Schneider Electric MT12N1 – 1250A Air Circuit Breaker | Masterpact NT/NW Series
Engineering Background: The Schneider Electric Masterpact series represents the global benchmark for low-voltage air circuit breakers in industrial power distribution. Designed to IEC 60947-2 and compliant with major international standards, the MT12N1 is engineered for mission-critical applications where reliability, arc-flash safety, and precise overcurrent protection are non-negotiable.
Product Positioning: The MT12N1 is a 1250A, 3-pole (or 4-pole configurable) fixed-mount air circuit breaker targeting main incomer, bus coupler, and feeder protection duties in MCC panels, distribution boards, and industrial switchgear assemblies. It is the preferred choice of procurement engineers specifying IEC-compliant protection devices for manufacturing plants, data centers, utilities, and infrastructure projects.
Complete Technical Specifications
- Model / SKU: MT12N1
- Brand: Schneider Electric
- Series: Masterpact NT / NW
- Rated Current (In): 1250 A
- Poles: 3P (4P available)
- Rated Voltage (Ue): 690 V AC / 250 V DC
- Rated Insulation Voltage (Ui): 1000 V
- Rated Impulse Withstand Voltage (Uimp): 12 kV
- Rated Short-Circuit Breaking Capacity (Icu): 42 kA @ 415 V AC
- Rated Service Short-Circuit Breaking Capacity (Ics): 100% Icu
- Rated Short-Time Withstand Current (Icw): 42 kA / 1 s
- Mounting Type: Fixed (drawout version available separately)
- Trip Unit: Micrologic electronic trip unit (configurable)
- Protection Functions: Long-time (Ir), Short-time (Isd), Instantaneous (Ii), Ground fault (optional)
- Standards: IEC 60947-2, EN 60947-2, GB 14048.2
- Degree of Protection: IP40 (front face, door-mounted)
- Operating Temperature: -25°C to +70°C
- Weight: ~21 kg
- HS Code: 8536.20
- Country of Origin: China (Schneider Electric manufacturing facility)
Proven Application Environments
- Main incomer protection in LV main distribution boards (MDB)
- Bus coupler duty in double-busbar switchgear
- Feeder protection for large motor control centers (MCC)
- Generator incomer and automatic transfer switch (ATS) panels
- Data center critical power distribution (Tier III / IV)
- Oil & gas, petrochemical, and mining plant electrical rooms
- Water treatment and utility substation LV switchgear
- Marine and offshore power distribution (with appropriate certification)
Engineering Advantages
- Micrologic Trip Unit: Fully electronic, field-adjustable protection curves — eliminates need for separate relay coordination studies in most applications
- 100% Ics Rating: Full rated service breaking capacity ensures no derating in service conditions
- Arc-Flash Mitigation: Zone-selective interlocking (ZSI) compatible — reduces arc-flash incident energy by up to 80% vs. time-delay coordination alone
- Drawout Interchangeability: Fixed and drawout chassis share identical footprint — future upgrade path without panel redesign
- Integrated Metering: Micrologic units provide real-time current, energy, and power quality data via Modbus / IEC 61850 (model-dependent)
- Long Service Life: Rated for 10,000 mechanical operations; contact wear indicator standard
System Architecture & Signal Flow
The MT12N1 sits at the incomer / main protection layer of a radial or ring LV distribution architecture:
- Upstream: MV/LV transformer secondary terminals or generator output terminals
- MT12N1 (this device): Main overcurrent, short-circuit, and earth-fault protection; metering point
- Downstream: Outgoing MCCBs (e.g., Schneider NSX/NSE series), MCBs, or sub-distribution boards
- Communication: Micrologic trip unit → Modbus RTU / Ethernet gateway → SCADA / BMS / EMS
- Interlocking: ZSI pilot wire to downstream feeders; mechanical / electrical interlocking with bus coupler ACB
Sourcing & Quality Verification
- Source: Authorized distribution channel — genuine Schneider Electric OEM product
- Traceability: Each unit ships with original Schneider Electric packaging, serial number, and factory test certificate
- Inspection: Pre-shipment visual inspection, continuity check, and trip-unit function verification performed by Konmask technical team
- Warranty: 12-month Konmask warranty; Schneider Electric manufacturer warranty applies per OEM terms
- Counterfeit Risk: Zero-tolerance policy — all units verified against Schneider Electric product authentication portal before dispatch
Procurement Process
- Inquiry: Submit RFQ via Konmask.com product page or email [email protected] with project quantity and delivery schedule
- Quotation: Formal quotation with lead time, unit price, and shipping terms issued within 1 business day
- Order Confirmation: Purchase order accepted; proforma invoice issued
- Payment: T/T bank transfer, L/C, or agreed credit terms for qualified accounts
- Inspection & Dispatch: Pre-shipment inspection report provided; DHL / FedEx / sea freight per buyer’s preference
- Documentation: Commercial invoice, packing list, certificate of origin, factory test certificate, and customs HS 8536.20 declaration
Technical FAQ
Q: Is the MT12N1 suitable for 400 V / 50 Hz systems?
A: Yes. Rated up to 690 V AC; fully compatible with 380–415 V, 50/60 Hz industrial systems.
Q: What is the difference between MT12N1 (fixed) and MT12N1 drawout?
A: The fixed version (this listing) is bolted directly to the panel busbar. The drawout version allows racking in/out without de-energizing the panel — specify at order stage if drawout chassis is required.
Q: Can the Micrologic trip unit be replaced in the field?
A: Yes. Micrologic trip units are plug-in replaceable without removing the breaker from the panel, enabling protection function upgrades without panel outage.
Q: What accessories are available?
A: Shunt trip (MX), undervoltage release (MN/MX), auxiliary contacts, alarm contacts, motor operator (MOE), remote reset, and communication modules (IFM, IFE Ethernet) are available — contact Konmask for accessory part numbers.
Q: Is a factory test certificate included?
A: Yes. Every MT12N1 unit supplied by Konmask includes the original Schneider Electric factory test certificate and product authentication documentation.
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