{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA2318-8XB30-2BB4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA2318-8XB30-2BB4","canonicalUrl":"https://aoctrl.com/siemens/3RA2318-8XB30-2BB4","factsUrl":"https://aoctrl.com/api/mcp/products/3RA2318-8XB30-2BB4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RA2318-8XB30-2BB4 reversing contactor assembly, size S00, 7.5 kW at 400 V AC-3, 24 VDC coil, spring-loaded terminals, screw and snap-on mounting on 35 mm DIN rail.","salesMarkdown":"## Reversing contactor assembly — two contactors in one package The Siemens 3RA2318-8XB30-2BB4 is a SIRIUS reversing contactor assembly — a pre-wired pair of 3RT2018-2BB42 contactors in a single housing, mechanically interlocked so only one closes at a time. This is the standard way to reverse a three-phase motor without external interlock wiring. The 24 VDC coil uses spring-type terminals — no screwdriver needed for the control wiring. ## Size S00 — panel footprint and mounting Size S00 contactor frame: 90 mm wide, 84 mm high, 83 mm deep. Clearance to adjacent components: 6 mm upwards, forwards, downwards, and to the side; 0 mm backwards (the back of the assembly sits flush against the mounting surface). ## Termination and wiring — spring-loaded main and coil No re-torquing needed on thermal cycles — the spring maintains contact force. Mechanical life is 10 million operations typical. Maximum switching frequency in AC-3 duty is 750 operations per hour — adequate for most reversing applications like conveyors, hoists, and door drives where the cycle rate stays well below one start every five seconds. ## Duty ratings across voltages Rated power varies by line voltage: 3 hp at 200/208 V, 5 hp at 220/230 V, 10 hp at 460/480 V and 575/600 V. Current ratings: 14 A at 480 V, 11 A at 600 V. The AC-4 rating (plugging / inching duty) at 400 V is 5.5 kW — lower than AC-3 because of the higher thermal stress during reversing under load. Shock resistance: 11.4 g for 5 ms and 7.3 g for 10 ms in both AC and DC axes — the assembly survives typical industrial vibration and impact without contact bounce.","metaTitle":"Siemens 3RA2318-8XB30-2BB4 SIRIUS Reversing Contactor","metaDescription":"Siemens SIRIUS reversing contactor assembly 3RA2318-8XB30-2BB4, size S00, 7.5 kW at 400 V AC-3, spring-loaded terminals, 24 VDC coil.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"83 mm","Solid":"2x (0.5 ... 4 mm²)","Width":"90 mm","at AC":"11,4g / 5 ms, 7,3g / 10 ms","at DC":"11,4g / 5 ms, 7,3g / 10 ms","title":"3RA2318-8XB30-2BB4","Height":"84 mm","Upwards":"6 mm","Forwards":"6 mm","Backwards":"0 mm","Downwards":"6 mm","At The Side":"6 mm","description":"reversing contactor assembly, AC-3e/AC-3, 16 A, 7.5 kW / 400 V, 3-pole, 24 V DC, spring-loaded terminal, electrical and mechanical interlock","During Storage":"-55 ... +80 °C","Of Magnet Coil":"Spring-type terminals","at AC-3 maximum":"750 1/h","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","Fastening Method":"screw and snap-on mounting onto 35 mm standard mounting rail","at AC-3e maximum":"750 1/h","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","Solid Or Stranded":"2x (0.5 ... 2.5 mm²)","at DC rated value":"24 V","Product Brand Name":"SIRIUS","Product Designation":"Reversing contactor assembly","Of Contactor Typical":"10 000 000","at 400 V rated value":"7.5 kW","at 480 V rated value":"14 A","at 500 V rated value":"7.5 kW","at 600 V rated value":"11 A","at 690 V rated value":"7.5 kW","For Main Current Circuit":"spring-loaded terminals","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","1 Of The Supplied Contactor":"3RT2018-2BB42","2 Of The Supplied Contactor":"3RT2018-2BB42","at AC-3 rated value maximum":"690 V","at AC-3e rated value maximum":"690 V","at AC-4 at 400 V rated value":"5.5 kW","Substance Prohibitance (Date)":"10/01/2009","at AWG cables for main contacts":"1x (20 ... 12)","of the supplied RH assembly kit":"3RA2913-2AA2","For Auxiliary And Control Circuit":"spring-loaded terminals","Product Extension Auxiliary Switch":"Yes","Product Function Bus Communication":"Yes","With Type Of Assignment 2 Required":"gG NH 3NA, DIAZED 5SB, NEOZED 5SE: 25 A","closing power of magnet coil at DC":"4 W","holding power of magnet coil at DC":"4 W","At Contactor For Auxiliary Contacts":"Spring-type terminals","With Type Of Coordination 1 Required":"gG NH 3NA, DIAZED 5SB, NEOZED 5SE: 50 A","at AWG cables for auxiliary contacts":"2x (20 ... 14)","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 ... 1.5 mm²)","Number Of Poles For Main Current Circuit":"3","Contact Reliability Of Auxiliary Contacts":"< 1 error per 100 million operating cycles","with low demand rate according to SN 31920":"40 %","Finely Stranded Without Core End Processing":"2x (0.5 ... 1.5 mm²)","protocol is supported AS-Interface protocol":"No","with high demand rate according to SN 31920":"75 %","Type Of Voltage Of The Control Supply Voltage":"DC","contact rating of auxiliary contacts according to UL":"A600 / Q600","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","product function control circuit interface with IO link":"No","Of The Contactor With Added Auxiliary Switch Block Typical":"10 000 000","For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gG: 10 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/84cc1095b51ba8fbb82d7119f0cf97f2.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=427222&mlfb=3RA2318-8XB30-2BB4"},"ai":{"faq":[{"question":"What contactors are supplied inside the 3RA2318-8XB30-2BB4?","answer":"Two Siemens 3RT2018-2BB42 contactors are pre-mounted and mechanically interlocked."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA2318-8XB30-2BB4","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/3RA2318-8XB30-2BB4 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}