{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5SU1644-2RC32","brand":"Siemens","brandSlug":"siemens","productSlug":"5SU1644-2RC32","canonicalUrl":"https://aoctrl.com/siemens/5SU1644-2RC32","factsUrl":"https://aoctrl.com/api/mcp/products/5SU1644-2RC32","rawCanonicalId":null},"summary":{"shortDescription":"Siemens 5SU1644-2RC32 RCBO, 32 A, 4-pole, 8 modules, D characteristic, Type AC, 300 mA residual current.","salesMarkdown":"It occupies 8 module widths on a DIN rail, which is the standard 144 mm — a factor to check against enclosure fill limits when retrofitting into an existing panel. The 32 A rating governs the thermal overload element; continuous load should not exceed 32 A, and the D curve's magnetic threshold (320–640 A instantaneous) clears hard faults without coordination issues downstream. Type AC residual current detection handles sinusoidal AC earth faults only. For variable-speed drives, UPS outputs, or LED lighting with rectifiers, a Type A or Type F RCD would be required — Type AC will not reliably detect the fault waveforms those loads generate. The 300 mA residual sensitivity is a fire-protection level, not personnel protection (30 mA is the threshold for direct contact). This unit is intended for sub-distribution or feeder circuits where the earth leakage is expected to be higher than 30 mA but still needs ground-fault detection to prevent cable overheating and fire risk. Snap-on DIN rail mounting per EN 60715. At 8 modules (144 mm), it occupies a full row on a standard 12-module distribution board. Verify the busbar comb arrangement — 4-pole RCBOs require a 4-conductor busbar with the neutral pole switched. The neutral pole is on the right-hand side (phase sequence L1-L2-L3-N). This RCBO combines overcurrent protection (MCB function) and residual current protection (RCD function) in a single 4-pole device, saving one module width compared to separate MCB + RCD units. The 32 A D curve with 300 mA Type AC residual covers the common specification for motor feeder circuits in commercial and light industrial sub-distribution boards where earth leakage is monitored for fire prevention rather than personnel shock protection.","metaTitle":"Siemens 5SU1644-2RC32 RCBO 32 A 4-pole D curve 300 mA","metaDescription":"Siemens 5SU1644-2RC32 RCBO, 32 A, 4-pole, 8 modules, D characteristic, Type AC, 300 mA residual current. Current lifecycle stage. Sourced to order against an 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":"https://cdn.aoctrl.com/bed74928c9539d6c50f1eb1e06da07d1.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=309467&mlfb=5SU1644-2RC32","alternativesUrl":"https://aoctrl.com/api/mcp/products/5SU1644-2RC32/alternatives.json"},"ai":{"faq":[{"question":"What is the 5SU1644-2RC32 used for?","answer":"It is a 4-pole RCBO rated 32 A with a D tripping characteristic and 300 mA Type AC residual current detection, used for combined overcurrent and earth-fault protection in motor circuits, transformers, and other high-inrush loads in sub-distribution boards."},{"question":"Where can I buy the 5SU1644-2RC32?","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 does D characteristic mean on this RCBO?","answer":"The D characteristic means the magnetic trip operates at 10–20 times the rated current (320–640 A instantaneous for this 32 A unit), designed to avoid nuisance tripping from high inrush currents typical of motors and transformers."},{"question":"What is the difference between Type AC and Type A RCD?","answer":"Type AC detects sinusoidal AC residual currents only. Type A additionally detects pulsating DC residual currents. For circuits with VFDs, UPS, or LED drivers, Type A or Type F is required; Type AC is suitable for general resistive and inductive loads without rectified waveforms."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5SU1644-2RC32","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/5SU1644-2RC32 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}}