{"product_id":"carrier-c48a603564-transformer-h301d7","title":"OEM Carrier Transformer 40VA 120V\/24V for C48A603564","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer HT01BD702 for Model C48A603564\u003c\/h1\u003e\u003cp\u003eThis is the OEM factory-specified control transformer (part number \u003cstrong\u003eHT01BD702\u003c\/strong\u003e) for the \u003cstrong\u003eCarrier C48A603564\u003c\/strong\u003e packaged unit. The transformer steps down 120V line voltage to 24V AC to power the entire low-voltage control circuit — including the thermostat, contactor coil, and control board. When this transformer fails, absolutely nothing responds: the thermostat goes dark, the system won't call for cooling or heating, and no fault codes appear because the control board itself has lost power.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated | Primary: 120V AC | Secondary: 24V AC | Factory-matched OEM replacement | Part number HT01BD702\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers are wound to exact VA and voltage tolerances required by Carrier's control circuit. Undersized or off-tolerance generic units can overheat, blow the secondary fuse, or fail to sustain voltage under full control circuit load — leading to nuisance lockouts and repeat failures.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Disconnect power at the breaker and confirm voltage is absent before beginning. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter. Photograph or label all wiring connections before removing the old transformer. Check and replace the 3A or 5A secondary fuse if blown — a failed fuse often indicates the transformer itself has failed.\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 as a direct OEM replacement for the \u003cstrong\u003eCarrier C48A603564\u003c\/strong\u003e packaged unit. Verify your existing transformer's VA rating and primary\/secondary voltages on the unit data plate or transformer label before ordering. Our fitment team is available to confirm compatibility prior to purchase — same-day shipping on all in-stock orders.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909724623219,"sku":"CARRIE-C48A603564-TRANSFORMER-HT01BD702","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909724655987,"sku":"CARRIE-C48A603564-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_3f0f4c73-bc78-47b0-8b1e-ef7f2c5fe408.jpg?v=1782940258","url":"https:\/\/nationalhvacparts.com\/products\/carrier-c48a603564-transformer-h301d7","provider":"National HVAC Parts","version":"1.0","type":"link"}