{"product_id":"carrier-ph3ppa042000aa-transformer-h3025m","title":"OEM Carrier Transformer 75VA 208\/240\/480V–24V for PH3PPA042000AA","description":"\u003ch1\u003eOEM Carrier 75VA Control Transformer HT01BD242 for Model PH3PPA042000AA\u003c\/h1\u003e\u003cp\u003eThis OEM Carrier transformer (part number \u003cstrong\u003eHT01BD242\u003c\/strong\u003e) is the factory-specified control circuit transformer for the \u003cstrong\u003eCarrier PH3PPA042000AA\u003c\/strong\u003e packaged heat pump unit. It steps down high-voltage primary power — 208, 240, or 480V — to a safe 24VAC secondary output that energizes the thermostat, control board, contactor coils, and all low-voltage safety circuits. When this transformer fails, the entire control circuit goes dead: the thermostat loses power, the unit won't respond to calls for heating or cooling, and no low-voltage components can operate. A failed transformer is often identified by a tripped internal fuse, a burnt smell at the transformer body, or 0VAC measured on the secondary terminals.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 75VA power rating | Primary input: 208\/240\/480V | Secondary output: 24VAC | Frequency: 50\/60Hz | Foot-mount configuration | OEM part number HT01BD242\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e This is a genuine Carrier OEM transformer wound to exact factory VA and voltage tolerances. Generic aftermarket transformers frequently run under-rated VA, causing premature thermal overload failure — especially in systems with multiple 24V accessory loads like zone boards or humidifiers.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 3\/5\u003c\/strong\u003e — Always disconnect power at the disconnect and breaker before servicing. Tools needed: multimeter (to verify 0V before touching), flathead and Phillips screwdrivers, wire stripper\/crimper, needle-nose pliers. Photograph all low-voltage wiring before disconnecting. Verify secondary output is 24–28VAC after installation before restoring full system power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM factory warranty. In-stock units ship same business day from our warehouse when ordered before cutoff.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Fits Carrier model \u003cstrong\u003ePH3PPA042000AA\u003c\/strong\u003e packaged heat pump unit. The multi-tap primary (208\/240\/480V) makes this transformer compatible across a wide range of commercial voltage configurations — confirm your supply voltage matches one of the primary taps before ordering. Questions about fitment? Our HVAC parts specialists verify compatibility before you buy.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62641344577907,"sku":"CARRIE-PH3PPA042000AA-TRANSFORMER-HT01BD242","price":70.2,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62641344610675,"sku":"CARRIE-PH3PPA042000AA-TRANSFORMER-HT01BD242-GEN","price":23.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-HT01BD242_54da7c95-fde9-497c-88ea-0ec729c815e4.jpg?v=1782943299","url":"https:\/\/nationalhvacparts.com\/products\/carrier-ph3ppa042000aa-transformer-h3025m","provider":"National HVAC Parts","version":"1.0","type":"link"}