Journeyman Electrician Practice Exam

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Prepare for the Journeyman Electrician Exam. Test your skills with multiple-choice questions designed to help you succeed. Each question comes with hints and detailed explanations to assist in your study process.

Practice this question and more.

For motors, if an overload device is set to trip at 115 percent of the motor full-load current rating, what is the purpose of this setting?

To prevent overheating
To enhance performance
To allow starting without tripping
To minimize energy consumption

The correct answer is: To allow starting without tripping

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.