{"product_id":"payne-pa3znb030000ac-transformer-h30291","title":"OEM Payne Transformer 40VA 120V-24V for PA3ZNB030000AC","description":"\u003ch1\u003eOEM Payne Control Transformer 40VA 120V\/24V for Model PA3ZNB030000AC\u003c\/h1\u003e\u003cp\u003eThis is the OEM factory-specified step-down transformer (part# \u003cstrong\u003eHT01BD209\u003c\/strong\u003e) for the \u003cstrong\u003ePayne PA3ZNB030000AC\u003c\/strong\u003e air conditioning system. The transformer converts 120V line voltage to the 24V signal used by your thermostat, contactor coil, and control board. When it fails, the entire control circuit goes dead — the thermostat goes blank, the system stops responding to calls for cooling, and no components operate. A failed transformer is one of the most commonly misdiagnosed HVAC problems, often confused with a bad thermostat or control board.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 40VA rated | 120V primary \/ 24V secondary | Class 2 output | Factory-matched impedance for Payne PA3ZNB030000AC control circuit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e The OEM HT01BD209 transformer is wound and rated to exact factory tolerances. Generic transformers often underperform at rated VA load, leading to voltage sag, nuisance tripping of the secondary fuse, and premature failure under full circuit demand.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Always disconnect power at the breaker before beginning work. Tools needed: flathead and Phillips screwdrivers, wire stripper, multimeter. Label all low-voltage wires before removal. Verify 24V output at secondary terminals before reassembling the unit.\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 and factory-matched for the Payne \u003cstrong\u003ePA3ZNB030000AC\u003c\/strong\u003e split-system air conditioner. Verify your existing transformer's VA rating and primary\/secondary voltage on the unit's data plate or wiring diagram before ordering. Not sure it fits? Our HVAC parts specialists confirm fitment before you buy — same-day shipping available on all in-stock orders.\u003c\/p\u003e","brand":"Payne","offers":[{"title":"OEM","offer_id":62908880781683,"sku":"PAYNE-PA3ZNB030000AC-TRANSFORMER-HT01BD209","price":34.95,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62908880814451,"sku":"PAYNE-PA3ZNB030000AC-TRANSFORMER-HT01BD209-GEN","price":30.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-HT01BD209_453bc8f8-95bd-4589-af51-439b722dd22c.jpg?v=1780718873","url":"https:\/\/nationalhvacparts.com\/products\/payne-pa3znb030000ac-transformer-h30291","provider":"National HVAC Parts","version":"1.0","type":"link"}