{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3VA1225-5FF42-0BC0","brand":"Siemens","brandSlug":"siemens","productSlug":"3VA1225-5FF42-0BC0","canonicalUrl":"https://aoctrl.com/siemens/3VA1225-5FF42-0BC0","factsUrl":"https://aoctrl.com/api/mcp/products/3VA1225-5FF42-0BC0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 3VA1225-5FF42-0BC0, molded case circuit breaker, 4-pole, 125 A, 187 kA at 240 V, line protection design, undervoltage release, 2 auxiliary switches.","salesMarkdown":"The Siemens 3VA1225-5FF42-0BC0 is a 4-pole SENTRON molded case circuit breaker rated at a solid 125 A continuous, with a short-circuit interrupting capacity of 187 kA at 240 V — that's the kind of muscle you need for high-fault utility feeds or transformer secondaries where a standard 65 kA breaker would weld shut on a dead short. Line protection design means it's set up for feeder and main breaker duty, not motor branch circuit protection — no adjustable overload relays here, just fixed thermal-magnetic trip curves sized for cable and bus protection. The interrupting rating drops as voltage climbs: 121 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V — so if your system runs 480 V or 600 V class, the 30 kA or 17 kA figure is the one your arc-flash study cares about. ## Thermal derating — the number that changes your wire size Above that, it starts to give: 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C. If your panel sits near a hot process line or a bank of drives, that 70 °C figure means you're still at nearly double the 125 A rating, so no practical derating issue for the intended load. It's a 4-pole frame so the width is 140 mm — that's about 5.5 inches of DIN rail or panel-mount space. Depth is 70 mm, height 158 mm. Standard SENTRON 3VA footprint, so if you're replacing an older 3VL or 3VF series, check the hole pattern; the 3VA family uses the same mounting centres as the 3VL but verify against your existing backplate drillings.","metaTitle":"Siemens 3VA1225-5FF42-0BC0 SENTRON MCCB, 4P 125A 187kA","metaDescription":"Siemens SENTRON 3VA1225-5FF42-0BC0 molded case circuit breaker, 4-pole, 125 A rated, 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":"Yes","Design Of The Product":"Line protection","Communication Function":"No","During Storage / Maximum":"80 °C","During Storage / Minimum":"-40 °C","power loss [W] / maximum":"59.5 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":"2 auxiliary switches HQ","Design Of The Auxiliary Release":"undervoltage release (UVR)","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%","Of The Integrated Auxiliary Trip Unit":"3VA9608-0BB11","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":"2","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=568719&mlfb=3VA1225-5FF42-0BC0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3VA1225-5FF42-0BC0/alternatives.json"},"ai":{"faq":[{"question":"What is the interrupting capacity of this breaker at 480 V?","answer":"At 500 V it's rated 30 kA, and at 440 V it's 75.6 kA — for a 480 V system the relevant figure is the 30 kA rating at 500 V (conservative for 480 V applications)."},{"question":"Does this MCCB include an undervoltage release?","answer":"Yes, it's factory-fitted with an undervoltage release (UVR) that trips the breaker on control power loss, plus two auxiliary switches for status feedback."},{"question":"Where can I buy 3VA1225-5FF42-0BC0 and how is it quoted?","answer":"This part is sourced to order against an RFQ through independent distribution. Availability and current pricing are confirmed at the time of quotation — no stock or price figures are published here."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3VA1225-5FF42-0BC0","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/3VA1225-5FF42-0BC0 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}}