{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SU1656-0KV40","brand":"Siemens","brandSlug":"siemens","productSlug":"5SU1656-0KV40","canonicalUrl":"https://aoctrl.com/siemens/5SU1656-0KV40","factsUrl":"https://aoctrl.com/api/mcp/products/5SU1656-0KV40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens 5SU1656-0KV40 FI/LS protector, Type AC (WS), D=70mm, IΔn 300mA, 6kA, 1+N-pole, B-curve 40A.","salesMarkdown":"The Siemens 5SU1656-0KV40 is a combined residual current device and miniature circuit breaker (RCBO) in a single 1+N-pole module. It integrates a Type AC RCD rated at 300 mA residual sensitivity with a B-curve MCB rated at 40 A, all in a 70 mm deep enclosure. The 300 mA IΔn is a fire-protection level, not a person-protection level — 30 mA is the touch-safe threshold per IEC 60364. This unit goes into circuits where nuisance tripping from normal leakage (long cable runs, IT equipment) would be unacceptable, but where earth-fault fire risk still needs covering. The 6 kA Icn at 230/400 V is the short-circuit capacity the device can safely interrupt — adequate for TN and TT systems with upstream overcurrent protection sized to keep let-through energy within the device's limits. ## Integration note The 70 mm depth is a key fit dimension for shallow enclosures — many standard RCBOs run 75–80 mm deep, so this unit buys an extra 5–10 mm of wiring space behind the DIN rail. The 1+N-pole format (switched phase, solid neutral) is the common European residential/commercial configuration. Terminal capacity and wire range are standard for the class; verify against your gland-plate and busbar layout before committing the panel layout.","metaTitle":"Siemens 5SU1656-0KV40 FI/LS Protector, Type AC, 40A B, 300mA","metaDescription":"Siemens 5SU1656-0KV40 FI/LS protector, Type AC, 40A B-curve, 300mA, 6kA, 1+N-pole. 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":{"lifecycle_stage":"current"}},"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=404368&mlfb=5SU1656-0KV40","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SU1656-0KV40/alternatives.json"},"ai":{"faq":[{"question":"What is the 5SU1656-0KV40 used for?","answer":"It is a combined RCD/MCB (RCBO) for final subcircuit protection. The 300 mA Type AC RCD provides fire protection against sinusoidal earth faults, while the 40 A B-curve MCB protects against overload and short circuit up to 6 kA."},{"question":"Where can I buy the 5SU1656-0KV40?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time."},{"question":"What is the difference between 30 mA and 300 mA RCD sensitivity?","answer":"30 mA is the person-protection threshold per IEC 60364 (touch-safe). 300 mA is a fire-protection level — it allows higher normal leakage current without nuisance tripping but does not protect against direct contact. The 5SU1656-0KV40 uses 300 mA for circuits where nuisance tripping from leakage is a concern."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SU1656-0KV40","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/5SU1656-0KV40 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}}