{"product_id":"castair-pressure-switch-95-125-psi-on-off-w-unloader-psl1x","title":"Castair Pressure Switch 95-125 PSI On\/Off w\/unloader PSL1X","description":"\u003cp\u003eThe Castair PSL1X is a 95-125 PSI pressure switch with an integrated unloader valve. It is the standard replacement switch for belt-drive, single-phase piston compressors running in the standard shop pressure range. The unloader valve is the key feature — when the motor shuts off at 125 PSI, the unloader bleeds the residual pressure from the pump discharge line so the motor can restart at 95 PSI against a free-spinning pump. Without this function, a single-phase motor tries to start under load, which trips thermal overloads and burns start capacitors. The PSL1X at $39.85 is inexpensive insurance for a motor that costs much more to replace.\u003c\/p\u003e\n\n\u003ch2\u003eHow the Unloader Works\u003c\/h2\u003e\n\u003cp\u003eWhen the switch opens at 125 PSI cut-out, it simultaneously opens the unloader valve. Air bleeds back from the discharge line through a small copper tube to the pump intake. This drops the pressure on the pump head to near-zero. When pressure falls to 95 PSI and the switch closes to restart the motor, the pump starts against atmospheric pressure on the discharge side rather than against 100+ PSI of trapped air. The motor accelerates to speed quickly, the check valve closes, and compression resumes normally. This cycle happens dozens of times per day on a busy shop compressor, and the unloader is what makes it reliable long-term.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating range:\u003c\/strong\u003e 95 PSI cut-in \/ 125 PSI cut-out\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnloader valve:\u003c\/strong\u003e Integrated — bleeds head pressure at every shutdown cycle\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCorrosion resistant cover:\u003c\/strong\u003e Weather and moisture resistant for shop installation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEasy to adjust:\u003c\/strong\u003e Differential and cut-out pressure field-adjustable\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUL\/CSA listed:\u003c\/strong\u003e Commercial electrical safety listed\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eConfiguration Options at 95-125 PSI\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePSL1\u003c\/strong\u003e — No unloader ($36.31)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePSL1X\u003c\/strong\u003e — With unloader, no on\/off lever ($39.85) — this unit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePSL1MIX\u003c\/strong\u003e — With unloader and on\/off lever ($40.73)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePSL4MIX\u003c\/strong\u003e — With unloader, on\/off, and four-way valve\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhen Do You Need This vs. Stepping Up or Down?\u003c\/h2\u003e\n\u003cp\u003eThe PSL1X is correct for any single-phase belt-drive compressor running 95-125 PSI without a built-in on\/off lever on the existing switch. If your existing switch had an on\/off lever, order the PSL1MIX instead. If you are running a 145-175 PSI system, this is the wrong range — order the PSH1X. If your system has a four-port manifold connection, check the PSL4MIX. For most single-phase shop compressors in the 95-125 PSI range, the PSL1X is the right standard replacement.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e PSL1X\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Castair (Cast Air)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePressure range:\u003c\/strong\u003e 95-125 PSI\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnloader valve:\u003c\/strong\u003e Yes, integrated\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOn\/Off switch:\u003c\/strong\u003e No\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCertifications:\u003c\/strong\u003e UL\/CSA listed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCover:\u003c\/strong\u003e Corrosion resistant\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrice:\u003c\/strong\u003e $39.85\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e1x Castair PSL1X pressure switch with integrated unloader valve\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhy Buy From Air Compressor Factory Direct?\u003c\/h3\u003e\n\u003cp\u003eWe stock the complete Castair component lineup. The PSL1X is a direct OEM-equivalent replacement — not a generic aftermarket switch that may have different port sizing or wiring configuration. Free shipping on qualifying orders. Call our tech line if you need help confirming the right switch for your compressor.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCall 866-217-0063 for quick answers and help!\u003c\/strong\u003e\u003c\/p\u003e","brand":"Cast Air","offers":[{"title":"Default Title","offer_id":53342575231189,"sku":"PSL1X","price":73.84,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0622\/8466\/0949\/files\/PRESSURE-SWITCHES_11a01ba1-676b-4b31-9fc6-e949c6e6714b.jpg?v=1772652806","url":"https:\/\/aircompressorfactorydirect.com\/products\/castair-pressure-switch-95-125-psi-on-off-w-unloader-psl1x","provider":"Air Compressor Factory Direct","version":"1.0","type":"link"}