Which of the following defines an 'overload' in the context of electrical motors?

In the context of electrical motors, an 'overload' refers specifically to a situation where the motor is subjected to excessive current due to a high load condition. This excessive current flows through the normal conductors of the motor, potentially causing the windings to overheat, leading to insulation breakdown and permanent damage. The motor is working harder than it was designed for because the load placed on it exceeds its rated capacity.

The correct answer identifies the essence of an overload condition, highlighting the cause (excessive current) and the context (high load) which are critical aspects in motor protection. Overloads are typically accounted for in motor protection schemes through the use of overload relays, which help prevent damage by disconnecting the motor when such conditions are detected.

While other options present different electrical issues, they do not accurately define an overload. For instance, a short circuit is a completely different phenomenon that usually involves a direct connection across a power source leading to a surge of current. An increase in voltage beyond design limits indicates a potentially hazardous overvoltage condition, while temporary conditions leading to system failure might refer to a transient event rather than sustained excessive current associated with an overload. Thus, the definition centered on excessive current from a high load is the most