{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2150-4KA38-0AP0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2150-4KA38-0AP0","canonicalUrl":"https://aoctrl.com/siemens/3RA2150-4KA38-0AP0","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2150-4KA38-0AP0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2150-4KA38-0AP0 direct on-line starter, S2 size, 73 A AC-3 at 400 V, Class 10 thermal bimetallic overload, screw terminals, 55 x 150 x 274 mm.","salesMarkdown":"## Panel fit for an S2 direct starter The 3RA2150-4KA38-0AP0 is a direct on-line starter — across-the-line motor starting with no soft-start or VFD. It ships as a pre-assembled unit: the 3RT2038-1AP00 contactor, the thermal bimetallic overload relay, and the 3RA2931-1AA00 link module that wires the two together. Mounting uses screw fixing or snap-on to two parallel 35 mm DIN rails — the S2 frame needs the dual-rail stability because the assembly is 274 mm tall and 150 mm deep. Plan for 55 mm of DIN-rail width per starter; the depth clearance behind the panel door must accommodate the 150 mm projection plus wiring space. Ambient temperature compensation is active across the -20 to +60 °C operating range, but the bimetallic element still tracks enclosure temperature, so avoid mounting directly above heat sources. ## AC-3 and AC-3e duty — what 73 A means for motor sizing Rated 73 A at AC-3 400 V and 73 A at AC-3e 400 V — the AC-3 figure covers standard squirrel-cage motor starting (6–8× inrush, switching off at running current), while the AC-3e rating adds margin for higher switching frequencies typical in cyclic applications. Both ratings are identical here, so the contactor is not derated for the enhanced duty class. At 480 V the rating drops to 65 A, and at 600 V to 62 A — the current ceiling follows the voltage rise because the contactor's arc extinction capability is voltage-limited. For a 37 kW motor at 400 V (the listed power rating), the 73 A AC-3 figure gives headroom above the motor FLA of roughly 65–68 A for a standard efficiency motor. The maximum rated operational voltage is 690 V AC-3, so this starter can be used on 400/480/600 V systems without exceeding the contactor's voltage withstand. The screw-type main circuit terminals accept standard lug sizes for the S2 frame current range. ## Lifecycle and sourcing — active line, no obsolescence watch The substance prohibitance date of 03/01/2017 confirms RoHS compliance per EU Directive 2011/65/EU. No stock-holding claim; each RFQ is priced against the day's market.","metaTitle":"Siemens 3RA2150-4KA38-0AP0 SIRIUS Direct Starter, 73 A AC-3","metaDescription":"Siemens 3RA2150-4KA38-0AP0 SIRIUS direct on-line starter, 73 A at AC-3 400 V, S2 frame, Class 10 thermal overload.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"150 mm","Width":"55 mm","title":"3RA2150-4KA38-0AP0","Height":"274 mm","Upwards":"50 mm","Forwards":"32 mm","at 50 Hz":"0.37","Backwards":"0 mm","Downwards":"10 mm","Trip Class":"CLASS 10","At The Side":"10 mm","Rated Value":"690 V","description":"Load feeder fuseless, Direct-on-line starting 400 V AC, Size S2 62... 65 A 230 V AC, 50 Hz screw terminal for installation on standard mounting rail (also fulfills type of coordination 1) Type of coordination 2, Iq = 150 kA 1 NO+1 NC (contactor)","During Storage":"-50 ... +80 °C","lifecycle_stage":"current","During Operation":"-20 ... +60 °C","During Transport":"-50 ... +80 °C","Fastening Method":"screw and snap-on mounting to two 35 mm DIN rails","Mounting Position":"vertical, horizontal","PROFIsafe protocol":"No","Product Brand Name":"SIRIUS","Type Of Assignment":"2","Product Designation":"Direct (on-line) starter","Size Of Load Feeder":"S2","PROFINET IO protocol":"No","at 400 V rated value":"37 000 kW","at 480 V rated value":"65 A","at 50 Hz rated value":"230 ... 230 V","at 600 V rated value":"62 A","Design Of The Product":"for standard rail or screw mounting","For Main Current Circuit":"screw-type terminals","Temperature Compensation":"-20 ... +60 °C","Of The Supplied Contactor":"3RT2038-1AP00","Of The Supplied Link Module":"3RA2931-1AA00","Size Of The Circuit-Breaker":"S2","at AC-3 rated value maximum":"690 V","at AC-3 at 400 V rated value":"73 A","Substance Prohibitance (Date)":"03/01/2017","at AC-3e at 400 V rated value":"73 A","Design Of The Overload Release":"thermal (bimetallic)","Design Of The Switching Contact":"electromechanical","Operating Frequency Rated Value":"50 ... 60 Hz","Design Of The Short-Circuit Trip":"magnetic","Of The Supplied Circuit-Breakers":"3RV2032-4KA10","degree of protection NEMA rating":"other","For Auxiliary And Control Circuit":"screw-type terminals","Product Extension Auxiliary Switch":"Yes","Relative Humidity During Operation":"10 ... 95 %","Without Load Current Share Typical":"16 W","Surge Voltage Resistance Rated Value":"6 kV","at AC in hot operating state per pole":"15.5 W","Number Of Poles For Main Current Circuit":"3","Product Function Short Circuit Protection":"Yes","apparent holding power of magnet coil at AC":"16 VA","protocol is supported AS-Interface protocol":"No","reference code according to IEC 81346-2:2019":"Q","shock resistance according to IEC 60068-2-27":"6g / 11 ms","Type Of Voltage Of The Control Supply Voltage":"AC","at 400 V according to IEC 60947-4-1 rated value":"150 000 A","Inductive Power Factor With The Holding Power Of The Coil":"0.37","Mechanical Service Life (Operating Cycles) Of Contactor Typical":"10 000 000","Response Value Current Of Instantaneous Short-Circuit Trip Unit":"949 A","insulation voltage with degree of pollution 3 at AC rated value":"690 V","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"62 ... 65 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/1cb9c625d83effaf4e25fb7e0bacad0e.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=379597&mlfb=3RA2150-4KA38-0AP0"},"ai":{"faq":[{"question":"What is the AC-3 current rating at 400 V for 3RA2150-4KA38-0AP0?","answer":"73 A at AC-3 400 V and 73 A at AC-3e 400 V — the AC-3e rating confirms the contactor handles higher switching frequencies without derating."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2150-4KA38-0AP0","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/3RA2150-4KA38-0AP0 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}}