The resetter is built to handle up to 15A 250V resistive loads (power factor 1) or 3000W. However in some countries the C13/C14 power connectors are not certified for more than 10A (2500VA).
These ratings are for resistive loads - you should take into account the power factor if you plan on using it with electrical motors for example. Most modern power supplies have
some form of Power Factor Correction and are compatible.
Some computer power supplies have very high inrush currents. Connecting several of them may result in hundreds of amperes load for a split second when they connect.
That will damage the relay inside the resetter - you will hear it click on restarts but the rig will not turn off. To avoid that use modern power supplies from reputable vendors -
most of them incorporate inrush current limiting and are safe to use. Do not connect too many power supplies to one resetter.
The device incorporates a 15A "software fuse". It will reset the load if it measures current above the maximum for a short time. This is only a software-based protection
and does not replace safety fuses.