Over-current and overload are abnormal conditions occurring in a circuit. This article well explains the difference between over-current and overload.
Difference between over-current and overload
Any situation in which the current flow through a device or conductor exceeds the desired value is known as over current. Both overload and short circuit can cause excessive current flow. Over currents may heat or damage the device
Over-current, by definition, is the flow of an excessive current in a circuit due to overload or short circuit.
Overload is a abnormal situation during which the current drawn by the load exceeds the current that can be supplied by the source. In case of electric motors, overload is a situation at which the load inertia at the motor shaft is higher than the load inertia that the motor can drive.
An electric overload, by definition, is a situation during which the load drains more current than the desired value.