{"product_id":"carrier-fc4dnb042000aaaa-transformer-h3hwwy","title":"OEM Carrier Transformer 40VA 120V-24V for FC4DNB042000AAAA","description":"\u003ch1\u003eOEM Carrier Transformer 40VA 120V to 24V for Model FC4DNB042000AAAA\u003c\/h1\u003e\u003cp\u003eThis OEM step-down transformer (part number \u003cstrong\u003eHT01CN241\u003c\/strong\u003e) is the factory-specified replacement for the \u003cstrong\u003eCarrier FC4DNB042000AAAA\u003c\/strong\u003e fan coil unit. The transformer converts 120V line voltage down to the 24V AC signal that powers the entire control circuit — including the thermostat, contactor coil, and integrated control board. When this component fails, nothing in the system responds: the thermostat goes dark, the blower won't energize, and the unit sits completely dead despite line voltage being present at the unit.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA capacity | 120V primary input | 24V secondary output | Direct OEM replacement for part number HT01CN241 | Factory-matched impedance and insulation class\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This factory OEM transformer is wound to exact VA and voltage tolerances required by the FC4DNB042000AAAA control circuit. Undersized or off-tolerance generic transformers can overheat, trip thermal cutoffs prematurely, or deliver insufficient current to hold contactor coils closed — causing intermittent lockouts that are difficult to diagnose.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Shut off all power at the disconnect and breaker before starting. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Photograph all wiring connections before removing the old transformer. Verify 24V output with a multimeter after installation before restoring full system power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty against defects. Ships same business day from our HVAC-dedicated warehouse when ordered before 3 PM local time.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed specifically for the \u003cstrong\u003eCarrier FC4DNB042000AAAA\u003c\/strong\u003e fan coil unit. Always confirm the OEM part number HT01CN241 against your unit's wiring diagram or data plate before ordering. Our parts specialists are available to verify fitment — contact us before you order if you have any questions. In stock and ready to ship today.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62909524902259,"sku":"CARRIE-FC4DNB042000AAAA-TRANSFORMER-HT01CN241","price":47.25,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62909524935027,"sku":"CARRIE-FC4DNB042000AAAA-TRANSFORMER-HT01CN241-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-HT01CN241_8a36e0d9-2396-4acb-8fc5-86d18e174b40.jpg?v=1782939563","url":"https:\/\/nationalhvacparts.com\/products\/carrier-fc4dnb042000aaaa-transformer-h3hwwy","provider":"National HVAC Parts","version":"1.0","type":"link"}