A sure sign of contact failure is discoloration on the contact surfaces.

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Multiple Choice

A sure sign of contact failure is discoloration on the contact surfaces.

Discoloration on contact surfaces can indicate overheating or arcing, which are common clues related to how contacts are performing. However, it isn’t a definitive sign that the contact has failed. A contact can show some discoloration and still operate, and conversely, a failure can occur without any visible discoloration if there’s internal wear or a poor connection. So this symptom should be treated as a warning flag that prompts further check—like measuring contact resistance, inspecting for pitting or excessive wear, and verifying that the contact surfaces are clean and seating properly. If resistance is high or there’s noticeable damage, replacement is warranted.

Discoloration on contact surfaces can indicate overheating or arcing, which are common clues related to how contacts are performing. However, it isn’t a definitive sign that the contact has failed. A contact can show some discoloration and still operate, and conversely, a failure can occur without any visible discoloration if there’s internal wear or a poor connection. So this symptom should be treated as a warning flag that prompts further check—like measuring contact resistance, inspecting for pitting or excessive wear, and verifying that the contact surfaces are clean and seating properly. If resistance is high or there’s noticeable damage, replacement is warranted.

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