The 3 kW G115D under its XE4 catalog code, networked and fanless at once: 7.7 A continuous, 15.4 A for 3 s at 200% overload, natural convection in the 425x180x134 mm FSB housing, IP65/66, with PROFINET, PROFIsafe and EtherNet/IP over the hybrid cable.

What does natural convection save on a 3 kW section?

The whole fan upkeep list. A fan-cooled drive carries a filter that clogs and a bearing that wears - on a food or packaging line the air it pulls through itself carries the dust of the process, and that dust finds the filter. The fanless 3 kW step has neither part: heat leaves the housing on its own, silently, and the maintenance schedule for the drive drops to zero moving parts. The trade is the rating - 7.7 A continuous with 15.4 A for 3 s - so the choice is current against upkeep. Sections that fit inside the rating take the fanless drive and forget it; sections that outgrow it move to the 4 kW step and inherit the fan.

When does a 3 kW section join the PROFINET ring?

When the controller needs to see it. A section that only has to turn can stay on terminals forever; a section whose speed, current and faults the line must react to belongs on the network, and at 3 kW that network runs over the same hybrid cable that feeds the drive - no separate comms wiring, no extra switch between neighbors. The two M12 ports chain the drive into the line, and closing the ends into a ring means one damaged cable degrades nothing. Safety rides the same pair of wires as the data, and the integrated 175 ohm braking resistor takes the section's stop energy on short ramps.