The SINAMICS G115D 6SL3520-0XH04-0AB0 is the 4 kW wall-mounted distributed drive in FSB frame — the highest-power variant within the FSB size class and the point where the SINAMICS G115D series transitions from passive convection to integrated fan cooling. At 4 kW, natural convection through the IP65-sealed aluminum housing is no longer sufficient; the built-in fan sustains 10.2 A rated output current with 200% overload capability for 3 seconds at up to 40 °C ambient. PROFINET with PROFIsafe enables Safe Torque Off over Ethernet without dedicated safety wiring.

Why does the 4 kW FSB need a fan when 3 kW does not?

Within the FSB frame (425 × 180 mm footprint), the 2.2 kW and 3 kW variants dissipate heat through passive natural convection — the aluminum housing surface area is sufficient for those power levels. At 4 kW, heat loss exceeds what passive cooling can manage, so Siemens integrates a fan without changing the frame dimensions. This means the 4 kW FSB shares the same mounting pattern, motor connector interface, and M12 signal wiring as its fanless siblings — the only external difference is the fan grille. For conveyor system designers, this allows a single mechanical mounting design across 2.2–4 kW FSB products while upgrading cooling as power requirements increase.

What motors and gearboxes can it drive?

The 6SL3520-0XH04-0AB0 mounts directly to SIMOGEAR 2KJ8 geared motors in IE3 (asynchronous) or IE4 (synchronous reluctance) efficiency classes. Integrated 400 V AC brake control eliminates external brake contactors and rectifiers. Encoderless vector control supports both V/f mode for basic conveyor sections and sensorless vector control for precise acceleration and deceleration ramps. Dual-protocol PROFINET and EtherNet/IP on the same interface allows integration with both Siemens and third-party PLCs in mixed-vendor plants.

How does the FSB frame compare to FSA and FSC?

FSB (425 × 180 mm) sits between the compact FSA (380 × 216 × 129 mm, 0.37–1.5 kW, fanless only) and the larger FSC (425 × 240 × 169 mm, 5.5–7.5 kW, fan-cooled only). FSB is unique in offering both fanless (2.2–3 kW) and fan-cooled (4 kW) cooling within the same frame envelope. All three frame sizes share IP65/IP66 protection, wall-mounted installation, and the same SIMOGEAR 2KJ8 motor interface — upgrading power across frames requires no change to the conveyor mounting bracket or motor family.

Frequently Asked Questions

Can I replace a 3 kW fanless FSB with this 4 kW model on the same mounting?

Yes — the 4 kW FSB shares identical mounting dimensions with the 2.2 kW and 3 kW FSB variants. The only installation difference is ensuring adequate clearance for the fan intake and exhaust. Power wiring and motor connector (Q8/0) remain the same across all FSB power ratings.

Does the fan reduce the IP65 rating?

No — the fan is integrated behind the IP65-sealed housing. The protection rating applies to the complete assembly including the cooling fan. The drive remains suitable for dusty and washdown environments typical of conveyor installations in packaging and automotive assembly.