Partial quote...
So if your stage is located anywhere under high-tension power lines, I would REALLY be sure it's grounded via an 8-ft ground rod and properly bonded to your generator neutral/ground.
Oh, yes.
I believe it was late Summer 2005, on a request for production at a fair in a neighboring county. The original provider was unable to be there and was a last minute notice.
My friend called me to assist with his rig and off we go.
Upon arrival at the permanent concrete stage platform in front of the grandstands, I cast a wary eye at the HV towers overhead, not very far behind the platform, running parallel to the stage. The droop between the steel towers was at its lowest point in the stage area. Observing the insulators, I was fairly sure it was 138 kV (common in my area). It was a dual 3 phase circuit with lines on both sides of the towers.
I remarked to my friend about the situation and said this could be interesting and my concern about his 30 foot long lighting truss being affected by induction from the high voltage parallel lines. He said lets get moving on assembling the truss to the lifts.
The stage was about 4 feet high and we placed the crank lifts on the ground in front of the stage and attached the truss. We cranked the truss up to 6 feet above the stage level to attach lighting.
I went up on the stage to start the process and proceeded to receive a fairly good wallop on the truss.
That was enough for me. I told the boss we HAVE to get this truss grounded. The electricians working for the county fair were there connecting our cams for our distro and they were summoned to the front of the stage and ended up with #4 copper connected to the lifts and running to a good ground to take care of the issue.
I did not take the time to meter the truss to see what level of voltage was inducted. The rest of the day and evening was uneventful and went well. Yes, the ground conductors remained until the truss was brought back down.