What type of protection must an overcurrent device provide in each ungrounded service conductor?

Overcurrent devices are essential in electrical systems as they play a crucial role in protecting circuits from overloads, short circuits, and ground faults. The correct answer focuses on overload protection, which is specifically designed to protect conductors from conditions where the current exceeds the rated capacity for an extended period of time.

When overload occurs, the circuit experiences excess current that can cause wires to heat up, potentially leading to insulation failure, fire hazards, or equipment damage. Overload protection devices, such as circuit breakers or fuses, are calibrated to detect this excessive current and interrupt the flow, effectively safeguarding the integrity of the electrical system.

Other types of protection mentioned have their specific applications but do not cover the required protection for ungrounded service conductors in the same way that overload protection does. Short-circuit protection is focused on immediate high-current events that occur in fault conditions, while ground fault protection addresses issues where current leaks to the ground. Voltage surge protection involves protecting against transient voltage spikes, which is unrelated to the continuous current overload scenario in this context. Therefore, overload protection is the requisite type of protection provided by an overcurrent device for each ungrounded service conductor.