Siemens has an official migration guideline for MM440 → G120 — but there is no single "MM440 order number = G120 order number" table, because G120 uses a modular Power Module + Control Unit architecture. This guide walks through how Siemens structures the selection, and what to check before you commit.
Siemens provides an official migration guideline for replacing MICROMASTER 440 (MM440) with SINAMICS G120, specifically covering G120 configurations using CU240B-2, CU240E-2 or CU250S-2 Control Units (firmware ≥V4.6 in the Siemens support entry). Do not treat an MM440 order number as if it maps to one complete G120 order number. MICROMASTER 440 is an integrated legacy inverter; SINAMICS G120 is modular — a Power Module plus a Control Unit and, where required, separate operator panel / communication / I/O options.
Siemens announced type cancellation of the MICROMASTER 4 family effective October 1, 2019, with final product discontinuation scheduled for October 1, 2027. Siemens Industry Mall entries for MM440 order numbers can show the legacy product as discontinued and indicate that a successor product is available. The original MICROMASTER 440 family covered approximately 0.12 kW to 250 kW depending on constant-torque / variable-torque duty and voltage version.
The Siemens MM440 → G120 migration guideline states that the corresponding SINAMICS G120 power stage is based on the PM240 Power Module family. The migration guideline then combines the selected power module with one of the supported G120 Control Units.
| Legacy item | G120 migration element | Practical meaning |
|---|---|---|
| MICROMASTER 440 integrated inverter | PM240 / current PM240-family Power Module | Select power stage by supply voltage, motor current/power, overload and braking requirements |
| MM440 control electronics / I/O | CU240B-2 or CU240E-2 | General-purpose control migration; terminal and function assignments must be checked |
| MM440 application requiring more advanced control / encoder functions | CU250S-2 where applicable | Review encoder/application requirements and exact Siemens documentation before selection |
A direct table that invents a complete G120 order number for every 6SE6440 code would be misleading. Siemens' official migration approach is configuration-based — the old MM440 nameplate/order number identifies the electrical class, but the new G120 solution also depends on the selected Control Unit and options. We use real MM440 order numbers for search coverage below, but we don't invent exact G120 order-number pairings Siemens doesn't publish.
The following are real MICROMASTER 440 order-number examples visible in Siemens Industry Mall / support indexing. They're useful as search-entry points — the exact G120 configuration must still be selected from the Siemens migration process above, not read off this table.
| MM440 order number | Legacy description / family | Successor treatment |
|---|---|---|
| 6SE6440-2UC17-5AA0 | MM440, 1/3 AC 200–240 V family | Siemens Industry Mall marks the main product discontinued; successor available |
| 6SE6440-2UD22-2BA0 | MM440, 3 AC 380–480 V family | Siemens Industry Mall marks the main product discontinued; successor available |
| 6SE6440-2AD22-2BA0 | MM440 with built-in Class A filter, 3 AC family | Siemens Industry Mall marks the main product discontinued; successor available |
Siemens states in the migration guideline that the Power Modules corresponding to MICROMASTER MM440 are PM240 Power Modules. Selection must be based on actual electrical and application requirements, not just the old MM440 kW rating: supply voltage/phase, rated motor current and power, overload/duty requirement, frame size and cabinet space, integrated/external braking requirements, EMC/filter configuration. Current G120 hardware generations may use PM240-2 in relevant ranges — treat any historical PM240 reference as a starting point to verify, not an exact current PM240-2 order-number match.
| Control Unit | Use in migration | What must be checked |
|---|---|---|
| CU240B-2 | Supported by Siemens MM440 migration guideline | I/O count, communication version, safety functions and application needs |
| CU240E-2 | Supported by Siemens MM440 migration guideline | Terminal arrangement, communication interface and application requirements |
| CU250S-2 | Supported by Siemens MM440 migration guideline | Use where advanced functions / encoder-related application capability is needed; verify exact application |
Siemens explicitly compares the terminal arrangement of MICROMASTER MM440 with CU240B-2, CU240E-2 and CU250S-2 — a major reason this should be treated as a migration, not a terminal-for-terminal swap. On MM440, digital input functions could be assigned directly with parameters such as p0701 to p0706; the G120 CU2x0x-2 architecture uses a different function/interconnection concept, so existing I/O function must be re-established in the new Control Unit.
Siemens' migration documentation includes dedicated PROFIBUS DP considerations and notes that MICROMASTER MM4 and SINAMICS G120 support different communication versions / implementations. Review: existing bus type and MM440 communication module/interface, bus address and baud rate, telegram/process-data format, control word and status word use, PLC hardware configuration, and drive fault/status words used by the machine program.
Siemens' MM440 → G120 migration guide specifically discusses braking behavior. For MM440, the default configuration deactivates the braking resistor and activates the Vdcmax controller — dynamic-braking behavior must be deliberately recreated and checked on the G120, not assumed. Confirm: was an external braking resistor used, how often does the machine decelerate or regenerate, what deceleration time is required, and what braking chopper/resistor arrangement the selected G120 Power Module needs.
A mechanically and electrically correct G120 can still require PLC/hardware-configuration changes if the communication implementation changes.
The migration goal is to reproduce the machine function, not to copy MM440 parameter numbers. Before removing the old inverter, record the parameter set — especially motor nameplate data, command source / ON-OFF logic, speed/frequency setpoint source, acceleration and deceleration times, minimum/maximum frequency, current/torque limits, digital I/O functions, analog I/O scaling, braking/Vdcmax behavior, fieldbus configuration and application-specific logic.
The modular G120 architecture and newer PM240/PM240-2 mechanical designs mean cabinet fit should be checked, not assumed. Confirm overall dimensions, mounting points, ventilation clearances, line/motor cable routing and access to the Control Unit / operator panel.
Encoder-feedback applications · high dynamic performance or complex torque-control requirements · legacy PROFIBUS / USS integration · special braking / regenerative duty · tightly packed cabinets where frame dimensions are critical · MM440 option functions not present in the selected CU · OEM machines where the PLC program depends on specific MM440 telegrams, fault codes or terminal behavior.
| Original MM440 spare may be reasonable when | G120 migration may be better when |
|---|---|
| The machine must restart immediately | The machine has a long remaining service life |
| Exact 6SE6440 stock is available and verified | Long-term support / spare availability matters |
| PLC, wiring and commissioning changes are not acceptable | Engineering changes can be planned and validated |
| A validated machine configuration must be preserved temporarily | Multiple MM440 units are being standardized or modernized |
For a MICROMASTER 440 request, we present four separate checks: original MM440 availability (can the exact 6SE6440 order number still be sourced from China, and what's the realistic condition/source risk); the official Siemens migration path (Power Module + Control Unit family, per Siemens guidance); migration risk (I/O, fieldbus, braking, encoder, parameter and cabinet changes, identified before purchase); and — only where Siemens isn't mandatory and the application supports it — a technically suitable alternative.
Full MM440 order number beginning 6SE6440-... · drive nameplate photo · motor nameplate photo · input voltage/phase · motor current/power · application and required duty · existing PROFIBUS/USS/other communication · braking resistor information · encoder information if any · cabinet photo and dimensions where fit is critical · PLC model and electrical drawing if available · quantity and destination country.
Siemens — MICROMASTER 440, SINAMICS G120 (CU2x0x-2) Migration guideline, Entry ID 82169413, dated 2016-04-04, support.industry.siemens.com · Siemens — Type cancellation of MICROMASTER 4 family, Entry ID 109768220 · Siemens — Catalog DA 51.2: MICROMASTER 420/430/440, Entry 109746797 · Siemens — Industry Mall MM440 product records (6SE6440 order-number pages), mall.industry.siemens.com · Siemens — PM240-2 hardware / CU240B-2 and CU240E-2 documentation, current G120 hardware documentation.
Technical disclaimer: ElecBridge is an independent sourcing service and is not Siemens. This page summarizes Siemens' migration information for practical sourcing use and must not be presented as Siemens engineering approval. Final drive selection, power-module sizing, Control Unit selection, wiring, fieldbus integration, parameterization and commissioning must be verified for the actual motor, machine and control system.
Tell us the full MM440 order number and application — within 48 hours you get an honest migration judgment. Power Module, Control Unit, and what to verify before you order.
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