{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3VA1225-4FF42-0AA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3VA1225-4FF42-0AA0","canonicalUrl":"https://aoctrl.com/siemens/3VA1225-4FF42-0AA0","factsUrl":"https://aoctrl.com/api/mcp/products/3VA1225-4FF42-0AA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 3VA1225-4FF42-0AA0, molded case circuit breaker, 4-pole, 125 A fixed rating, TM240 thermal-magnetic overcurrent release, line protection design.","salesMarkdown":"The fixed 125 A rating means you don't adjust it; you size the feeder for that number and the breaker holds it. ## Breaking capacity — what the curve tells you This MCCB delivers 121 kA interrupting capacity at 240 V, dropping to 75.6 kA at 415 V, 52.5 kA at 440 V, 17 kA at 500 V, and 11.9 kA at 690 V. That's a steep derating as voltage climbs — common for a thermal-magnetic breaker. At 240 V it handles high fault currents typical of North American 120/240 V split-phase services; at 400 V class it still clears 75.6 kA, which covers most industrial distribution transformers up to about 2 MVA. ## Thermal derating — don't ignore the ambient curve At 55 °C it derates to 243 A, then 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C. If the panel sits in a hot mezzanine or near a furnace line, that 223 A at 70 °C is your real limit — not the nameplate 125 A. Dimensions are 140 mm wide, 158 mm high, 70 mm deep. The 4-pole body is wider than a 3-pole — check your DIN-rail or mounting-plate space before you cut the backpanel.","metaTitle":"Siemens 3VA1225-4FF42-0AA0 SENTRON MCCB, 125 A, 4-Pole, TM24","metaDescription":"Siemens 3VA1225-4FF42-0AA0 SENTRON molded case circuit breaker, 125 A fixed rating, 4-pole, TM240 thermal-magnetic release. Breaking capacity 121 kA at 240 V. Quoted to order again","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","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":"121 kA","at 415 V":"75.6 kA","at 440 V":"52.5 kA","at 500 V":"17 kA","at 690 V":"11.9 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","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":"0","Switching Capacity Class Of The Circuit Breaker":"S","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":"https://cdn.aoctrl.com/da6846d0836660dcb00b94084c2e49d7.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=14442&mlfb=3VA1225-4FF42-0AA0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3VA1225-4FF42-0AA0/alternatives.json"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3VA1225-4FF42-0AA0","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/3VA1225-4FF42-0AA0 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}}