{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3UG3501-1AL20","brand":"Siemens","brandSlug":"siemens","productSlug":"3UG3501-1AL20","canonicalUrl":"https://aoctrl.com/siemens/3UG3501-1AL20","factsUrl":"https://aoctrl.com/api/mcp/products/3UG3501-1AL20","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS monitoring relay, 3UG3501-1AL20, 22.5 mm, for level monitoring, 1 CO, sensitivity 5…100 kΩ, AC 230 V 50/60 Hz, screw connection.","salesMarkdown":"The Siemens SIRIUS 3UG3501-1AL20 is a 22.5 mm monitoring relay built for level detection — think pump-tank high/low, sump alarms, or any conductive liquid-level boundary where you need a simple on/off signal. It runs on AC control supply voltage in the 196–253 V range at 50 or 60 Hz, so it drops straight into a standard 230 V panel without a separate power supply. The adjustable sensitivity spans 5 to 100 kΩ — that covers most conductive liquids (water, weak acids, coolants) but won't trigger on high-resistance foams or dry contacts. Set the threshold with the front potentiometer; no programming tool needed. The single changeover contact (1 CO) handles the load directly for small contactors or PLC inputs, but if you're switching a motor starter, interpose a proper contactor — the relay itself isn't rated for heavy inductive inrush. The screw-type terminals accept solid or stranded wire from 20 to 14 AWG, and finely stranded with ferrule from 0.5 to 2.5 mm². Two conductors per terminal are allowed, which helps when daisy-chaining supply or looping probes. Strip length follows standard practice — about 8 mm — though the spec doesn't call it out explicitly. ## Where you'll use it This class of relay lives in control panels for water/wastewater, process tanks, or any vessel where you need to detect a liquid level and trigger a pump or alarm. The 22.5 mm housing clips onto DIN rail (screw and snap-on mounting,) and fits standard enclosure fill patterns. Depth is 100 mm, height 78 mm — leaves room for wiring ducts in a 200 mm deep cabinet.","metaTitle":"Siemens 3UG3501-1AL20 SIRIUS Monitoring Relay, Level, 22.5 m","metaDescription":"Siemens SIRIUS 3UG3501-1AL20 monitoring relay for level monitoring, 1 CO contact, adjustable sensitivity 5–100 kΩ, AC 230 V 50/60 Hz, screw terminals, current lifecycle stage.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Process / Temperature Controllers"],"specifications":{"Depth":"100 mm","Solid":"20 ... 14","Width":"22.5 mm","Height":"78 mm","Stranded":"20 ... 14","lifecycle_stage":"current","Fastening Method":"screw and snap-on mounting","Product Brand Name":"SIRIUS","at AWG cables solid":"2x (20 ... 14)","at 50 Hz rated value":"196 ... 253 V","at 60 Hz rated value":"196 ... 253 V","at AWG cables stranded":"2x (20 ... 14)","Adjustable Responsiveness":"Yes","Of The Control Supply Voltage":"AC","Type Of Electrical Connection":"screw-type terminals","reference code acc. to IEC 81346-2":"K","Finely Stranded With Core End Processing":"0.5 ... 2.5 mm²"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":null,"alternativesUrl":"https://aoctrl.com/api/mcp/products/3UG3501-1AL20/alternatives.json"},"ai":{"faq":[{"question":"What are the key ratings for this monitoring relay?","answer":"It operates on AC control supply voltage 196–253 V at 50/60 Hz, with adjustable sensitivity from 5 to 100 kΩ. It has one changeover contact (1 CO) and screw-type terminals accepting 20–14 AWG solid or stranded wire."},{"question":"What is the physical size and mounting method?","answer":"The housing is 22.5 mm wide, 78 mm high, and 100 mm deep. It mounts on DIN rail using a screw and snap-on mechanism."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3UG3501-1AL20","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/siemens/3UG3501-1AL20 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}