Quote Originally Posted by GCE View Post
Aluminum gland plate is fine as it is non magnetic material and you will not get a heat build up due to eddie currents
Only happens on magnetic material
The one property of Aluminium, is that it generates eddie currents with changes in magnetic field, over and above the ability to absorb heat, and the reason that it is used in heatsink material in the electronics industry. Granted the strength of the magnetic field will influence the amount of heat generated by eddie currents. This property is not seen with steel, stainless steel and copper. In fact the steel is a good shielding material for radio waves and magnetic fields, as opposed to aluminium. However in this case that a 4 or 5 core goes through the plate, the sum of all currents in the phases will be zero, and no magnetic field will be created, however with single cable through the gland and the high currents you refer to, it will generate eddie currents. The amount of heat generated may be small enough that it may be ignored as normal operating temperature.