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SINAMICS S120

Siemens SINAMICS S120 is a modular drive and motion control platform within the SINAMICS family, designed for multi-axis servo and vector drive applications in CNC machine tools, production machinery, and high-performance industrial equipment. SINAMICS S120 uses a booksize modular architecture with a shared DC bus, combining an Active Line Module or Basic Line Module with individual Single Motor Modules or Double Motor Modules for each drive axis. The collection at PLC Direct includes S120 control units, single-motor modules, active interface modules, sensor modules, and accessories, totaling 688 products.

PLC Direct supplies Siemens SINAMICS S120 hardware to maintenance teams and procurement managers managing existing S120 drive installations. Our collection covers CU310-2 PN control units, Single Motor Modules, Active Interface Modules for Active Line Modules, and SMC20 sensor modules for encoder evaluation.

Where Siemens SINAMICS S120 Is Used

A failed SINAMICS S120 motor module or control unit on a servo axis takes that axis offline until a replacement with the correct current rating, firmware, and physical configuration is available. In multi-axis S120 drive systems, losing a single motor module on a shared DC bus can affect the broader drive lineup depending on the fault response configuration, and the time to repair is directly tied to parts availability. S120 hardware is also found in SIMOTION-based multi-axis systems and SINUMERIK CNC machines, where the drive system is tightly integrated with the motion control application.

Facilities that depend on Siemens SINAMICS S120 hardware include:

CNC machining centers and turning centers running SINAMICS S120 motor modules for axis and spindle drives, paired with SINUMERIK controllers
Multi-axis robotic and assembly systems with S120 drives controlling servo axes for positioning and velocity control.
Packaging and printing machinery using SINAMICS S120 as the drive backbone for SIMOTION-based motion control systems
Plastics processing equipment with S120-driven servo axes for injection, clamping, and extrusion operations
Metal forming and press lines with S120-controlled feed and forming axis drives.
Facilities maintaining long-term S120 installations where individual motor module or control unit replacements are required without full drive system upgrades

When an S120 motor module, control unit, or active front-end component needs to be replaced to restore a drive axis, having access to verified surplus sealed or refurbished stock outside standard OEM channels reduces the machine downtime window.

Siemens SINAMICS S120 Products

The SINAMICS S120 collection includes control units, single-motor modules, active interface modules, and sensor modules. All product families and model references below are confirmed on the live PLC Direct collection page.

Product Families

SINAMICS S120 Control Unit CU310-2 PN: Single-axis control unit for SINAMICS S120 drive systems with PROFINET interface. Confirmed in collection: 6SL3040-1LA01-0AA0, CU310-2 PN with PROFINET interface, supplied without CompactFlash card.
SINAMICS S120 Single Motor Modules (Booksize): Individual axis power modules in booksize format, providing DC bus to 3-phase AC output for one servo motor. Confirmed in collection: 6SL3120-1TE23-0AA3, 600 V DC input, 400 V 3 AC output, 30 A, booksize, internal air cooling, with optimized pulse patterns and extended Safety Integrated functions, includes DRIVE-CLiQ cable.
SINAMICS S120 Active Interface Modules: Active harmonic input filter modules for use with SINAMICS S120 Active Line Modules to meet line-side harmonic requirements. Confirmed in collection: 6SL3100-0BE25-5AB0, active interface module for 55 kW Active Line Module, input 3 AC 380-480 V, 50/60 Hz.
SINAMICS S120 Sensor Module SMC20: Booksize encoder evaluation module for SIN/COS 1 Vpp incremental encoders and EnDat absolute encoders, connecting via DRIVE-CLiQ to the S120 control unit. Confirmed in collection: 6SL3055-0AA00-5BA3, 30 mm booksize, without DRIVE-CLiQ cable.

Available at PLC Direct

SINAMICS S120 Control Unit CU310-2 PN, PROFINET, without CompactFlash card (6SL3040-1LA01-0AA0)
SINAMICS S120 Single Motor Module, booksize, 600 V DC / 400 V 3 AC, 30 A, internal cooling, with DRIVE-CLiQ cable (6SL3120-1TE23-0AA3)
SINAMICS S120 Active Interface Module for 55 kW Active Line Module, 3 AC 380-480 V, 50/60 Hz (6SL3100-0BE25-5AB0)
SINAMICS S120 Sensor Module SMC20, SIN/COS 1 Vpp / EnDat, booksize 30 mm, without DRIVE-CLiQ cable (6SL3055-0AA00-5BA3)

What to Know Before You Buy Siemens SINAMICS S120 Parts

Ordering the correct SINAMICS S120 component requires matching the module type, current rating, physical format (booksize or chassis), and DRIVE-CLiQ interface configuration to the installed drive system. S120 components are matched as a system; substituting mismatched modules can cause faults on the shared DC bus or prevent the drive axis from commissioning correctly.

Hardware condition options: PLC Direct supplies SINAMICS S120 hardware as surplus sealed, refurbished, and used. Surplus sealed units are factory-sealed stock; refurbished units have been tested and restored to operational condition.

Motor module current rating: The Single Motor Module (6SL3120-1TE23-0AA3) in this collection is rated at 30 A output. S120 motor modules are available in multiple current ratings, and the correct rating must match the motor's rated current and the original module specification. Installing an undersized motor module will cause overcurrent faults; an oversized module is electrically functional but represents an unnecessary cost.

CU310-2 PN CompactFlash card: The CU310-2 PN is supplied without a CompactFlash card. The CompactFlash card stores the drive firmware and project configuration. Either transfer the original CompactFlash from the replaced unit or source and load a CompactFlash card with the correct firmware version before the drive can be commissioned.

Active Interface Module sizing: The active interface module (6SL3100-0BE25-5AB0) is rated for use with a 55 kW Active Line Module. Active interface modules are sized to match the Active Line Module rating. Confirm the kW rating of the installed Active Line Module before ordering an active interface module replacement.

SMC20 DRIVE-CLiQ cable: The SMC20 sensor module is supplied without a DRIVE-CLiQ cable. A DRIVE-CLiQ cable of the correct length must be ordered separately to connect the SMC20 to the S120 control unit or motor module. Confirm the required cable length in the installed drive cabinet before ordering.

Lifecycle status of S120 hardware: The Single Motor Module (6SL3120-1TE23-0AA3) in this collection carries PM490 (Start of final year of support) lifecycle status. The CU310-2 PN, active interface module, and SMC20 carry PM300 (Active Product) status. Parts approaching the end of support should be identified for potential inventory stocking to ensure continued availability for future maintenance needs.

Warranty: All Siemens SINAMICS S120 hardware purchased from PLC Direct includes a standard 1-year warranty covering defects and functionality, applicable to surplus sealed, refurbished, and used products.

Frequently Asked Questions

PLC Direct carries SINAMICS S120 components, including CU310-2 PN control units with PROFINET interface, Single Motor Modules (booksize, 30 A), Active Interface Modules for 55 kW Active Line Modules, and SMC20 sensor modules for SIN/COS 1 Vpp and EnDat encoder evaluation. The collection includes 688 products. Contact us with your specific part number to confirm current availability.

SINAMICS S120 uses a shared DC bus architecture in which an infeed module (Active Line Module or Basic Line Module) converts the AC supply to DC, and individual motor modules convert the DC bus voltage back to variable-frequency AC to control each servo axis. A control unit (such as the CU310-2 PN) manages the drive’s control functions and communicates with the automation controller. All modules in a booksize S120 system are connected via DRIVE-CLiQ for configuration and feedback data. Sensor modules, such as the SMC20, connect encoder feedback to the S120 system when the motor lacks an integrated DRIVE-CLiQ encoder.

SINAMICS S120 is a multi-axis servo and vector drive platform for motion control, CNC, and high-dynamic machine applications, using a shared DC bus, booksize, or chassis-format architecture. SINAMICS G120 is a single-axis general-purpose industrial inverter for pump, fan, and conveyor applications. The two platforms use different control units, power modules, and accessories, and are not interchangeable. S120 is the correct platform for servo axis control; G120 is the correct platform for variable-speed motor control in standard industrial applications.

The SINAMICS S120 SMC20 sensor module (6SL3055-0AA00-5BA3) supports SIN/COS 1 Vpp incremental encoders and EnDat absolute encoders. It is used in S120 systems where the connected motor lacks an integrated DRIVE-CLiQ encoder interface, requiring an external encoder evaluation module. The SMC20 connects to the S120 control unit via DRIVE-CLiQ. It is supplied without a DRIVE-CLiQ cable.

The Single Motor Module (6SL3120-1TE23-0AA3) in this collection supports extended Safety Integrated functions. Safety Integrated in SINAMICS S120 includes functions such as STO (Safe Torque Off), SS1 (Safe Stop 1), SOS (Safe Operating Stop), and SLS (Safely Limited Speed), which are implemented within the drive without requiring external safety hardware for certain SIL levels. The availability of specific safety functions depends on the firmware version and the control unit configuration. Confirm the required safety function and its implementation requirements with the machine safety design before ordering.