{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"Z-15HQ21-B","brand":"Omron","brandSlug":"omron","productSlug":"Z-15HQ21-B","canonicalUrl":"https://aoctrl.com/omron/Z-15HQ21-B","factsUrl":"https://aoctrl.com/api/mcp/products/Z-15HQ21-B","rawCanonicalId":null},"summary":{"shortDescription":"Omron Z-15HQ21-B, Z series general-purpose basic switch, SPDT, screw terminal, 15 A at 250 VAC, 4.2 mm mounting hole.","salesMarkdown":"## Form factor and what it actually is Omron's Z-15HQ21-B sits in the Z series of general-purpose basic switches — the classic snap-action limit switch used as a position-trip element on machine gates, conveyor end-stops, and door interlocks where a mechanical cam pushes the actuator and the contact snaps over. The body is a basic-switch form factor: a single-pole/double-throw (SPDT) contact set with screw terminals brought out the side for hard-wiring into a control panel or junction box, and a 4.2 mm mounting hole pattern for panel or bracket fastening. ## Headline ratings and what they decide The 15 A at 250 VAC rating on the SPDT contact set is the figure that decides fit for a 240 V single-phase motor starter aux circuit or a solenoid/valve coil driver — anything drawing more than 15 A continuous belongs on a contactor, not a limit switch. Inrush tolerance is asymmetric: the NC leg handles up to 30 A inrush, while the NO leg is rated for up to 15 A inrush, which matters when switching inductive loads like solenoid valves or motor starter coils where the closing surge runs well above the steady-state current. Mechanical switching is rated at 240 operations per minute maximum, with an electrical endurance floor of 500,000 operations — the mechanical figure is the duty ceiling a cam-driven application must respect, and the electrical figure is the wear budget over service life. ## Wiring it in Screw terminals accept standard stripped conductors and are the wiring side of the switch — the actuator side (lever, plunger, roller) is the part that sees the machine motion, so the panel-side wiring is straightforward but the actuator selection drives the actual trip behaviour. The 4.2 mm mounting holes fix the body to a bracket or panel face; correct mounting orientation keeps the actuator aligned with the cam or striker and avoids side-load that would wear the plunger early.","metaTitle":"Omron Z-15HQ21-B limit switch, SPDT, 15 A 250 VAC","metaDescription":"Omron Z-15HQ21-B Z series snap-action limit switch, SPDT, rated 15 A at 250 VAC with screw terminals. Quoted to order through independent distribution.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Limit Switches"],"specifications":{"title":"Z-15HQ21-B","Rated load":"15 A at 250 VAC","Switch type":"SPDT","description":"Z Series General Purpose Basic Switch|The most popular snap action limit switch","Terminal type":"Screw terminal","Inrush current":"Up to 30 A at NC, Up to 15 A at NO","lifecycle_stage":"current","Mounting hole size":"4.2 mm","Mechanical operations":"240 operations/minute max.","Electrical operations minimum":"500,000 operations","Mechanical operations minimums":"20 operations/minute max."}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/26be32fe58e32df2a0d0ad37fe87e994.pdf","sourceUrl":"https://automation.omron.com/en/us/products/family/Z-15"},"ai":{"faq":[{"question":"What is Z-15HQ21-B's listed rated load on this limit switch line?","answer":"15 A at 250 VAC on the SPDT contact set, per the headline ratings carried on this code."},{"question":"What is Z-15HQ21-B's listed switch type on this limit switch line?","answer":"SPDT — single-pole, double-throw — with screw terminal wiring."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/omron/Z-15HQ21-B","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/omron/Z-15HQ21-B when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}