{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3VA1225-5FF42-0AD0","brand":"Siemens","brandSlug":"siemens","productSlug":"3VA1225-5FF42-0AD0","canonicalUrl":"https://aoctrl.com/siemens/3VA1225-5FF42-0AD0","factsUrl":"https://aoctrl.com/api/mcp/products/3VA1225-5FF42-0AD0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 3VA1225-5FF42-0AD0, 4-pole molded case circuit breaker, 125 A, TM240 thermal-magnetic release, line protection design.","salesMarkdown":"It carries 4 poles rated at a continuous 125 A, with a TM240 thermal-magnetic overcurrent release — meaning the thermal element is calibrated for a 240 A frame, but the breaker itself is the 125 A tap. That matters for selectivity: the TM240 release gives you a higher short-time withstand before the magnetic trip fires, so you can coordinate downstream breakers without nuisance upstream tripping. ## SCCR headroom by system voltage Short-circuit current ratings (SCCR) vary significantly with system voltage — a key detail when you're specifying for a transformer secondary or a generator tie. At 240 V this breaker interrupts 187 kA; at 415 V it's still 121 kA; at 440 V it drops to 75.6 kA; at 500 V it's 30 kA; and at 690 V it's 17 kA. For a 480 V panel in North America (common 277/480 V wye), the 30 kA at 500 V covers most service-entrance requirements. The 690 V figure (17 kA) is relevant for 600 V Canadian or marine installations — verify your available fault current against that number. ## Thermal derating — don't size by the 40 °C sticker alone The breaker carries 250 A continuously from 40 °C through 50 °C, but above that it derates linearly: 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C. If your panel ambient hits 60 °C (common in a packed enclosure with drives or transformers), you lose 13 A of headroom. Dimensions are 158 mm high × 140 mm wide × 70 mm deep — a standard 4-pole MCCB footprint for Siemens SENTRON 3VA2 frames. The design includes provision for 3 auxiliary switches (HQ type) if you need remote status.","metaTitle":"Siemens 3VA1225-5FF42-0AD0 SENTRON 4-Pole 125A MCCB, TM240","metaDescription":"Siemens SENTRON 3VA1225-5FF42-0AD0 molded case circuit breaker, 4-pole, 125 A, TM240 release. SCCR 187 kA at 240 V. Active production. Quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Molded Case Circuit Breakers (MCCB)"],"specifications":{"Depth":"70 mm","Width":"140 mm","Height":"158 mm","Maximum":"125 A","Minimum":"125 A","at 240 V":"187 kA","at 415 V":"121 kA","at 440 V":"75.6 kA","at 500 V":"30 kA","at 690 V":"17 kA","at 40 °C":"250 A","at 45 °C":"250 A","at 50 °C":"250 A","at 55 °C":"243 A","at 60 °C":"237 A","at 65 °C":"230 A","at 70 °C":"223 A","Depth [In]":"2.76 in","Width [In]":"5.51 in","Height [In]":"6.22 in","Trip Indicator":"No","Number Of Poles":"4","Voltage Trigger":"No","lifecycle_stage":"current","Product Brand Name":"SENTRON","Product Designation":"Molded case circuit breaker","Undervoltage Release":"No","Design Of The Product":"Line protection","Communication Function":"No","During Storage / Maximum":"80 °C","During Storage / Minimum":"-40 °C","power loss [W] / maximum":"57 W","During Operation / Maximum":"70 °C","During Operation / Minimum":"-25 °C","Other Measurement Function":"No","Of The Supplied Basic Switch":"3VA12255FF420AA0","Design Of The Auxiliary Switch":"3 auxiliary switches HQ","Ground-Fault Monitoring Version":"Without","Insulation Voltage / Rated Value":"800 V","Design Of The Overcurrent Release":"TM240","Design Of Short-Circuit Protection":"For switching power values in DC networks, see the 3VA molded case circuit breaker device manual; link to be found under Service & Support in the last chapter","protection class IP / on the front":"IP40","design of the N-conductor protection":"50%","Product Function / Grounding Protection":"No","operating voltage / at AC / rated value":"690 V","operating voltage / at DC / rated value":"600 V","reference code / according to IEC 81346-2":"Q","Product Extension / Optional / Motor Drive":"Yes","Protection Function Of The Overcurrent Release":"LI","number of CO contacts / for auxiliary contacts":"3","Of The Integrated Auxiliary Switch/Alarm Switch":"3VA9988-0AA12","Switching Capacity Class Of The Circuit Breaker":"M","Mechanical Service Life (Operating Cycles) / Typical":"20 000","Type Of Electrical Connection / For Main Current Circuit":"nut keeper kit on both ends","Arrangement Of Electrical Connectors / For Main Current Circuit":"Front terminal"}},"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=568712&mlfb=3VA1225-5FF42-0AD0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3VA1225-5FF42-0AD0/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3VA1225-5FF42-0AD0 and how is it quoted?","answer":"This part is sourced through independent distribution and quoted to order against an RFQ. Availability and current pricing are confirmed at quote time — submit an RFQ for your volume and delivery needs."},{"question":"What is the SCCR of 3VA1225-5FF42-0AD0 at 480 V?","answer":"At 500 V the SCCR is 30 kA, which covers the typical 480 V system. At 690 V it's 17 kA. For intermediate voltages, the 440 V rating is 75.6 kA and the 415 V rating is 121 kA."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3VA1225-5FF42-0AD0","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/3VA1225-5FF42-0AD0 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}}