{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SM3621-4","brand":"Siemens","brandSlug":"siemens","productSlug":"5SM3621-4","canonicalUrl":"https://aoctrl.com/siemens/5SM3621-4","factsUrl":"https://aoctrl.com/api/mcp/products/5SM3621-4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 5SM3621-4, 2-pole Type B RCCB, short-time delayed, In 16 A, IΔn 300 mA, Un 230 V AC, 10 kA SCCR, DIN rail mount, IP20.","salesMarkdown":"The Siemens 5SM3621-4 is a 2-pole SENTRON residual current operated circuit breaker (RCCB) rated for 16 A at 230 V AC, with a 300 mA Type B trip characteristic and short-time delayed switching. Type B detection covers smooth DC fault currents up to the rated residual, plus AC and pulsed DC — so it handles variable-speed drives, UPS systems, and PV inverters where pure AC-sensing RCCBs would miss a DC fault. The 300 mA trip threshold is sized for equipment protection and fire prevention, not personnel shock — 30 mA units cover that. The short-time delay (S) characteristic prevents nuisance tripping when downstream equipment generates brief inrush or leakage spikes, like motor starting or capacitor banks. At 16 A continuous, it's sized for lighting subcircuits, small motor groups, or general socket outlets on a 230 V single-phase supply. The 2-pole (1-phase + neutral) form factor occupies 4 width units (72 mm) on DIN rail, so it needs that space in the distribution board. ## Integration notes Mounts on DIN rail (REG) in any position. Terminals accept solid or stranded conductors from 1.5 to 25 mm²; tighten to 2.5–3 N·m. Ambient range is -25 to +45 °C operating, -40 to +75 °C storage. IP20 with connected conductors in an installed distribution board — so it's panel-internal, not washdown-rated. The top or bottom supply position works for most layouts, and the SIGRES function remains active in the off state when fed from the bottom.","metaTitle":"Siemens 5SM3621-4 SENTRON RCCB, 2-pole Type B, 16 A, 300 mA","metaDescription":"Siemens 5SM3621-4 SENTRON RCCB, 2-pole, Type B, short-time delayed, 16 A rated, 300 mA trip, 230 V AC, 10 kA SCCR, DIN rail. Current lifecycle stage. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Residual Current Breakers (RCCB/RCBO)"],"specifications":{"Depth":"70 mm","Solid":"1.5 ... 25 mm²","Width":"72 mm","Height":"90 mm","Stranded":"1.5 ... 25 mm²","Rated Value":"50 Hz","Mounting type":"DIN rail (REG)","During Storage":"-40 ... +75 °C","Number of poles":"2","lifecycle_stage":"current","Mounting position":"any","Installation depth":"70 mm","Product brand name":"SENTRON","Ambient temperature":"-25 ... +45 °C","Operating frequency":"50/60Hz","Product designation":"RCCB","Protection class IP":"IP20, if the distribution board is installed, with connected conductors","Overvoltage category":"III","Design of the product":"Short-time delayed","Number of width units":"4","Type of fault current":"B","acc. to DIN EN 61346-2":"F","acc. to DIN EN 81346-2":"F","circuit-breaker / Design":"5SM3","Short-circuit current rating":"10 kA","Current / at AC / rated value":"16 A","Product feature / silicon-free":"Yes","Position / of power supply cord":"Top or bottom (bottom for SIGRES function also in switched-off state)","Protection against electrical shock":"Finger and back-of-hand safe","Supply voltage / at AC / rated value":"230 V","Surge current resistance / rated value":"3 kA","Switching function / short-term delayed":"Yes","Tripping residual current / rated value":"300 mA","Tightening torque / with screw-type terminals":"2.5 ... 3 N·m","Size of installation devices / acc. to DIN 43880":"1","Supply voltage / for testing equipment / minimum":"195 V","Mechanical service life (switching cycles) / typical":"10 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=342929&mlfb=5SM3621-4","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SM3621-4/alternatives.json"},"ai":{"faq":[{"question":"What is the 5SM3621-4 used for?","answer":"It's a Type B RCCB for equipment and fire protection on 230 V AC single-phase circuits, detecting smooth DC, AC, and pulsed DC fault currents. The short-time delay prevents nuisance tripping on loads with brief inrush or leakage."},{"question":"Where can I buy the 5SM3621-4 and how is it quoted?","answer":"Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — no stock count or price is published here."},{"question":"What is the depth of the 5SM3621-4?","answer":"70 mm installation depth, which fits standard 80 mm deep distribution enclosures."},{"question":"What conductor sizes does the 5SM3621-4 accept?","answer":"Solid or stranded conductors from 1.5 to 25 mm², with a tightening torque of 2.5 to 3 N·m."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SM3621-4","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/5SM3621-4 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}}