{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2018-2XB42-2LA2","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2018-2XB42-2LA2","canonicalUrl":"https://aoctrl.com/siemens/3RT2018-2XB42-2LA2","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2018-2XB42-2LA2","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT2018-2XB42-2LA2 contactor, size S00, DC operated coil 24-34 V, spring-type terminals, 45 x 70 x 73 mm, screw and DIN rail mount.","salesMarkdown":"## S00 frame, DC coil — what this contactor is for The 3RT2018-2XB42-2LA2: The DC coil is rated 24–34 VDC, so it runs cleanly on a standard 24 V control supply with tolerance for a sagging bus. Spring-type terminals on the coil and main contacts mean no screw torque to check — strip, insert, done. ## Panel fit and clearance The envelope is 45 mm wide, 70 mm tall, 73 mm deep — the S00 width is the tightest in the line, so you can pack more contactors per DIN-rail metre than an S0 or S2 frame. Clearance requirements: 10 mm above, below, and forward; 6 mm to the sides. That side gap is tight — if you're stacking contactors side-by-side without a spacer bar, the arc chambers need that 6 mm to vent hot gases without flashover between poles. ## DC coil behaviour and drive requirements The DC coil pulls a 2.3 A inrush peak when energised, then settles to a holding current determined by the 24–34 VDC range. That inrush matters — if a PLC relay card or small solid-state output drives this coil, the contact must handle the surge without welding or dropout. Dropout time is 25–45 ms at DC, which is fast enough that the contactor clears before a downstream short-circuit protection device sees the fault current. Arcing time across the main contacts runs 10–15 ms — the arc extinguishes within one cycle at 50 Hz, so the upstream breaker's short-time delay won't see it as a fault. The AC-4 maximum switching rate is 250 operations per hour — that's the plugging or inching ceiling; continuous AC-3 switching runs faster but isn't specified here. ## Temperature range and mechanical endurance That covers unheated enclosures in cold climates and panels near process heat without derating. Mechanical life is 30 million cycles typical — the contactor outlasts most machines it controls. Electrical life at full rated load is lower and depends on switching frequency and load type; for AC-3 motor starting at rated current, expect several hundred thousand operations before contact replacement.","metaTitle":"Siemens 3RT2018-2XB42-2LA2 SIRIUS Contactor, S00","metaDescription":"Siemens 3RT2018-2XB42-2LA2 SIRIUS contactor, size S00, DC coil 24-34 V, spring terminals, 45 mm wide. Active production — quoted to order against your BOM.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"73 mm","Solid":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), 2x 4 mm²","Width":"45 mm","at DC":"25 ... 45 ms","Height":"70 mm","Upwards":"10 mm","Forwards":"10 mm","Downwards":"10 mm","Arcing Time":"10 ... 15 ms","At The Side":"6 mm","Rated Value":"24 ... 34 V","Initial Value":"0.7","During Storage":"-55 ... +80 °C","Of Magnet Coil":"Spring-type terminals","Type Of Voltage":"DC","at AC-4 maximum":"250 1/h","lifecycle_stage":"current","Auxiliary Switch":"Yes","During Operation":"-40 ... +70 °C","Fastening Method":"screw and snap-on mounting onto 35 mm standard mounting rail according to DIN EN 50022","Full-Scale Value":"1.25","For Main Contacts":"20 ... 12","Mounting Position":"hanging, on horizontal mounting surface","Size Of Contactor":"S00","Solid Or Stranded":"2x (0,5 ... 4 mm²)","Product Brand Name":"SIRIUS","Inrush Current Peak":"2.3 A","Product Designation":"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":"30 000 000","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":"2 hp","at 400 V rated value":"3 A","at 480 V rated value":"14 A","at 500 V rated value":"2 A","at 600 V rated value":"11 A","at 690 V rated value":"1 A","Design Of The Product":"With extended operating range","Instantaneous Contact":"1","Side-By-Side Mounting":"Yes","For Auxiliary Contacts":"20 ... 12","For Main Current Circuit":"spring-loaded terminals","at 110/120 V rated value":"1 hp","at 200/208 V rated value":"3 hp","at 220/230 V rated value":"5 hp","at 460/480 V rated value":"10 hp","at 575/600 V rated value":"10 hp","at AC-2 at AC-3e maximum":"750 1/h","Locked-Rotor Current Peak":"0.18 A","Relative Humidity Minimum":"10 %","Holding Current Mean Value":"40 mA","at maximum Ith rated value":"4 mm²","Of Main Circuit Rated Value":"6 kV","at AC-3 rated value maximum":"690 V","at maximum AC-1 rated value":"4 mm²","at AC in hot operating state":"6.6 W","at AC-2 at 400 V rated value":"7.5 kW","at AC-3e rated value maximum":"690 V","at AC-4 at 400 V rated value":"11.5 A","Substance Prohibitance (Date)":"10/01/2009","Design Of The Surge Suppressor":"with varistor","Duration Of Inrush Current Peak":"50 µs","Locked-Rotor Current Mean Value":"0.18 A","at AWG cables for main contacts":"2x (20 ... 12)","Duration Of Locked-Rotor Current":"250 ms","Of Auxiliary Circuit Rated Value":"6 kV","For Auxiliary And Control Circuit":"spring-loaded terminals","Function Module For Communication":"No","Product Function Bus Communication":"No","With Type Of Assignment 2 Required":"gG NH 3NA, DIAZED 5SB, NEOZED 5SE: 20 A","Without Load Current Share Typical":"0.7 W","closing power of magnet coil at DC":"4 W","holding power of magnet coil at DC":"0.95 W","At Contactor For Auxiliary Contacts":"Spring-type terminals","With Type Of Coordination 1 Required":"gG NH 3NA, DIAZED 5SB, NEOZED 5SE: 35 A","at AWG cables for auxiliary contacts":"2x (20 ... 12)","operational current at AC-12 maximum":"10 A","at AC in hot operating state per pole":"2.2 W","number of NC contacts for main contacts":"0","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 ... 2.5 mm²)","Number Of Poles For Main Current Circuit":"3","Product Function Short Circuit Protection":"No","mirror contact according to IEC 60947-4-1":"Yes","with low demand rate according to SN 31920":"40 %","Finely Stranded Without Core End Processing":"2x (0.5 ... 2.5 mm²)","with high demand rate according to SN 31920":"73 %","number of NC contacts for auxiliary contacts":"1","Type Of Voltage Of The Control Supply Voltage":"DC","up to 40 °C according to IEC 60077 rated value":"22 A","up to 70 °C according to IEC 60077 rated value":"18 A","Limited To 1 S Switching At Zero Current Maximum":"300 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 5 S Switching At Zero Current Maximum":"169 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 10 S Switching At Zero Current Maximum":"128 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 30 S Switching At Zero Current Maximum":"92 A; Use minimum cross-section acc. to AC-1 rated value","Limited To 60 S Switching At Zero Current Maximum":"74 A; Use minimum cross-section acc. to AC-1 rated value","contact rating of auxiliary contacts according to UL":"A600 / Q600","Of Main Circuit With Degree Of Pollution 3 Rated Value":"690 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":"690 V","For Short-Circuit Protection Of The Auxiliary Switch Required":"gG: 10 A (500 V, 1 kA)","Of The Contactor With Added Electronically Optimized Auxiliary Switch Block Typical":"5 000 000"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/24af8a8250a12e13128dc0835b81a2a7.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=765443&mlfb=3RT2018-2XB42-2LA2","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT2018-2XB42-2LA2/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional second-source for 3RT2018-2XB42-2LA2?","answer":"No direct second-source cross-reference exists from Siemens. The 3RT2 series is the standard SIRIUS contactor line; this specific order code defines the DC coil voltage range and spring-terminal connection. A different order code within the 3RT2 S00 family would be the parametric equivalent if the coil voltage or terminal type differs."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2018-2XB42-2LA2","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/3RT2018-2XB42-2LA2 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}}