AS-Interface sections grow by address, and the 2XH64-0AA0 build of the SINAMICS G115D is what the heavy end of that growth looks like: 4 kW at 10.2 A rated in LO duty (20.4 A HO), taking mains through its gland while the two-wire trunk keeps carrying only the control conversation — the first fan-cooled node in the family.

What changes when an AS-i node starts needing a fan?

The airflow plan, not the control plan. The trunk conversation is identical to the small nodes — setpoint, status, faults — but the 425 x 240 x 169 mm FSB housing needs its fan intake kept clear, and the section mount should respect that from the start. In exchange, the node carries a genuinely heavy belt: 200%/3 s and 150%/57 s overload behind the 10.2 A rating, with the integrated C2 filter, 24 V PSU and 180 V DC brake chopper already inside the IP65/66 / UL Type 4X housing.

Why stay on AS-i at 4 kW instead of moving to PROFINET?

When the segment master owns the control logic and plant reporting is not the bottleneck — a common architecture on conveyor lines built around AS-i from the start. The 0AF0 build of the same 4 kW hardware swaps in PROFINET and EtherNet/IP on the identical 425 x 240 x 169 mm footprint when diagnostics need to reach the plant network, so the AS-i decision is reversible at the cost of a bolt pattern, not a rebuild.