{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RF2420-1AB45","brand":"Siemens","brandSlug":"siemens","productSlug":"3RF2420-1AB45","canonicalUrl":"https://aoctrl.com/siemens/3RF2420-1AB45","factsUrl":"https://aoctrl.com/api/mcp/products/3RF2420-1AB45","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS solid-state contactor, 3RF2420-1AB45, two-phase controlled, zero-point switching, 22 A AC-51, 45 mm width, screw terminals.","salesMarkdown":"## Solid-state contactor for resistive loads The zero-point switching means the thyristors fire at the voltage zero crossing, which minimizes inrush and electrical noise on the line. The 22 A AC-51 rating is the resistive load current — that's the number you use for heater banks, not motors. For motor or light inductive loads, you'd derate to the AC-53 curve (not listed here, but typical for this class). The minimum operational current is 500 mA, so it won't drop out on a small pilot load. The I²t maximum is 1 800 A²·s — that's the let-through energy the thyristors can handle during a short-circuit event before the upstream fuse clears. The evidence calls for a 3NA3805 fuse at 460 V, rated lower than the contactor itself, to protect the semiconductors. Wire it with screw terminals accepting 1x (0.5...2.5 mm²) solid or 2x (0.5...1.0 mm²) stranded. Control side draws 30 mA at 24 VDC nominal, with a 22 mA holding current. The DC control circuit is isolated from the main contacts — 7 mm clearance between them — so you can drive it from a PLC output without worrying about power-circuit noise coupling back. 45 mm wide, 100 mm tall, 117 mm deep — it takes up one standard DIN module width. Side-by-side mounting is allowed, but watch the 44 W heat dissipation and the 40 °C derating point. The UL 508 rating is 15 A — that's the US listing limit, which is lower than the IEC AC-51 rating. If your panel needs UL 508 compliance, size it at 15 A, not 22 A.","metaTitle":"Siemens 3RF2420-1AB45 SIRIUS solid-state contactor, 22 A AC-","metaDescription":"Siemens SIRIUS 3RF2420-1AB45 solid-state contactor, 22 A AC-51, two-phase controlled, zero-point switching, 45 mm wide, current production. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Solid State Relays"],"specifications":{"Depth":"117 mm","Solid":"1x (0.5 ... 2.5 mm²), 2x (0.5 ... 1.0 mm²)","Width":"45 mm","at DC":"22 mA","Height":"100 mm","at 50 Hz":"40 ... 660 V","at 60 Hz":"40 ... 660 V","up to 460 V":"3NA3805; These fuses have a smaller rated current than the semiconductor relays ; These fuses have a smaller rated current than the semiconductor relays","ON-delay time":"1 ms; additionally max. one half-wave","During Storage":"-55 ... +80 °C","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","Fastening Method":"screw fixing and snap-on mounting on standard mounting rail 35 mm according to IEC 60715","Product Function":"zero-point switching","For Main Contacts":"7 mm","I2t value maximum":"1 800 A²·s","Solid Or Stranded":"0.5 ... 2.5 mm²","at DC rated value":"30 V","Product Brand Name":"SIRIUS","Degree Of Pollution":"3","Product Designation":"solid-state contactor","Derating Temperature":"40 °C","at 50 Hz rated value":"48 ... 600 V","at 60 Hz rated value":"48 ... 600 V","at AC-51 rated value":"22 A","Design Of The Product":"two-phase controlled","Side-By-Side Mounting":"Yes","For Main Current Circuit":"screw-type terminals","Operational Current Minimum":"500 mA","at AC in hot operating state":"44 W","Substance Prohibitance (Date)":"07/01/2006","Insulation Voltage Rated Value":"600 V","Operating Frequency Rated Value":"50 ... 60 Hz","according to UL 508 rated value":"15 A","at AWG cables for main contacts":"2x (14 ... 10)","Reverse Current Of The Thyristor":"10 mA","For Auxiliary And Control Circuit":"screw-type terminals","control current at DC rated value":"30 mA","For Auxiliary And Control Contacts":"7 mm","Without Load Current Share Typical":"0.9 W","at AC-51 according to IEC 60947-4-3":"15 A","Surge Current Resistance Rated Value":"600 A","Symmetrical Line Frequency Tolerance":"5 Hz","Of The Auxiliary And Control Contacts":"M3","at AC in hot operating state per pole":"14.67 W","reference code according to EN 61346-2":"Q","due to burst according to IEC 61000-4-4":"2 kV / 5 kHz behavior criterion 2","number of NC contacts for main contacts":"0","number of NO contacts for main contacts":"2","reference code according to IEC 81346-2":"Q","Finely Stranded With Core End Processing":"1x (0.5 ... 2.5 mm²), 2x (0.5 ... 1.0 mm²)","Number Of Poles For Main Current Circuit":"3","2 Of The Accessories That Can Be Ordered":"converter","Finely Stranded Without Core End Processing":"1x (0.5 ... 2.5 mm²), 2x (0.5 ... 1.0 mm²)","For Main Contacts With Screw-Type Terminals":"18 ... 22 lbf·in","at DC initial value for signal <1> detection":"4 V","number of CO contacts for auxiliary contacts":"0","number of NC contacts for auxiliary contacts":"0","number of NO contacts for auxiliary contacts":"0","shock resistance according to IEC 60068-2-27":"15g / 11 ms","Type Of Voltage Of The Control Supply Voltage":"DC","vibration resistance according to IEC 60068-2-6":"2g","at AWG cables for auxiliary and control contacts":"1x (AWG 20 ... 12)","at DC full-scale value for signal<0> recognition":"1 V","electrostatic discharge according to IEC 61000-4-2":"4 kV contact discharging / 8 kV air discharging, behavior criterion 2","Surge Voltage Resistance Of Main Circuit Rated Value":"6 kV","Installation Altitude At Height Above Sea Level Maximum":"1 000 m","conducted HF interference emissions according to CISPR11":"Class A for industrial environment","Relative Symmetrical Tolerance Of The Operating Frequency":"10 %","field-bound HF interference emission according to CISPR11":"Class A for industrial environment","Design Of The Thread Of The Screw For Securing The Equipment":"M4","For Auxiliary And Control Contacts With Screw-Type Terminals":"7.5 ... 5.3 lbf·in","Blocking Voltage At The Thyristor For Main Contacts Maximum Permissible":"1 200 V","of back-up R fuse link for semiconductor protection at NH design usable":"3NE8015-1","AWG number as coded connectable conductor cross section for main contacts":"14 ... 10","of full range R fuse link for semiconductor protection at NH design usable":"3NE1814-0","Rate Of Voltage Rise At The Thyristor For Main Contacts Maximum Permissible":"1 000 V/µs","of full range R fuse link for semiconductor protection at cylindrical design usable":"5SE1320; Maximum operating voltage 400 V! ; Maximum operating voltage 400 V!","of back-up R fuse link for semiconductor protection at cylindrical design 10 x 38 mm usable":"3NC1032","of back-up R fuse link for semiconductor protection at cylindrical design 14 x 51 mm usable":"3NC1450","of back-up R fuse link for semiconductor protection at cylindrical design 22 x 58 mm usable":"3NC2250"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$277.00","priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=360450&mlfb=3RF2420-1AB45","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RF2420-1AB45/alternatives.json"},"ai":{"faq":[{"question":"What is the AC-51 rated current for this contactor?","answer":"The AC-51 rated current is 22 A. AC-51 covers resistive loads with minimal inrush, like heater elements."},{"question":"What wire sizes does the screw terminal accept?","answer":"The main circuit screw terminals accept 1x (0.5 to 2.5 mm²) solid or stranded, or 2x (0.5 to 1.0 mm²) stranded. For AWG, that's 2x (14 to 10) for the main contacts."},{"question":"What is the physical size of this contactor?","answer":"It is 45 mm wide, 100 mm high, and 117 mm deep. It mounts on a 35 mm DIN rail per IEC 60715 or can be screw-fixed to a panel."},{"question":"Does this part have a UL rating?","answer":"Yes, the UL 508 rated current is 15 A. This is lower than the IEC AC-51 rating of 22 A, so for UL-listed panels, design to 15 A."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RF2420-1AB45","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/3RF2420-1AB45 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}}