What fault occurs when current flows in one direction through relay contacts?

When current flows in one direction through relay contacts, this situation can lead to cratered contacts. This phenomenon occurs as a result of arcing or excessive heat at the point of contact, which can happen when the contacts are closed while current is flowing in one direction. The arcing can cause material to be eroded from the contact surface, resulting in small pits or craters, which deteriorate the functionality of the relay over time.

The creation of cratered contacts can significantly impair the reliability of the relay function, as these imperfections can cause fluctuating resistance levels. Without corrections to the contacts, such relays may fail to operate reliably in their intended applications. Understanding this specific fault is crucial for anyone working with relays in electrical systems, as it underscores the importance of maintaining relay integrity to ensure consistent performance.