{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1276-6AT36","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1276-6AT36","canonicalUrl":"https://aoctrl.com/siemens/3RT1276-6AT36","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1276-6AT36","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS vacuum contactor, size S12, order code 3RT1276-6AT36, rated 575-600 V, screw fixing, 225 mm depth.","salesMarkdown":"Vacuum contactors are preferred for medium-voltage applications where arc quenching in air is less reliable — the vacuum bottle extinguishes the arc cleanly, reducing contact wear and extending service life. This unit is rated for 575 to 600 V AC, so it fits 575 V or 600 V nominal systems common in North American heavy industrial plants. Mechanical life is rated at 10,000,000 operations typical, and the contactor can handle up to 750 switching operations per hour under AC-3 duty (motor starting). That puts it in the heavy-duty cycling class — suitable for frequent-start applications like conveyors, pumps, and compressors that cycle multiple times per shift. ## Mounting and wiring reality Mounting is screw fixing — no DIN rail snap-on here. The contactor measures 214 mm high, 160 mm wide, and 225 mm deep. That depth (225 mm) is the dimension that matters most when laying out the gland plate and door clearance: you need at least that much space behind the panel door plus room for the incoming cable bend radius. Power wiring accepts stranded cable from 70 mm² up to 240 mm² — that's substantial copper, sized for the full rated current at 575-600 V. Auxiliary control wiring uses screw-type terminals on the magnet coil, accepting 2x (0.5 to 1.5 mm²) solid or 2x (0.75 to 2.5 mm²) stranded, max 2x (0.75 to 4 mm²). The auxiliary switch is present (yes), so you get a feedback contact for the PLC or safety circuit without adding an external block. The 575-600 V AC rating tells you this is a 600 V class device, not a 480 V one — it's built for the higher nominal voltage common in Canadian and US heavy industrial plants (575 V) or 600 V systems. At 24 V DC the auxiliary contact is rated 10 A; at 48 V and 60 V it drops to 2 A. That derating curve matters when you're driving a PLC output or a small control relay — don't assume the 10 A holds at higher control voltages. The storage range is wider because it's a handling limit, not a running one. If this contactor sits in an unheated warehouse in a Canadian winter, -55 °C storage is fine — but it won't start pulling in until it warms above -25 °C.","metaTitle":"Siemens 3RT1276-6AT36 SIRIUS Vacuum Contactor, S12, 575-600V","metaDescription":"Siemens 3RT1276-6AT36 SIRIUS vacuum contactor, size S12, rated 575-600 V AC. Screw fixing, 225 mm depth. Current lifecycle. Quoted to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"225 mm","Solid":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), max. 2x (0.75 ... 4 mm²)","Width":"160 mm","at AC":"60 ... 100 ms","at DC":"60 ... 100 ms","title":"3RT1276-6AT36","Height":"214 mm","Upwards":"10 mm","Forwards":"20 mm","Stranded":"70 ... 240 mm²","at 50 Hz":"0.9","at 60 Hz":"0.9","Downwards":"10 mm","Arcing Time":"10 ... 15 ms","At The Side":"10 mm","Rated Value":"575 ... 600 V","description":"vacuum contactor AC-3e/AC-3 500 A, 250 kW / 400 V, 3-pole, Uc: 575-600 V AC(50-60 Hz) / DC drive: conventional auxiliary contacts 2 NO + 2 NC main circuit: busbar control and auxiliary circuit: screw terminal","Initial Value":"0.8","During Storage":"-55 ... +80 °C","Of Magnet Coil":"Screw-type terminals","Number Of Holes":"1","at AC-1 maximum":"700 1/h","at AC-2 maximum":"250 1/h","at AC-3 maximum":"750 1/h","at AC-4 maximum":"250 1/h","lifecycle_stage":"current","Auxiliary Switch":"Yes","During Operation":"-25 ... +60 °C","Fastening Method":"screw fixing","Full-Scale Value":"1.1","at AC-3e maximum":"750 1/h","Diameter Of Holes":"11 mm","Mounting Position":"+/-22,5° rotation possible on vertical mounting surface; can be tilted forward and backward by +/- 22.5° on vertical mounting surface; standing, on horizontal mounting surface","Size Of Contactor":"S12","Solid Or Stranded":"2x (0,5 ... 1,5 mm²), 2x (0,75 ... 2,5 mm²), max. 2x (0,75 ... 4 mm²)","Product Brand Name":"SIRIUS","Product Designation":"Vacuum contactor","at 24 V rated value":"10 A","at 48 V rated value":"2 A","at 60 V rated value":"2 A","Of Contactor Typical":"10 000 000","at 110 V rated value":"1 A","at 125 V rated value":"0.9 A","at 220 V rated value":"0.3 A","at 230 V rated value":"6 A","at 400 V rated value":"3 A","at 480 V rated value":"477 A","at 50 Hz rated value":"575 ... 600 V","at 500 V rated value":"2 A","at 60 Hz rated value":"575 ... 600 V","at 600 V rated value":"472 A","at 690 V rated value":"1 A","Side-By-Side Mounting":"Yes","at 1000 V rated value":"710 kW","For Auxiliary Contacts":"18 ... 14","Width Of Connection Bar":"25 mm","For Main Current Circuit":"Connection bar","at 200/208 V rated value":"150 hp","at 220/230 V rated value":"200 hp","at 460/480 V rated value":"400 hp","at 575/600 V rated value":"500 hp","Relative Humidity Minimum":"10 %","Of Main Circuit Rated Value":"8 kV","Thickness Of Connection Bar":"6 mm","at AC-3 rated value maximum":"1 000 V","at AC in hot operating state":"96 W","at AC-3e rated value maximum":"1 000 V","at AC-4 at 400 V rated value":"430 A","safety-related switching OFF":"Yes","Substance Prohibitance (Date)":"05/01/2012","Design Of The Surge Suppressor":"with varistor","Of Auxiliary Circuit Rated Value":"6 kV","For Auxiliary And Control Circuit":"screw-type terminals","Function Module For Communication":"No","With Type Of Assignment 2 Required":"gG: 800 A (690 V, 50 kA), aM: 630 A (690 V, 50 kA), BS88: 800 A (415 V, 50 kA)","Without Load Current Share Typical":"10 W","closing power of magnet coil at DC":"920 W","holding power of magnet coil at DC":"10 W","At Contactor For Auxiliary Contacts":"Screw-type terminals","With Type Of Coordination 1 Required":"gG: 800 A (690 V, 100 kA)","operational current at AC-12 maximum":"10 A","at AC in hot operating state per pole":"32 W","for AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14), 1x 12","number of NO contacts for main contacts":"3","reference code according to IEC 81346-2":"Q","Finely Stranded With Core End Processing":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","Number Of Poles For Main Current Circuit":"3","Contact Reliability Of Auxiliary Contacts":"1 faulty switching per 100 million (17 V, 1 mA)","mirror contact according to IEC 60947-4-1":"Yes","Type Of Voltage Of The Control Supply Voltage":"AC/DC","contact rating of auxiliary contacts according to UL":"A600 / Q600","Of Main Circuit With Degree Of Pollution 3 Rated Value":"1 000 V","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Of The Contactor With Added Auxiliary Switch Block Typical":"10 000 000","Of Auxiliary Circuit With Degree Of Pollution 3 Rated Value":"500 V","For Short-Circuit Protection Of The Auxiliary Switch Required":"gG: 10 A (500 V, 1 kA)","minimum cross-section in main circuit at maximum AC-1 rated value":"370 mm²","number of NC contacts for auxiliary contacts instantaneous contact":"2","number of NO contacts for auxiliary contacts instantaneous contact":"2","Of The Contactor With Added Electronically Optimized Auxiliary Switch Block Typical":"5 000 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/4f21e07eea04acb567a0400edd6ffb36.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=154835&mlfb=3RT1276-6AT36"},"ai":{"faq":[{"question":"What is the depth of 3RT1276-6AT36?","answer":"The depth is 225 mm, which is the critical dimension for panel depth clearance and cable bend radius behind the door."},{"question":"What wire sizes does 3RT1276-6AT36 accept on the power side?","answer":"The power terminals accept stranded cable from 70 mm² up to 240 mm². Auxiliary control wiring uses screw terminals accepting 2x (0.5 to 1.5 mm²) solid or 2x (0.75 to 2.5 mm²) stranded, max 2x (0.75 to 4 mm²)."},{"question":"Where can I buy 3RT1276-6AT36 and how is it quoted?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm price and lead time."},{"question":"Will 3RT1276-6AT36 drop into a panel specified for 3RT1264-6AP36-0KA1?","answer":"The 3RT1276-6AT36 is a size S12 vacuum contactor with screw fixing and a 225 mm depth. The 3RT1264-6AP36-0KA1 is a different variant — verify mounting hole pattern and depth clearance against your panel layout before assuming a drop-in swap, as the physical dimensions and fixing method may differ."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1276-6AT36","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/3RT1276-6AT36 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}}