When a Profibus line needs the lowest-cost 0.75 kW drive, what fits?

The 6SL3230-3YE10-0UP0 is the entry G120X for PROFIBUS DP: unfiltered and with no DC terminals, so it is the lowest price of the 0.75 kW group. PROFIBUS DP is onboard for a direct drop onto an existing Profibus network — no gateway. For industrial Ethernet use the PROFINET/EtherNet/IP variant; for serial or BMS buses use the USS/Modbus/BACnet variant.

If the cabinet provides EMC filtering, is an integrated filter wasted?

Here it is absent by design — unfiltered, for panels that already carry cabinet-level EMC or sites that do not require per-drive compliance. That keeps cost down, but it cannot accept a du/dt filter or braking chopper (no DC terminals), so choose it only for short, fixed cable runs.

What overload applies to 0.75 kW pump and fan duty?

Variable-torque loads run at Low Overload: 110% of rated current for 60 s. At 0.75 kW that is 2.1 A continuous, in a 73 x 232 x 209 mm IP20 FSA frame.