Drive selection memo — 5.5 kW, 150% overload, PROFIBUS DP
The Siemens SINAMICS G120C order code 6SL3210-1KE21-3AP0 is a compact variable-frequency drive sized for a 5.5 kW motor on a 380-480 VAC three-phase supply, with a 150% overload capability for 3 seconds — enough to handle short-duration load spikes on conveyors or pumps without oversizing the drive frame. It integrates a class A EMC filter, Safe-Torque-Off, and PROFIBUS DP fieldbus onboard. The IP20 / UL Open Type enclosure means it mounts inside a control cabinet — not on the machine frame — and the FSB footprint (196 x 100 x 203 mm) fits standard backplate layouts with enough clearance for the integrated filter's heat dissipation.
I/O and fieldbus — what connects where
The I/O interface gives you 6 digital inputs, 2 digital outputs, 1 analog input, and 1 analog output — enough for basic speed setpoint, run/stop, and fault feedback without an add-on I/O module. PROFIBUS DP is the integrated fieldbus; if your line uses PROFINET, this variant won't communicate without a gateway or a different G120C order code. Safe-Torque-Off is wired through the terminal block per EN 61800-5-2 — verify the safety relay or PLC safe output can source the STO current draw (typically 10-20 mA per channel) before commissioning.