The STEbus specification allows up to 4 amps per board on the 5V rail.

A fully-populated STEbus backplane with 21 boards could thus take up to 84 amps.

The Arcom backplanes had many M4 threaded power terminals for attaching heavy-duty power cables.

Although it is unlikely that anyone will need so much current, it is wise to make sure power cables are thick and low-resistance to reduce power rail ripple from transient high currents.