Which combination of moisture ingress signs best indicates moisture ingress?

• A. Condensation only
• B. Corrosion on contacts only
• C. Condensation, corrosion on contacts, and insulation degradation
• D. None of the above

Answer: (C)

Moisture ingress is best indicated when multiple moisture-related symptoms appear together. Condensation shows that water is present inside the enclosure, corrosion on contacts demonstrates electrochemical attack from moisture, and insulation degradation reveals the dielectric material being compromised by water. When all three signs—condensation, corrosion on contacts, and insulation degradation—coexist, it provides the strongest evidence that moisture has entered the system and is actively affecting materials and connections. Condensation alone could be temporary, corrosion alone might come from past exposure, and insulation degradation can result from aging or other factors, but the combination confirms ongoing moisture ingress.