A main transport belt that stalls with product on it costs more than the drive that moves it, and the fault is hard to find when nothing on the drive reports it. This 4 kW SINAMICS G115D unit is fed on its own run, reports over PROFINET or EtherNet/IP, and is rated 10.2 A continuous at 380-480 V with 20.4 A available for the three seconds a loaded start takes.

Does a conveyor drive need its own power feed, or can it be chained?

This variant is the individually fed one: power arrives on a single MQ15 connector and there is no second connector to loop through, so each section keeps its own feed and a section that loses power points at one plug rather than at a chain of them. Where looping is wanted it exists in the N0 section of the same family, as on the 0.37 kW unit 6SL3520-2XN00-3AA0 with its two Q4/2 connectors wired for daisy chaining.

For the panel that means one cable per section, sized on the 8.95 A this frame draws from the line, with no pass-through current to allow for in the connector or the cable. The 24 V for the drive control electronics is integrated as well, so a line with a dozen wall-mounted units loses a dozen sets of terminals, a fuse group and the wiring between them.

Is 3 kW or 4 kW the right frame for this belt?

The 3 kW version 6SL3520-2XM03-0AF0 is rated 7.7 A in a 425 x 240 x 134 mm housing at 7.97 kg and rejects its heat by natural convection. In a dusty hall that is the property which decides the argument: no impeller, no filter mat and nothing that pulls the environment through the drive.

The 4 kW frame delivers 10.2 A but grows to 425 x 240 x 169 mm, weighs 8.37 kg and needs a fan with a clear airflow path. It is the right step when the belt itself gets heavier, with more product carried or a slight incline, rather than when the same belt carries a heavier load.

The overload window is what tempts people to stay one size down: 200% of the base load current for 3 s and 150% for 57 s inside a 300 s cycle lets a 7.7 A drive put 15.4 A into a jam for three seconds. A section that starts and stops on every cycle spends that allowance on its transients, and then the continuous rating is what should decide the frame.

Once the belt runs: what the network adds and what needs attention

PROFINET or EtherNet/IP arrives on an M12 socket, so state, current and fault codes reach the controller and a stop can be attributed to a drive rather than to an area. Both protocols share the same control board, which means one spare unit covers either network on a site where lines were built in different years.

What needs attention is the airflow path of the fan-cooled versions: dust on the impeller or a blocked inlet shows up first as a rising drive temperature rather than as a fault. The rest is designed to be left alone, with IP65/IP66 and UL Type 4X protection, a range of -30 to +55 C, the category C2 filter inside the drive, up to 15 m of screened motor cable and the PE connection made at the housing with an M5 screw.

When the drive does report an overload, Siemens documents A07805 (power unit overload I2t) with the remedy to reduce the continuous load. In practice it comes from a belt heavier than the sizing assumed or from a jam that never cleared, so the first checks are mechanical: roller bearings, accumulation pressure, and the current drawn against the 8.95 A supply figure.