When inspecting electrical contacts, what are the signs they are bad?

When inspecting electrical contacts, what are the signs they are bad?

• A. Pitted or burned
• B. Discolored
• C. Springs are taut
• D. Makes sparks

Answer: (A)

Bad electrical contacts show damage on the contact surfaces, and the clearest sign is pitting or burning. Pits are tiny indentations from corrosion or overheating and indicate the surface has degraded, which raises resistance and can lead to further heating or arcing. Burning marks similarly point to heat damage from poor contact. Discoloration can occur from heat, but it isn’t as definitive a sign of compromised contact performance, since it can have multiple causes. If the springs are still taut, that suggests the mechanism is maintaining proper pressure and isn’t itself worn, so it doesn’t indicate bad contacts. Making sparks is a sign of arcing during operation, not a static indicator you’d see just by inspecting the contact surface, and while serious, it doesn’t prove the surface condition as clearly as pits or burn marks do.

Bad electrical contacts show damage on the contact surfaces, and the clearest sign is pitting or burning. Pits are tiny indentations from corrosion or overheating and indicate the surface has degraded, which raises resistance and can lead to further heating or arcing. Burning marks similarly point to heat damage from poor contact. Discoloration can occur from heat, but it isn’t as definitive a sign of compromised contact performance, since it can have multiple causes. If the springs are still taut, that suggests the mechanism is maintaining proper pressure and isn’t itself worn, so it doesn’t indicate bad contacts. Making sparks is a sign of arcing during operation, not a static indicator you’d see just by inspecting the contact surface, and while serious, it doesn’t prove the surface condition as clearly as pits or burn marks do.