There is a current overload when in a given part of the system the current exceeds that expected for normal operation.
This can have negative consequences as the conductor can warm up to melt or cause fire and short circuits.
Joule Effect h1>
The Joule effect or "Thermal effect" is the phenomenon whereby a conductor crossed by an electric current dissipates energy in the form of heat as a function of the intensity of the electric current passing through it.
It is named after physicist James Prescott Joule who observed it around 1855.