HOLT Electricians Practice Exam 2025 - Free Electrician Certification Practice Questions and Study Guide

The type of wire that can handle a maximum operating temperature of 150 C is asbestos-covered type AF wire. This wire is specifically designed for high-temperature applications and utilizes asbestos as an insulating material, which is effective in resisting heat. Asbestos-covered wires are particularly useful in environments where high temperatures are expected, making them suitable for specific industrial applications.

Other types of wire have lower maximum operating temperature ratings. Thermoplastic wire, for instance, typically has an upper limit of around 90 C to 105 C, depending on the specific material used. Fiberglass wire can withstand higher temperatures than thermoplastic but generally doesn't reach the 150 C threshold. Aluminum wire, while it is widely used in electrical applications due to its conductivity, also does not have the high-temperature insulation capacity found in asbestos-covered wires. Therefore, asbestos-covered type AF wire is correctly identified as the wire capable of withstanding a maximum operating temperature of 150 C.