The Siemens 6SL3121-2TE15-0AA3 is a SINAMICS S120 Double Motor Module — a booksize-format drive component that takes a 600 V DC link input and delivers 400 V three-phase AC output at 5 A per axis, for a total of 5 A/5 A across two motor channels. The booksize form factor and external air cooling mean this module slots into a multi-axis drive cabinet alongside other S120 booksize units, sharing the DC bus and cooling infrastructure — no need to gut the whole line if you're replacing a failed module or expanding an existing S120 build.
The 600 V DC input is the standard SINAMICS S120 DC-link voltage for a 400 V AC supply after rectification — it's not a standalone AC input, so this module must be fed from a regulated DC bus, typically from a Smart Line Module or Basic Line Module. At 5 A per axis (two independent motor outputs), this module is sized for small servo or induction motors — think feed axes, spindle drives under 2-3 kW, or dual-motor applications like a synchronized pair of conveyor rollers. The 5 A/5 A rating means both channels can run at full current simultaneously, not derated. Optimized pulse patterns and extended Safety Integrated functions (including DRIVE-CLiQ cabling for encoder feedback and safety communication) are built in — no separate safety module needed for basic safe torque off or safe stop 1 on both axes.
Integration notes
The booksize construction (roughly 50 mm wide per axis pair, standard S120 booksize height and depth) mounts on the mounting rail inside the cabinet, with external air cooling ducted through the rear heat sink. Verify your cabinet's cooling plenum matches the S120 booksize air duct pattern before ordering.