|  | 8.10 | Network Power Supply Issues: Power Line Problems
| 8.10.1 | Power problem classifications

There are three wires in a power cable, and problems that occur in the cable are labeled according to the particular wire(s) that are affected. If a situation exists between the hot and neutral wire, this is referred to as a normal mode problem. If a situation involves either the hot, or neutral wire, and the safety ground wire, it is referred to as a common mode problem.

As shown in the figure, the explanation of the power problem code is as follows. In the first line the brown dot indicates that the ground wire is not connected. In line two, the brown dot indicates that the neutral wire is not connected. In line three, no dot is indicated, showing that the hot wire is not connected. In the next two lines the blue and white dot indicate which lines are reversed, and the final line indicates that the line has no power connections problems.