{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH1951-1SA11","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH1951-1SA11","canonicalUrl":"https://aoctrl.com/siemens/3RH1951-1SA11","factsUrl":"https://aoctrl.com/api/mcp/products/3RH1951-1SA11","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH1951-1SA11 auxiliary contact block, 1 NO + 1 NC, side-mount for 3RT135/136/137 contactors, screw terminals, 10 mm width, IP20.","salesMarkdown":"## Side-mount auxiliary block for 3RT135/136/137 The 3RH1951-1SA11 is a SIRIUS auxiliary contact block designed to mount laterally on Siemens 3RT135, 3RT136, and 3RT137 contactors — it does not mount on the front or replace the standard contactor auxiliary stack. It provides one normally-open (NO) and one normally-closed (NC) instantaneous contact, with no leading or lagging switching contacts. ## Rated current across the voltage range At AC-15 duty (solenoid/contactor control) the rated current at 690 V is 2 A — this is the switching capacity for inductive loads at the upper end of the voltage range. The contacts are mirror-contact compliant per IEC 60947-4-1 when used with the 3RT135/136/137 contactors, meaning the NC position mechanically mirrors the NO position — critical for safety circuits where welded NO contacts must not mask an open NC. ## Panel fit and wiring constraints At 10 mm wide, 79 mm high, and 67 mm deep, this block adds minimal DIN-rail footprint — it snaps onto the contactor side without occupying additional rail space. Front protection is IP20 — finger-safe for the operator side, but the contactor assembly itself must be inside an enclosure for washdown or dusty environments. RoHS compliance date listed as March 27, 2017 — the part meets the EU substance restrictions in effect from that date.","metaTitle":"Siemens 3RH1951-1SA11 SIRIUS Auxiliary Switch, 1 NO + 1 NC","metaDescription":"Siemens 3RH1951-1SA11 SIRIUS auxiliary contact block, 1 NO + 1 NC, side-mount for 3RT135/136/137 contactors.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"67 mm","Solid":"1x (1 ... 4mm²), 2x (1 ... 4mm²)","Width":"10 mm","title":"3RH1951-1SA11","Height":"79 mm","at 24 V":"3 A","at 48 V":"1.5 A","at 60 V":"1 A","at 110 V":"0.55 A","at 125 V":"0.55 A","at 220 V":"0.3 A","at 230 V":"4 A","at 250 V":"0.3 A","at 400 V":"3 A","description":"Additional auxiliary contact block for 3RT135, 3RT136, 3RT137 1 NC 1 NO, can be mounted on the side, screw terminal","During Storage":"-40 ... +70 °C","Leading Contact":"0","lifecycle_stage":"current","During Operation":"-40 ... +60 °C","Fastening Method":"snap-on mounting","Lagging Switching":"0","Solid Or Stranded":"1x (1 ... 4mm²), 2x (1 ... 4mm²)","Product Brand Name":"SIRIUS","Product Designation":"auxiliary switch","Suitability For Use":"for 3RT135, 3RT136, 3RT137","Design Of The Product":"second can be mounted laterally","Instantaneous Contact":"1","Substance Prohibitance (Date)":"03/27/2017","protection class IP on the front":"IP20","Surge Voltage Resistance Rated Value":"6 kV","for AWG cables for auxiliary contacts":"1x (AWG 18 ... 14), 2x (AWG 18 ... 14)","Finely Stranded With Core End Processing":"1x (0.75 ... 2.5 mm²), 2x (0.75 ... 2.5 mm²)","mirror contact according to IEC 60947-4-1":"Yes; with 3RT135, 3RT136, 3RT137","operational current at AC-15 at 690 V rated value":"2 A","Type Of Electrical Connection For Auxiliary And Control Circuit":"screw-type terminals","insulation voltage with degree of pollution 3 at AC rated value":"690 V","number of CO contacts of auxiliary contacts instantaneous contact":"0","AWG number as coded connectable conductor cross section for auxiliary contacts":"18 ... 14"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/56f7bb2103fddf898f0d9a908ce07d29.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1043701&mlfb=3RH1951-1SA11"},"ai":{"faq":[{"question":"What contactors does the 3RH1951-1SA11 mount on?","answer":"It mounts laterally on Siemens 3RT135, 3RT136, and 3RT137 contactors. It does not fit the front auxiliary slot — it is a side-mount block only."},{"question":"What is the AC-15 rated current at 690 V?","answer":"The AC-15 rated operational current at 690 V is 2 A. This is the switching capacity for inductive loads like contactor coils at that voltage."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH1951-1SA11","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/3RH1951-1SA11 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}