{"product_id":"carrier-subclr50hj440478-transformer-h30291","title":"OEM Carrier Transformer 40VA 208\/240V–24V for SUBCLR50HJ440478","description":"\u003ch1\u003eOEM Carrier 40VA Control Transformer 208\/240V to 24V — HT01BD209 for Model SUBCLR50HJ440478\u003c\/h1\u003e\u003cp\u003eThis OEM Carrier control transformer (part number \u003cstrong\u003eHT01BD209\u003c\/strong\u003e) is the factory-specified replacement for the \u003cstrong\u003eSUBCLR50HJ440478\u003c\/strong\u003e unit. The transformer steps down 208\/240V line voltage to the 24V signal used by your thermostat, control board, contactor coil, and all low-voltage safety controls. When this component fails, the result is total silence — no thermostat response, no call for heat or cooling, and no system operation of any kind. A failed or shorted transformer is also a common cause of blown 3A control fuses and tripped secondary circuits.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated capacity | Primary: 208\/240V | Secondary: 24V | 50\/60Hz dual frequency | Class 2 control transformer\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e The OEM HT01BD209 is wound and potted to Carrier's exact VA and impedance tolerances. Undersized aftermarket transformers can run hot, trip thermal cutoffs, or fail to sustain voltage under full control-circuit load — leading to nuisance lockouts.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Always disconnect power at the breaker before servicing. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter (verify 24V output after install). Label and photograph all low-voltage wiring before disconnecting. Primary wires are typically black (208V tap) and white; secondary outputs are red and common.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty. Ships same business day from our warehouse. Replaces superseded part numbers HT01BD207, HT01CN232, and 9076-00.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed for Carrier model \u003cstrong\u003eSUBCLR50HJ440478\u003c\/strong\u003e. Always verify primary voltage (208V vs 240V) on your unit's data plate to confirm correct tap wiring before installation. Compatible with both 50Hz and 60Hz applications. Questions about fitment? Our HVAC parts team verifies compatibility before you order — order with confidence and get it shipped today.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62640288465267,"sku":"CARRIE-SUBCLR50HJ440478-TRANSFORMER-HT01BD209","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62640288498035,"sku":"CARRIE-SUBCLR50HJ440478-TRANSFORMER-HT01BD209-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-HT01BD209_87f897ff-64a2-4bfa-b500-fa69c5a12f9b.jpg?v=1782942459","url":"https:\/\/nationalhvacparts.com\/products\/carrier-subclr50hj440478-transformer-h30291","provider":"National HVAC Parts","version":"1.0","type":"link"}