Grounding

[growler]

I saw something yesterday that I thought was strange and I'm sure that some of you work for the power companies. I was in another state visiting friends and as I started to leave something caught my eye. There was a ground wire running up the mast. It was connected to the neutral and bonded to the mast just under the weather-head with a ground clamp and then strapped to the pipe down to a ground rod. This was at a residence. They said that the power company did this. Is this a common method of grounding the transformer. I haven't noticed it before. Any thoughts.

 

[bphgravity]

Re: Grounding

The grounding of a service supplied A/C system can be made at any accessible point rom the service point to the the point the grounded service conductor is connected at the service disconnect. It appears a connection at the service point was made in your description.

 

[charlie]

Re: Grounding

I concur with Bryan.

 

[growler]

Re: Grounding

Not exactly my question. They can, but why. The power companies here don't do it that way. When I asked the homeowner, they said the lineman said it was better for lightning protection. I've never herd of this. But there are lots of things that I haven't herd of. I normally don't care much what happens on the supply side unless there's a problem. I was just fishing to see if there were any new theories out there. Much Thanks.

 

[bphgravity]

Re: Grounding

I'm not sure why the lineman had anything to do with this installation. Most utility companies only supply and connect the service conductors leaving the service grounding to the electrical contractor. What you are describing is for grounding the service not the utility side.

Connecting in this method may indeed provide better surge protection, but there is no real evidence for that. Perhaps the earlier the surge currents are diverted to ground, the less impact they may have on the system.

 

[physis]

Re: Grounding

By Bryan:

Connecting in this method may indeed provide better surge protection, but there is no real evidence for that. Perhaps the earlier the surge currents are diverted to ground, the less impact they may have on the system.

I'm not disagreeing. Being honest, when I did electronics I had the most trouble with understanding grounding considerations.

But, why would the ground point have a significant effect on surges? Even considering ground loops that aren't an issue in this case.

 

[charlie]

Re: Grounding

Consider this, lightning is looking for earth and the easier the path, the more likely that it will go there. If the path is outside the building then the building will more likely be better protected. If lightning has to go into a building before finding a path to earth, what damage will be done in the process?

I have heard for years that some electric utilities have actually made or required that connection at the service head but have never been told where. The stories have always pointed at the REMCs though.

 

[pierre]

Re: Grounding

Charlie

"Consider this, lightning is looking for earth and the easier the path, the more likely that it will go there."

I bolded this part of your statement.

Lightning is not always looking for earth - planes hit by lightning are a good example that lightning is not looking for earth.

We direct lightning to earth for safety, but lightning is a monster who goes where he wants, almost whenever he wants.

Earth just happens to be lightning's largest and most often hit target.

 

[physis]

Re: Grounding

That's sensible enough. I guess I'm having a language problem. I was thinking of surge as in noise on the AC.