Siemens 6SL3120-2TE21-0AA4 Replacement for SINAMICS S120

Product Overview

Siemens 6SL3120-2TE21-0AA4 Replacement for SINAMICS S120: Smooth Transition & Legacy System Compatibility

The Siemens 6SL3120-2TE21-0AA4 is a Dual-Axis Motor Module within the SINAMICS S120 booksize drive system, rated at 10 A continuous output current per axis. As Siemens progressively revises and phases out earlier hardware revisions of the S120 booksize line, many facilities running coordinated multi-axis servo applications — including CNC machining centers, packaging lines, printing presses, and material-handling gantries — face the challenge of sourcing a verified replacement that preserves existing wiring, cabinet layout, and drive program integrity.

TOPNLMS supplies tested, shelf-ready units of the 6SL3120-2TE21-0AA4 with full traceability, enabling your engineering team to execute a controlled swap-out with minimal production interruption. Whether you are replacing a failed unit on an emergency basis or proactively stocking a critical spare, our inventory is inspected, function-verified, and dispatched within 24–48 hours of order confirmation.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful migration to the 6SL3120-2TE21-0AA4 rarely involves the motor module in isolation. In most S120 booksize installations, the module operates alongside a CU320-2 PN Control Unit or CU320-2 DP Control Unit, which manages axis coordination, safety functions, and fieldbus communication. If the control unit firmware is below V4.7, a firmware update via STARTER or Startdrive is recommended before commissioning the replacement module to ensure full parameter compatibility.

The DC bus architecture of the S120 booksize system means the 6SL3120-2TE21-0AA4 draws its intermediate circuit voltage from a shared Active Line Module (ALM) or Smart Line Module (SLM) — typically a 6SL3130-6AE21-0AB1 or similar ALM variant. Verifying that the line module’s rated DC bus current capacity covers the combined load of all connected motor modules after the swap is a standard pre-commissioning step.

On the motor side, the dual-axis module connects to servo motors via standard power and brake cables. If the existing installation uses 1FK7 or 1FT7 series synchronous servo motors, the existing motor power cables and DRIVE-CLiQ encoder cables can typically be reused without modification, significantly reducing rewiring labor. For installations where the encoder interface differs — for example, legacy resolvers or TTL encoders — a Sensor Module Cabinet-Mounted (SMC) such as the 6SL3055-0AA00-5BA0 may be required to bridge the signal interface.

Cabinet-level integration should also account for the 24 V DC control power supply feeding the booksize components. A SITOP PSU100S or equivalent stabilized 24 V supply with sufficient current headroom for the control unit, motor modules, and any connected Terminal Module (TM31 or TM41) for analog I/O expansion is standard practice in S120 retrofit projects.

For multi-axis systems where the original configuration included a 6SL3040-1MA01-0AA0 SINAMICS S120 CU320-2 CompactFlash Card with a stored drive object configuration, the card can be transferred directly to the replacement control unit, preserving axis parameterization and safety configurations and eliminating the need for full re-commissioning from scratch.

Where the retrofit scope extends to the HMI layer, existing SIMATIC HMI TP700 Comfort or TP1200 Comfort panels communicating over PROFINET retain full compatibility with the S120 drive system after module replacement, as the drive’s network identity and axis object structure remain unchanged.

Retrofit Guidance FAQ

Q: Can I reuse existing motor power cables and connectors?
A: Yes. The 6SL3120-2TE21-0AA4 uses the standard booksize X1/X2 motor power connector pinout. Existing cables for 1FK7, 1FT7, or compatible servo motors can be reconnected directly without modification.

Q: Do I need to re-parameterize the drive after swapping the module?
A: In most cases, no full re-parameterization is required. The CU320-2 retains the drive object configuration on its CompactFlash card. After physical installation, perform a firmware compatibility check and run the “Accept topology” step in STARTER or Startdrive. Minor parameter adjustments (e.g., p107, p108 motor data) may be needed if the replacement unit has a different hardware revision.

Q: Is PROFIBUS DP communication preserved after the swap?
A: Yes. The motor module itself does not terminate the fieldbus — communication is managed by the CU320-2 DP or PN control unit. Replacing the motor module has no impact on PROFIBUS DP or PROFINET addressing or telegram configuration.

Q: What is the physical installation clearance requirement?
A: The 6SL3120-2TE21-0AA4 follows the standard S120 booksize form factor. Ensure a minimum 100 mm clearance above and below the module for cooling airflow. No additional cabinet re-work is required if replacing a same-format booksize module.

Q: How do I verify the replacement unit before full production restart?
A: After installation, power up in a controlled sequence: line module first, then control unit, then motor modules. Use STARTER or Startdrive to verify drive topology recognition, check fault memory (r0945), and perform a no-load motor identification run (p1910) before reconnecting the mechanical load.

Q: Can this module replace a single-axis module if one axis is unused?
A: Yes, with configuration. The dual-axis module can be operated with only one axis active by disabling the unused drive object in the CU configuration. This is a common approach when a single-axis slot is unavailable and a dual-axis unit is the available replacement.

Warranty Assurance

Every 6SL3120-2TE21-0AA4 unit shipped by TOPNLMS is covered by a 12-month warranty from the date of delivery. Prior to dispatch, each unit undergoes a functional verification process including DC bus energization, DRIVE-CLiQ port communication check, and output stage integrity test. Units that do not pass verification are not shipped.

In the event of a warranty claim, our after-sales team responds within 1 business day. Confirmed defective units are replaced and dispatched within 5 business days. We support return shipping coordination for international orders and provide full documentation for customs clearance where required.

For procurement teams requiring additional assurance, we can provide inspection reports, test records, and shipment photos upon request prior to order confirmation. Bulk orders and standing purchase agreements for critical spare programs are accommodated with agreed lead times and reserved stock arrangements.

Orders are processed and dispatched from Xiamen, China, with DHL Express, FedEx International Priority, and UCP freight options available. Estimated transit times: 3–5 business days to most of Asia-Pacific and Europe; 5–7 business days to North America and the Middle East.