Which measurement indicates an insulation fault in a signal cable?

Which measurement indicates an insulation fault in a signal cable?

• A. Hissing sound
• B. No odor
• C. Burning smell
• D. Visible smoke

Answer: (C)

When a signal cable’s insulation starts to fail, the fault current can heat the insulation and may cause it to burn or smolder. A burning odor is a direct sign that the insulation is overheating and deteriorating, which is exactly what an insulation fault would produce. Other signs like a hissing sound aren’t reliable indicators of insulation failure, lack of odor isn’t helpful, and visible smoke, while serious, often appears afterdamage has progressed further. If you notice a burning smell, treat it as an urgent fault: stop work, de-energize the circuit, and inspect the cable and surroundings for damage.

When a signal cable’s insulation starts to fail, the fault current can heat the insulation and may cause it to burn or smolder. A burning odor is a direct sign that the insulation is overheating and deteriorating, which is exactly what an insulation fault would produce. Other signs like a hissing sound aren’t reliable indicators of insulation failure, lack of odor isn’t helpful, and visible smoke, while serious, often appears afterdamage has progressed further. If you notice a burning smell, treat it as an urgent fault: stop work, de-energize the circuit, and inspect the cable and surroundings for damage.