Fuji Electric 2MBI75N-120 IGBT Module – Obsolete 2MBI N-Series Spare Part

Technical Dossier

Product Details And Specifications

Fuji Electric 2MBI75N-120 IGBT Module – Obsolete 2MBI N-Series Spare Part

RFQ support for obsolete parts: Send the model number, required quantity and destination so DriveKNMS can confirm sourcing options before quotation.

Technical Specifications

Solving the Discontinued Hardware Crisis

The 2MBI75N-120 occupies the inverter bridge position in a wide range of industrial drive topologies. In a standard three-phase inverter, six IGBT switches control the output waveform delivered to the motor. The 2MBI75N-120, as a dual module, packages two of these switches into a single hermetically sealed unit. Its failure mode is typically catastrophic — a short-circuit or open-circuit condition that immediately disables the drive and halts the connected process.

Facilities that installed drive systems in the 1990s and 2000s using Fuji 2MBI N-Series modules now face a structural supply problem. Fuji Electric has transitioned its IGBT portfolio to the 2MBI-XS and RB-IGBT series, which are not pin-compatible with the 2MBI75N-120 footprint. Direct substitution is not possible without PCB-level redesign. For a plant engineer managing a 20-year-old drive system, this means the only viable path to continued operation — without a capital project — is sourcing original 2MBI75N-120 units from the secondary market.

Condition & Reliability Assurance

All 2MBI75N-120 units processed by DriveKNMS pass a structured 5-step inspection protocol before dispatch:

• Step 1 – Visual Inspection: Examination of the module housing, terminal pins, and base plate for mechanical damage, corrosion, or evidence of prior thermal stress (discoloration, resin cracking).
• Step 2 – Pin Integrity Check: Each collector, emitter, and gate pin is inspected under magnification for oxidation, bending, or cold-solder residue from prior installation.
• Step 3 – Electrolytic Capacitor Assessment (where applicable in associated assemblies): Modules returned from field service are checked for evidence of capacitor electrolyte migration onto the module substrate.
• Step 4 – Gate Drive Parameter Verification: Gate threshold voltage and leakage current are measured against the original Fuji Electric datasheet parameters.
• Step 5 – Thermal Interface Inspection: Base plate flatness and thermal compound residue are assessed to ensure proper heat transfer in the target application.

Units that do not pass all five steps are quarantined and not offered for sale.

Key Features for System Maintenance

Q: How should we manage long-term spare parts inventory for legacy IGBT modules?
A: For critical drives with no modern equivalent, industry practice recommends holding a minimum of two replacement modules per drive on-site. For facilities with multiple identical drives, a shared pool of four to six units is a standard buffer. IGBT modules stored in original packaging in a dry, temperature-controlled environment have a shelf life exceeding 10 years.

Q: Can you source multiple units for a planned maintenance program?
A: Yes. DriveKNMS supports bulk procurement for planned maintenance programs. Contact us with your quantity requirements and delivery schedule for a formal quotation.