{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3UG4512-2BR20","brand":"Siemens","brandSlug":"siemens","productSlug":"3UG4512-2BR20","canonicalUrl":"https://aoctrl.com/siemens/3UG4512-2BR20","factsUrl":"https://aoctrl.com/api/mcp/products/3UG4512-2BR20","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3UG4512-2BR20 phase monitoring relay, 160–690 V AC, 50/60 Hz, 3 A rated, 22.5 mm wide, snap-on mounting, IP20.","salesMarkdown":"## Phase monitoring relay for 160–690 V AC lines The Siemens 3UG4512-2BR20 is a SIRIUS phase monitoring relay that watches three-phase AC lines from 160 to 690 V at 50 or 60 Hz. It detects phase loss and incorrect phase sequence — the two most common supply faults that kill motors and drives — and drops its output contacts when the line condition goes out of spec. The relay has two changeover contacts rated 3 A at 250/400 V AC, enough to signal a PLC or drop out a contactor coil directly. The 160–690 V AC range covers low-voltage networks from 208 V to 600 V class without needing a separate voltage variant — one SKU handles 230/400 V and 480/577 V supplies.","metaTitle":"Siemens 3UG4512-2BR20 SIRIUS Phase Monitoring Relay, 160–690","metaDescription":"Siemens SIRIUS 3UG4512-2BR20 phase monitoring relay, 160–690 V AC, 50/60 Hz, 3 A rated, 22.5 mm wide, snap-on mounting, IP20. Current lifecycle stage. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"NRND","categoryPath":["Process / Temperature Controllers"],"specifications":{"Depth":"91 mm","Solid":"24 ... 16","Width":"22.5 mm","Height":"94 mm","Upwards":"0 mm","at 24 V":"1 A","Forwards":"0 mm","Stranded":"24 ... 16","at 125 V":"0.2 A","at 250 V":"0.1 A","Backwards":"0 mm","Downwards":"0 mm","auto-RESET":"Yes","At The Side":"0 mm","Initial Value":"1","During Storage":"-40 ... +85 °C","For Monitoring":"AC","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","During Transport":"-40 ... +85 °C","Fastening Method":"snap-on mounting","Full-Scale Value":"1","Product Function":"Phase monitoring relay","Delayed Switching":"2","Mounting Position":"any","Product Brand Name":"SIRIUS","Asymmetry Detection":"No","Between The Outputs":"Yes","Degree Of Pollution":"3","at AWG cables solid":"2x (24 ... 16)","display version LED":"Yes","protection class IP":"IP20","at 250 V at 50/60 Hz":"3 A","at 400 V at 50/60 Hz":"3 A","at 50 Hz rated value":"160 ... 690 V","at 60 Hz rated value":"160 ... 690 V","Design Of The Product":"2 functions","Overvoltage Detection":"No","For Auxiliary Contacts":"2","Undervoltage Detection":"No","at AWG cables stranded":"2x (24 ... 16)","Phase Failure Detection":"Yes","Between Input And Output":"Yes","Relative Repeat Accuracy":"1 %","measurable voltage at AC":"160 ... 690 V","Phase Sequence Recognition":"Yes","Of The Control Supply Voltage":"AC","Overvoltage Detection 3 Phase":"No","Substance Prohibitance (Date)":"05/28/2009","Type Of Electrical Connection":"spring-loaded terminals","Undervoltage Detection 3 Phases":"No","Voltage Window Recognition 3 Phase":"No","operational current at 17 V minimum":"5 mA","Surge Voltage Resistance Rated Value":"6 kV","With Degree Of Pollution 3 Rated Value":"690 V","due to burst according to IEC 61000-4-4":"2 kV","number of NC contacts delayed switching":"0","number of NO contacts delayed switching":"0","reference code according to IEC 81346-2":"K","Finely Stranded With Core End Processing":"0.25 ... 1.5 mm²","Number Of Poles For Main Current Circuit":"3","Finely Stranded Without Core End Processing":"0.25 ... 1.5 mm²","shock resistance according to IEC 60068-2-27":"sinusoidal half-wave 15g / 11 ms","Between The Voltage Supply And Other Circuits":"Yes","operating frequency with 3RT2 contactor maximum":"5 000 1/h","vibration resistance according to IEC 60068-2-6":"1 ... 6 Hz: 15 mm, 6 ... 500 Hz: 2g","Adjustable Open/Closed-Circuit Current Principle":"No","Mechanical Service Life (Operating Cycles) Typical":"10 000 000","electrostatic discharge according to IEC 61000-4-2":"6 kV contact discharge / 8 kV air discharge","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Thermal Current Of The Switching Element With Contacts Maximum":"5 A","continuous current of the DIAZED fuse link of the output relay":"4 A","Product Component Removable Terminal For Auxiliary And Control Circuit":"Yes"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":null,"alternativesUrl":"https://aoctrl.com/api/mcp/products/3UG4512-2BR20/alternatives.json"},"ai":{"faq":[{"question":"What voltage range does the 3UG4512-2BR20 monitor?","answer":"It monitors three-phase AC lines from 160 to 690 V at 50 or 60 Hz. That covers 208 V through 600 V class supplies without a hardware change."},{"question":"What is the contact rating of the 3UG4512-2BR20?","answer":"The two changeover contacts are rated 3 A at 250 V AC and 3 A at 400 V AC, 50/60 Hz. At 24 V DC the rating is 1 A; at 125 V DC it drops to 0.2 A; at 250 V DC it is 0.1 A."},{"question":"How wide is the 3UG4512-2BR20 and how does it mount?","answer":"It is 22.5 mm wide — one standard DIN-rail module. It snaps onto a 35 mm rail; no tools required. Mounting position is any orientation."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3UG4512-2BR20","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/3UG4512-2BR20 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}}