HOLT Electricians Practice Exam

What is the maximum operating temperature of asbestos-covered type AF heat resistant wire?

1. 100 C

2. 150 C

3. 200 C

4. 250 C

The correct answer is: 150 C

The maximum operating temperature of asbestos-covered type AF heat resistant wire is 150°C. This type of wire is designed to withstand higher temperatures than typical insulation materials, which makes it suitable for applications where heat is a significant factor. Asbestos-covered wire was commonly used in situations with potential exposure to elevated temperatures, taking advantage of the heat resistance properties of asbestos insulation. The 150°C limit is established to ensure safety and performance; exceeding this temperature could lead to insulation degradation, potential electrical failures, or safety hazards. In comparison, other temperature ratings referenced in the options (100°C, 200°C, and 250°C) exceed or do not align with the specifications for asbestos-covered type AF wire. Understanding these temperature limits is crucial for electricians to ensure the longevity and safety of electrical systems.