{"product_id":"carrier-ph3znb042000ab-transformer-h30291","title":"OEM Carrier Control Transformer 40VA 208\/240V–24V — PH3ZNB042000AB","description":"\u003ch1\u003eOEM Carrier Control Transformer 40VA 208\/240V to 24V for Model PH3ZNB042000AB\u003c\/h1\u003e\u003cp\u003eThis OEM control transformer is the factory-specified replacement for the \u003cstrong\u003eCarrier PH3ZNB042000AB\u003c\/strong\u003e packaged HVAC unit. Its sole job is to step down the 208\/240V line voltage to the 24V signal that powers your thermostat, control board, gas valve, and every other low-voltage component in the system. When the transformer fails — due to a short, overload, or age — the entire control circuit goes dead: the thermostat goes blank, the unit won't respond to any call for heating or cooling, and you'll typically measure 0V at the 24V secondary terminals.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA capacity | 208\/240V primary input | 24V secondary output | 50\/60 Hz | OEM part number HT01BD209 | Replaces HT01BD207, HT01CN232, 9076-00\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers are wound and encapsulated to Carrier's exact VA and voltage tolerances. Undersized or off-tolerance generic units can cause nuisance lockouts, erratic thermostat behavior, or premature secondary component failures.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Shut off power at the disconnect and verify zero voltage with a multimeter before touching any wiring. Tools needed: flathead and Phillips screwdrivers, multimeter, wire stripper. Label all wires before disconnecting — the primary (line) and secondary (low-voltage) sides must not be swapped.\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 stocked warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Engineered for the Carrier \u003cstrong\u003ePH3ZNB042000AB\u003c\/strong\u003e packaged unit. Always verify your existing transformer's VA rating and primary voltage on the unit data plate before ordering to ensure a correct fit. Have a question? Our HVAC parts team confirms fitment before you buy — order with confidence and get it back up and running today.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62641334813043,"sku":"CARRIE-PH3ZNB042000AB-TRANSFORMER-HT01BD209","price":50.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62641334845811,"sku":"CARRIE-PH3ZNB042000AB-TRANSFORMER-HT01BD209-GEN","price":44.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-HT01BD209_e671964b-f0f3-45ec-a08f-f71571a4d7de.jpg?v=1775025760","url":"https:\/\/nationalhvacparts.com\/products\/carrier-ph3znb042000ab-transformer-h30291","provider":"National HVAC Parts","version":"1.0","type":"link"}