Mike,
Recently we were called to a sportsplex about complaints of chain link fence shocking people. At first I thought that this was impossible, here we have multiple fence post buried in the ground every 10' apart , and a wet soil also. On arrival I placed 1 probe to fence and 1 to earth....there it was 100VAC to ground.
We then thought that one of the post must be in direct contact with a live wire. We proceeded to locate circuit by turning off individual light circuits to field lights and found the circuit that was causing problem. The circuit was feeding 3 80' lighting poles each with 2 separate circuits for lighting 2 separate ball fields. To make a long story shorter, eventually one of my employees leaned on one of the concrete light poles,and after a few unmentionable words informed me that the pole live. The pole has metal climbing inserts encased in concrete and all metal common to each other. The pole is buried 15' in the ground making it what I considered a good rod.
Upon placing probe to earth and metal on pole I read 277V. I placed a 2/0 insulated wire to metal and it would draw an arch to ground.
I disconnected the 3 phase at the base of pole and turned circuits back on, all was clear. We disconnected the circuit at top of pole and found that problem is shorted wiring in pole.
Question is: Why was this much voltage getting to fence which was 10' away?
Recently we were called to a sportsplex about complaints of chain link fence shocking people. At first I thought that this was impossible, here we have multiple fence post buried in the ground every 10' apart , and a wet soil also. On arrival I placed 1 probe to fence and 1 to earth....there it was 100VAC to ground.
We then thought that one of the post must be in direct contact with a live wire. We proceeded to locate circuit by turning off individual light circuits to field lights and found the circuit that was causing problem. The circuit was feeding 3 80' lighting poles each with 2 separate circuits for lighting 2 separate ball fields. To make a long story shorter, eventually one of my employees leaned on one of the concrete light poles,and after a few unmentionable words informed me that the pole live. The pole has metal climbing inserts encased in concrete and all metal common to each other. The pole is buried 15' in the ground making it what I considered a good rod.
Upon placing probe to earth and metal on pole I read 277V. I placed a 2/0 insulated wire to metal and it would draw an arch to ground.
I disconnected the 3 phase at the base of pole and turned circuits back on, all was clear. We disconnected the circuit at top of pole and found that problem is shorted wiring in pole.
Question is: Why was this much voltage getting to fence which was 10' away?
