{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1055-2NB36","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1055-2NB36","canonicalUrl":"https://aoctrl.com/siemens/3RT1055-2NB36","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1055-2NB36","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS, power contactor, size S6, 3RT1055-2NB36, rated control supply voltage 21-27.3 V DC, screw fixing, spring-type coil terminals, auxiliary switch included.","salesMarkdown":"Its rated control supply voltage of 21... 27.3 V DC means the coil holds in at 21 V and drops out below that — critical to verify your DC supply rail doesn't sag under load. The 10 A rated current at 24 V DC on the auxiliary contacts tells you the auxiliary circuit can handle a modest pilot-duty load, but the 1 A rating at 110 V DC is the real limit for DC inductive switching. Screw fixing and a vertical mounting surface with +/-90° rotation and +/-22.5° tilt gives panel builders flexibility in tight enclosures, but the 170 mm depth and 120 mm width demand a 200 mm deep cabinet minimum for cable bending radius. ## Switching rates and duty cycles The maximum operating rates tell you what this contactor can sustain thermally: 800 operations per hour in AC-1 resistive duty, 750 in AC-3 motor starting, but only 130 in AC-4 plugging/reversing. For a conveyor drive cycling every 30 seconds, AC-3 at 750 ops/h is comfortable; a press brake that reverses every 5 seconds exceeds the AC-4 limit and requires a larger frame or a dedicated reversing contactor pair. Arcing time of 10... 15 ms and operating times of 80... 90 ms (both AC and DC) are standard for this frame size. The 0.6 power factor at 50/60 Hz indicates the contactor is rated for motor loads with typical lagging PF — no derating needed for standard induction motors. Main power terminals accept 25... 120 mm² stranded copper — that's a 2/0 AWG equivalent, sized for a 100+ A motor circuit. The coil terminals are spring-type, accepting 2x (0.25... 2.5 mm²) solid or stranded, so you can daisy-chain the control wiring without ring terminals. Four 9 mm mounting holes on a screw-fixing pattern; spacing requires 10 mm clearance upwards, downwards, and to the side, plus 20 mm forwards for arc-chamber ventilation.","metaTitle":"Siemens 3RT1055-2NB36 SIRIUS Power Contactor, 21-27.3 VDC Co","metaDescription":"Siemens SIRIUS 3RT1055-2NB36 power contactor, size S6. 21-27.3 VDC coil, screw fixing, auxiliary switch. Sourced to order against RFQ. Depth 170 mm.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"170 mm","Solid":"2x (0.25 ... 2.5 mm²)","Width":"120 mm","at AC":"80 ... 90 ms","at DC":"80 ... 90 ms","title":"3RT1055-2NB36","Height":"172 mm","Upwards":"10 mm","Forwards":"20 mm","Stranded":"25 ... 120 mm²","at 50 Hz":"0.6","at 60 Hz":"0.6","Downwards":"10 mm","Arcing Time":"10 ... 15 ms","At The Side":"10 mm","Rated Value":"21 ... 27.3 V","description":"power contactor, AC-3e/AC-3 150 A, 75 kW / 400 V AC (50-60 Hz) / DC Uc: 21-27, 3 V PLC input 24 V DC 3-pole, auxiliary contacts 2 NO + 2 NC drive: electronic main circuit: busbar control and auxiliary circuit: spring-loaded terminal","Initial Value":"0.8","During Storage":"-55 ... +80 °C","Of Magnet Coil":"Spring-type terminals","Number Of Holes":"1","at AC-1 maximum":"800 1/h","at AC-2 maximum":"300 1/h","at AC-3 maximum":"750 1/h","at AC-4 maximum":"130 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":"9 mm","Mounting Position":"with vertical mounting surface +/-90° rotatable, with vertical mounting surface +/- 22.5° tiltable to the front and back","Size Of Contactor":"S6","Solid Or Stranded":"2x (0,25 ... 2,5 mm²)","Product Brand Name":"SIRIUS","Product Designation":"Power 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":"30 hp","at 400 V rated value":"3 A","at 440 V rated value":"1.4 A","at 480 V rated value":"156 A","at 50 Hz rated value":"21 ... 27.3 V","at 500 V rated value":"2 A","at 60 Hz rated value":"21 ... 27.3 V","at 600 V rated value":"144 A","at 690 V rated value":"1 A","Side-By-Side Mounting":"Yes","at 1000 V rated value":"90 kW","For Auxiliary Contacts":"24 ... 14","Width Of Connection Bar":"17 mm","For Main Current Circuit":"Connection bar","at 200/208 V rated value":"50 hp","at 220/230 V rated value":"60 hp","at 460/480 V rated value":"125 hp","at 575/600 V rated value":"150 hp","Relative Humidity Minimum":"10 %","Of Main Circuit Rated Value":"8 kV","Thickness Of Connection Bar":"3 mm","at AC-3 rated value maximum":"1 000 V","at AC in hot operating state":"27 W","at AC-3e rated value maximum":"1 000 V","at AC-4 at 400 V rated value":"132 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","at AC-5a up to 690 V rated value":"162 A","at AC-5b up to 400 V rated value":"124 A","For Auxiliary And Control Circuit":"spring-loaded terminals","Function Module For Communication":"No","With Type Of Assignment 2 Required":"gG: 315 A (690 V, 100 kA), aM: 200 A (690 V, 50 kA), BS88: 315 A (415 V, 50 kA)","Without Load Current Share Typical":"2.8 W","closing power of magnet coil at DC":"320 W","holding power of magnet coil at DC":"2.8 W","At Contactor For Auxiliary Contacts":"Spring-type terminals","With Type Of Coordination 1 Required":"gG: 355 A (690 V, 100 kA)","at AWG cables for auxiliary contacts":"2x (24 ... 14)","operational current at AC-12 maximum":"10 A","at AC in hot operating state per pole":"9 W","number of NO contacts for main contacts":"3","reference code according to IEC 81346-2":"Q","Finely Stranded With Core End Processing":"2x (0.25 ... 1.5 mm²)","Number Of Poles For Main Current Circuit":"3","voltage at PLC-control input rated value":"24 V","Contact Reliability Of Auxiliary Contacts":"1 faulty switching per 100 million (17 V, 1 mA)","mirror contact according to IEC 60947-4-1":"Yes","Finely Stranded Without Core End Processing":"2x (0.25 ... 2.5 mm²)","Type Of Voltage Of The Control Supply Voltage":"AC/DC","Limited To 1 S Switching At Zero Current Maximum":"2 727 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 5 S Switching At Zero Current Maximum":"1 831 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 10 S Switching At Zero Current Maximum":"1 300 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 30 S Switching At Zero Current Maximum":"850 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 60 S Switching At Zero Current Maximum":"703 A; Use minimum cross-section acc. to AC-1 rated value","type of PLC-control input according to IEC 60947-1":"Type 2","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","operating range factor of the voltage at PLC-control input":"0.8 ... 1.1","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":"95 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/48191814343ef1de12d436857500061f.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=319798&mlfb=3RT1055-2NB36"},"ai":{"faq":[{"question":"Where can I buy 3RT1055-2NB36 and get a price?","answer":"This part is sourced to order against an RFQ through independent distribution. Submit a quote request for current pricing and availability."},{"question":"What is the depth of 3RT1055-2NB36?","answer":"The depth is 170 mm, with an additional 20 mm forward clearance required for arc-chamber ventilation."},{"question":"What conductor sizes does 3RT1055-2NB36 accept?","answer":"Main power terminals accept 25 to 120 mm² stranded copper. Coil terminals accept 2x (0.25 to 2.5 mm²) solid or stranded via spring-type connections."},{"question":"Will 3RT1055-2NB36 drop into a panel built for 3RT1055-6QF35?","answer":"Both are size S6 SIRIUS contactors with the same mounting footprint and screw-fixing pattern, so physical fit is identical. The difference is the coil voltage — 3RT1055-2NB36 uses 21-27.3 V DC, while 3RT1055-6QF35 uses a different coil rating. Verify coil supply compatibility before swapping."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1055-2NB36","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/3RT1055-2NB36 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}}