{"product_id":"tempstar-40va-transformer-for-thb09r50rta-277v-to-24v-control-ships-today","title":"Tempstar 40VA Transformer for THB09R50RTA — 277V to 24V Control | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis is the genuine OEM 40VA control transformer for the Tempstar THB09R50RTA, stepping 277V line voltage down to the 24V required by the unit's control circuit (OEM 1091226, TRANS 277\u0026gt;24 40VA S). This listing also covers the related 24V control relays used in this chassis — 1053004 (RELAY 24V X) and 1060940 (RELAY 24V DPST X). The transformer powers the thermostat, relays, and control board; when it fails, the entire low-voltage side goes dead. A 40VA rating provides ample headroom for the unit's control loads. A burned-out or shorted transformer is a common cause of a completely unresponsive unit even when high-voltage power is present.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpec\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003e1091226 (transformer)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRelated Parts\u003c\/td\u003e\n\u003ctd\u003e1053004 (24V relay), 1060940 (24V DPST relay)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eStep-Down Control Transformer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Voltage\u003c\/td\u003e\n\u003ctd\u003e277V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Voltage\u003c\/td\u003e\n\u003ctd\u003e24V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRating\u003c\/td\u003e\n\u003ctd\u003e40VA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eTempstar \/ Heil \/ ICP\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDirect-fit replacement for the Tempstar THB09R50RTA PTAC chassis configured for 277V service. The same 40VA 277V-to-24V transformer is used across matching ICP, Heil, and Comfortmaker PTAC units. Verify your supply voltage is 277V before ordering.\u003c\/p\u003e\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety First\u003c\/strong\u003e — Disconnect 277V power at the breaker and verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the control-area service panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph the primary (line) and secondary (24V) wiring before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unbolt the transformer from its bracket and disconnect both windings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new transformer, land the 277V primary and 24V secondary leads per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm 24V across the secondary with a multimeter.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eNo 24V control voltage at the thermostat or relays\u003c\/li\u003e\n\u003cli\u003eUnit completely dead despite line power present\u003c\/li\u003e\n\u003cli\u003eBurnt smell or visibly scorched transformer\u003c\/li\u003e\n\u003cli\u003eTripping breaker on a shorted secondary\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\u003cp\u003eShips same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"Tempstar","offers":[{"title":"Direct Replacement","offer_id":63021638025587,"sku":"1053004-GEN","price":39.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048412856691,"sku":"1053004","price":50.7,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-1053004_1e2c59ee-2897-45e7-97b4-db423b5328a6.jpg?v=1782958604","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-40va-transformer-for-thb09r50rta-277v-to-24v-control-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}