The SINAMICS G115D 6SL3520-1XA21-5AF0 is the 1.5 kW wall-mounted distributed frequency converter in FSA frame with AS-Interface communication — the highest FSA power rating in the SINAMICS G115D series 1XA catalog designation. At 1.5 kW, the FSA frame (380 × 216 × 129 mm) still provides sufficient natural convection cooling without a fan — this is the ceiling of the FSA power range before stepping up to the larger FSB frame at 2.2 kW. It delivers 4.1 A rated output current with 200% overload for 3 seconds, driving IE3 asynchronous or IE4 synchronous reluctance motors via direct SIMOGEAR 2KJ8 geared motor mounting. AS-Interface AF0 connects the drive to any standard AS-i master over the two-wire yellow cable with 4-bit cyclic I/O, and STO is achieved via F-DI.

What makes the 1XA21 catalog designation notable?

The 1XA21 code covers 1.1–1.5 kW FSA in the 1XA catalog series — paralleling the 1XA01 designation for the same power range. Both 1XA01 and 1XA21 identify the same FSA hardware (380 × 216 × 129 mm, natural convection), supporting AA0, AF0, and AB0 communication variants. The co-existence of 1XA01 and 1XA21 for the same power range within the same 1XA series reflects internal Siemens catalog structuring — from the drive application perspective, they are functionally interchangeable.

Why choose AS-Interface at the FSA power ceiling?

At 1.5 kW — a common rating for mid-length belt conveyors and roller beds — AS-Interface provides a pragmatic communication solution for brownfield plants. The two-wire yellow AS-i cable daisy-chains from drive to drive, carrying both communication and 24 V DC auxiliary power. No Ethernet switches, no IP configuration, no additional network topology planning. For a conveyor line with five 1.5 kW drives spread across 50 meters, AS-Interface means five two-wire connections versus five Ethernet drops.

Frequently Asked Questions

Can I upgrade this drive to PROFINET later?

No — the communication interface is hardware-determined at order time. To migrate to PROFINET, replace with the AB0 variant. Motor, gearbox, and power connections remain unchanged.

How does STO work on this drive?

STO is achieved via the fail-safe digital input (F-DI) — a 24 V DC safety signal from an external safety relay or emergency stop circuit. SIL 2 / PL d compliant.