for Model C50A403564\u003c\/h1\u003e\u003cp\u003eThis is the factory OEM replacement transformer for the \u003cstrong\u003eCarrier C50A403564\u003c\/strong\u003e commercial packaged unit. The transformer steps down 120V line voltage to the 24V signal required by your thermostat, control board, contactor coil, and every other low-voltage component in the system. When this part fails, absolutely nothing works — the thermostat goes dark, the contactor won't pull in, and the unit sits completely unresponsive. A failed transformer is often the first thing to check when a system appears totally dead with no fault codes.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e OEM Part Number HT01BD702 | 40VA rated | Primary: 120V | Secondary: 24V | Factory-matched to Carrier C50A403564 control circuit requirements\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This OEM transformer is wound to exact factory VA and voltage tolerances. Undersized or off-tolerance generic transformers can overheat, blow the 3A control fuse repeatedly, or deliver insufficient voltage to fire the gas valve or energize the contactor — causing intermittent callbacks and misdiagnosis.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Shut off all power before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Verify 0V at transformer primary before disconnecting leads. Label all wires before removal and confirm secondary output reads 24–28V AC after install.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects. In stock — ships same business day from our HVAC-dedicated warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed specifically for \u003cstrong\u003eCarrier C50A403564\u003c\/strong\u003e commercial rooftop\/packaged units using OEM part number HT01BD702. Always verify your existing transformer's VA rating and primary\/secondary voltages against your unit's wiring diagram before ordering. Our fitment team is available to confirm compatibility before you buy — no guesswork required.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909681566067,"sku":"CARRIE-C50A403564-TRANSFORMER-HT01BD702","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909681598835,"sku":"CARRIE-C50A403564-TRANSFORMER-HT01BD702-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-HT01BD702_f4b1c685-e10a-488d-9419-898fa9463868.jpg?v=1782940522","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c50a403564-transformer-h301d7","provider":"National HVAC Parts","version":"1.0","type":"link"}