EC&M Article Questions

[Huffman]

I just read an article that was just posted on the EC&M website. It was about an electrocution at a carnival. I had a hard time understanding the article but it seemed like they were suggesting using a grounding electrode instead of a equipment grounding conductor. "free-hanging” green ground wire at the top of the pole to the ground rod at the base of the utility pole, it would have provided grounding, but not in compliance with standards.". Here is the article http://www.ecmweb.com/safety/monsters-midway


​[rbalex note: I created a link.]

 

[Coppersmith]

"When Dolence connected one test lead of his multimeter to the ride’s chassis and the other to the ground rod, he got a reading of 12.7V. Upon further investigation, he found two circuits improperly connected to a 20A breaker. When he removed one of the current-carrying conductors, the voltage reading disappeared. "

This is supposedly the reason for the electrocution in the article. I'm wondering if they meant to say "12.7 amps" since a stray voltage of 12.7 volts is not uncommon and probably not enough to feel a shock (although amperage would matter here). They don't say how the two circuits were improperly connected to the breaker. If it was double tapped, it may be a code violation, but should not be a source of electrocution. The loose wire they talk about later certainly could be the source.

 

[Coppersmith]

seemed like they were suggesting using a grounding electrode instead of a equipment grounding conductor.

They are saying the ground wire was not connected. Had it been connected to a ground rod at the bottom of the pole, the fault current would have a path to ground.

That may be true, but the earth is a high resistance path and may not have saved the day.

 

[Huffman]

They are saying the ground wire was not connected. Had it been connected to a ground rod at the bottom of the pole, the fault current would have a path to ground.

That may be true, but the earth is a high resistance path and may not have saved the day.

I think that this is a good example of how common it is, even in a very prominent magazine, for people to confuse a grounding electrode with an EGC. In this story I feel that the ground wire should have been bonded to the neutral or connected to a ground if the utility provided it, which is highly unlikely.

 

[ActionDave]

This is not the first ec&m article that is absolute garbage. I don't know who edits there but it is shameful.