The problem with the cable for the top VDC was not at the bottom of the rack at the union. It was at the terminal block in the VME breakout box. The wire at the relay common, C31, was not screwed down. The wire was loosely inserted in the terminal, but apparently had not been screwed down. Perhaps this aggravated the problem with the top VDC, where the foils were burnt through on the bottom side of the top VDC. I have set the Right Arm VDCs to 4kV. The VDCs on both arms should be ok to run, now.