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.

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What is the ampacity limit for armored cable installed in thermal insulation in comparison to 60°C conductors?

It can exceed that of 60°C conductors
It shall equal that of 60°C conductors
It shall not exceed that of 60°C conductors
It must be less than that of 60°C conductors

The correct answer is: It shall not exceed that of 60°C conductors

The correct answer focuses on the ampacity limit for armored cable when it is installed in thermal insulation relative to that of conductors rated for 60°C. In this context, armored cables, when placed in thermal insulation, are subject to specific restrictions regarding their current-carrying capacity, known as ampacity. The reasoning behind this is based on the heat generated by the current flowing through the cables. Insulation can trap heat, leading to increased temperatures that can negatively affect the performance and safety of the electrical installation. Consequently, the National Electrical Code (NEC) stipulates that the ampacity rating for armored cables must be limited to ensure safety and to prevent overheating, which is why it cannot exceed that of conductors rated for 60°C. This limit is critical in ensuring the integrity and reliability of electrical systems installed in environments that may predispose conductors to higher operational temperatures. By adhering to this guideline, electricians maintain safety standards needed for effective and reliable electrical installations.