What does a heat-discolored wire insulation indicate?

• A. Normal aging with no issues
• B. Overheating and potential imminent failure
• C. External chemical exposure
• D. Low voltage condition

Answer: (B)

Heat-discolored wire insulation shows the conductor has overheated beyond what the insulation can safely tolerate. This points to excessive current, a loose or high-resistance connection, or another fault that causes heating; the heat damages the insulation and raises the risk of insulation failure or a fire. Normal aging wouldn’t typically produce scorch-like discoloration, external chemical exposure would alter appearance in different ways, and a low voltage condition by itself doesn’t cause heat discoloration. When you see this, treat it as a warning sign to stop, inspect the circuit for overloads, bad connections, or damaged wire, and replace or repair as needed to restore safe operation.