Some users experience that the Follow sockets are no longer switched off, even though the main unit is switched off. The reason for this can be very high inrush currents of the connected Follow devices, which strongly exceed the max. load capacity of the relay and thereby weld the switch contacts.
In many cases, the switching contacts can be released from each other again by vibrations (knocking) and thus temporarily brought back into function. However, without a change in the configuration of the Follow devices, the problem usually reappears quickly.
Background:
Our automatic power strips, as a whole and the relays used in them, are designed for a continuous load with currents of 16A. End devices with a grounding plug are not allowed to draw more current than this. However, some terminal devices exceed this limit many times over at the moment of switching on. The current consumption can rise to 50A or more for a fraction of a second, for example. These high currents can cause welding of the switching contacts in the relay - the relay then no longer switches off.
Experience has shown that this problem occurs more frequently with terminal devices with switching power supplies. Nowadays these can be installed almost everywhere, e.g. PC, monitor, printer, external hard disks, active loudspeakers, etc.. Which products actually cause such problems also depends on whether the manufacturers of the end devices have taken appropriate measures against excessive inrush currents or not. Unfortunately, this cannot be read from any data sheet or type plate. We have optimized our automatic socket strips in this respect by using special relays for pulse loads of up to 80A. This means that the problem occurs much less frequently.