What will contacts look like in a contactor when the contactor should be replaced?

The appearance of contacts in a contactor can be a direct indicator of its condition and need for replacement. When contacts are worn thin or cratered out, this signifies that they have endured significant wear and tear during operation. Such signs typically result from the electrical arcing that occurs each time the contactor opens and closes. Over time, this pitting and wear can lead to poor electrical contact, which in turn can cause increased resistance, overheating, and eventual failure of the contactor.

Intact and shiny contacts suggest that the contactor is functioning well and has not experienced any significant wear or electrical stress. While contacts covered in rust and dirt can indicate neglect or a poor operating environment, they do not directly reflect the mechanical or electrical performance of the contactor in the same way as worn or damaged contacts. Lastly, overheating and discoloration are symptoms of an underlying problem but may not always correlate directly to the physical state of the contacts, as they can result from other issues such as overloads or poor connections, rather than just the physical condition of the contacts themselves.

Therefore, worn thin or cratered out contacts are a clear and direct indication of the necessity for replacement due to their compromised ability to establish a good electrical connection.