{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2018-4LB42-0LA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2018-4LB42-0LA0","canonicalUrl":"https://aoctrl.com/siemens/3RT2018-4LB42-0LA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2018-4LB42-0LA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS contactor, 3RT2018-4LB42-0LA0, size S00, 24 VDC coil, extended operating range, screw and snap-on mounting.","salesMarkdown":"It mounts via screw or snap-on onto a 35 mm DIN rail per EN 60715, and the mounting position allows +/-180° rotation on a vertical surface plus +/-22.5° tilt forward or backward, giving flexibility in tight enclosures. The 24 VDC coil holds at the rated value, and the extended operating range (0.7 to 1.25 x Uc) means the contactor picks up reliably even if the control supply sags to about 17 V or rises to 30 V — useful on lines with long DC runs or shared power supplies. The size S00 frame keeps the footprint compact at 45 mm wide, 61 mm tall, and 117 mm deep, so it fits standard 4-inch deep enclosures without crowding wireways. Side-by-side mounting is allowed, with zero clearance on either side — no extra spacing needed between contactors in a row. The ring cable lug connection on the magnet coil means you need a ring terminal on the DC feed; plan for that in your wiring schedule. Auxiliary switch is built in, so you get one N.O./N.C. set without adding a separate block.","metaTitle":"Siemens SIRIUS 3RT2018-4LB42-0LA0 Contactor, 24 VDC Coil, Si","metaDescription":"Siemens SIRIUS 3RT2018-4LB42-0LA0 contactor, 24 VDC coil, size S00, extended operating range. Active production. Sourced to order. Depth 117 mm, width 45 mm.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"117 mm","Solid":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), 2x 4 mm²","Width":"45 mm","at DC":"7 ... 20 ms","Height":"61 mm","Upwards":"10 mm","Forwards":"10 mm","Downwards":"10 mm","Arcing Time":"10 ... 15 ms","At The Side":"6 mm","Rated Value":"24 V","Initial Value":"0.7","During Storage":"-55 ... +80 °C","Of Magnet Coil":"Ring cable lug connection","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 60715","Full-Scale Value":"1.25","Mounting Position":"+/-180° rotation possible on vertical mounting surface; can be tilted forward and backward by +/- 22.5° on vertical mounting surface","Size Of Contactor":"S00","Product Brand Name":"SIRIUS","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","Side-By-Side Mounting":"Yes","For Main Current Circuit":"Ring cable lug connection","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","Relative Humidity Minimum":"10 %","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","Of Auxiliary Circuit Rated Value":"6 kV","For Auxiliary And Control Circuit":"ring terminal lug connection","Function Module For Communication":"No","Product Function Bus Communication":"No","With Type Of Assignment 2 Required":"gG: 25A (690V,100kA), aM: 20A (690V,100kA), BS88: 25A (415V,80kA)","Without Load Current Share Typical":"4 W","closing power of magnet coil at DC":"13 W","holding power of magnet coil at DC":"4 W","At Contactor For Auxiliary Contacts":"Ring cable lug connection","With Type Of Coordination 1 Required":"gG: 50A (690V,100kA), aM: 25A (690V,100kA), BS88: 50A (415V,80kA)","operational current at AC-12 maximum":"10 A","at AC in hot operating state per pole":"2.2 W","number of NO contacts for main contacts":"3","reference code according to IEC 81346-2":"Q","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 %","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","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":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=188149&mlfb=3RT2018-4LB42-0LA0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT2018-4LB42-0LA0/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional second-source if I cannot get this exact order code?","answer":"The closest functional peer is the 3RT2018-2AB02-ZX95, which shares the same size S00 frame and 24 VDC coil but lacks the extended operating range and the ring cable lug connection. It will drop into the same DIN-rail footprint, but verify the coil pick-up voltage tolerance and the auxiliary wiring before committing the BOM line."},{"question":"Will it drop into a panel wired for a 3RT2018-2AB02-ZX95 without rewiring?","answer":"Yes, the footprint and DIN-rail mounting are identical, and both are size S00 with a 24 VDC coil. However, the 4LB42 variant uses a ring cable lug connection on the magnet coil instead of the screw terminal on the 2AB02, so you may need to change the coil wiring termination."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2018-4LB42-0LA0","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/3RT2018-4LB42-0LA0 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}}