{"product_id":"tjernlund-products-ps1505","title":"Tjernlund Products PS1505 Prover Switch","description":"\u003cp\u003eThe \u003cstrong\u003eTjernlund Products PS1505 Prover Switch\u003c\/strong\u003e is a critical safety interlock designed specifically for \u003cstrong\u003eTjernlund Auto-Draft inducers\u003c\/strong\u003e. As a veteran-grade \u003cstrong\u003efan proving safety switch\u003c\/strong\u003e, it monitors vacuum pressure within the fan housing to verify that the inducer is operating at peak performance before allowing the burner circuit to fire. This \u003cstrong\u003eSPST air pressure switch\u003c\/strong\u003e features a non-adjustable set point of 0.05\" ± 0.02\" W.C. (increasing vacuum), ensuring precise response times and preventing combustion in the event of motor or wheel failure. The unit is housed in a durable \u003cstrong\u003ezinc-plated steel\u003c\/strong\u003e enclosure to withstand harsh boiler room environments and is rated for \u003cstrong\u003e15A non-inductive\u003c\/strong\u003e loads up to 277 VAC.\u003c\/p\u003e\n\n\u003cp\u003eFor proper field installation, the \u003cstrong\u003ePS1505\u003c\/strong\u003e must be mounted with the diaphragm in a vertical position to maintain calibration. It is compatible with 24V, 115V, and 277V burner circuits but is not suitable for millivolt gas valves. Use this high-performance \u003cstrong\u003eprover switch\u003c\/strong\u003e to satisfy national mechanical codes and maintain system integrity in residential and light commercial HVAC applications.\u003c\/p\u003e\n\n\u003cstrong\u003eKey Benefits\u003c\/strong\u003e\n\u003cul\u003e\n  \u003cli\u003eEnsures safety by deactivating burners instantly if the inducer fan fails or housing pressure drops.\u003c\/li\u003e\n  \u003cli\u003eRugged zinc-plated steel construction provides long-term reliability in industrial and commercial HVAC settings.\u003c\/li\u003e\n  \u003cli\u003eFixed set point (0.03\" to 0.07\" W.C.) eliminates field calibration errors and ensures consistent \u003cstrong\u003efan proving\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003eVersatile electrical ratings (125 VA to 300 VA pilot duty) allow for broad compatibility across \u003cstrong\u003edraft inducer\u003c\/strong\u003e models.\u003c\/li\u003e\n  \u003cli\u003eIncluded mounting hardware simplifies vertical installation for field technicians.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cstrong\u003eCommon Questions\u003c\/strong\u003e\n\u003cp\u003e\u003cstrong\u003eIs the PS1505 compatible with millivolt systems?\u003c\/strong\u003e\u003cbr\u003e\nNo, this switch is designed for 24V to 277V circuits and is not compatible with millivolt gas valves.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat happens if the diaphragm is not mounted vertically?\u003c\/strong\u003e\u003cbr\u003e\nThe set point is factory-calibrated for vertical mounting; installing it horizontally will shift the pressure threshold and may cause the system to fail \"proof\" or cycle incorrectly.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCan I use this switch with non-Tjernlund inducers?\u003c\/strong\u003e\u003cbr\u003e\nThe PS1505 is specifically engineered for \u003cstrong\u003eTjernlund Auto-Draft\u003c\/strong\u003e series equipment; using it on other brands may lead to compatibility issues with 1\/4\" compression fittings or pressure ranges.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong style=\"color: red;\"\u003eThis item is not eligible for free shipping.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eDisclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.\u003c\/p\u003e","brand":"Tjernlund Products","offers":[{"title":"Default Title","offer_id":43465312338098,"sku":"PS1505","price":120.43,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1838\/2375\/files\/Pic_0cedfb50-8750-41b9-b3d9-09aba317d95a.png?v=1701811594","url":"https:\/\/www.gsistore.com\/products\/tjernlund-products-ps1505","provider":"GSIstore","version":"1.0","type":"link"}