Please examine the wiring on the high voltage meter multiplier resistors usually located in the high voltage control cabinet. These resistors may be labeled R15 and R16 and are 15 megohm resistors.
A problem comes about when a high impulse primary line voltage spike causes a momentary high voltage spike that exceeds the voltage breakdown of the center to center spacing of these resistors. At these times, a short duration, high voltage arc can occur between the end of these adjacent horizontal resistors, causing high voltage to flow into the high voltage meter, destroying it and other items in it's path.
The cure for this problem is simple. Remove the connection that connects the two resistors together on the left end of both resistors. This connection is often a copper strap. Then add a short piece of high voltage wire between the output of the first resistor (on the left end) and bring it to the input end of the second resistor (on the right end). The original wiring looked like the letter "U" lying on it's side, the modified wiring will look like the letter "Z". The enclosed drawing will demonstrate this wiring change.
Thanks to the folks at Capitol Broadcasting in Raleigh, NC for spotting this elusive problem.
Details of modification of high voltage lead dress in high voltage metering circuit. This circuit is located in the high voltage control cabinet. This modification is to eliminate a problem with high voltage arcs due to close spacing of R15 and R16 meter multiplier resistors.
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