Journeyman Electrician Practice Exam 2026 - Free Electrician Practice Questions and Study Guide

The setting of an overload device to trip at 115 percent of the motor full-load current rating is primarily designed to allow for the normal starting current of the motor, which is typically higher than the full-load current. During startup, motors often draw a surge of current that can be significantly greater than their rated current, sometimes up to 600 percent or more for a brief period.

By configuring the overload device to trip at 115 percent, it ensures that the motor can start without tripping the overload protection, providing a safety margin that accommodates this higher starting current. This approach is crucial for reducing unnecessary interruptions during the normal operation of the motor while still ensuring that the device provides protection against sustained overload conditions that could lead to overheating and damage.