Ground Rod

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GoldDigger

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Is a manhole a structure? Probably.
Are there junction boxes, devices or outlets in the manhole? Does it have more than one branch circuit going into it?
Sounds to me as if it needs a GES. A Ufer would be OK. :)
 

luckylerado

Senior Member
Is it a requirement for above 600v?
I do not think so but I am not 100% certain. Manholes are covered in 110 section V starting at 110.70 and I am very sure that a ground rod is not required and certainly not an GES. If a rod were installed it would be to bond the metal racks only and would not be tied to the EGC that pass through the enclosure. I see this done often for manholes that contain telecommunications splice cases.

Nearly all the manholes that I have ever installed are precast with bonding preinstalled. Measures less than 5 ohms to earth with a fall of potential meter by just setting it in the hole.
 

iwire

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Is a manhole a structure? Probably.
Are there junction boxes, devices or outlets in the manhole? Does it have more than one branch circuit going into it?
Sounds to me as if it needs a GES. A Ufer would be OK. :)

The key would be if a feeder is supplying the manhole, not just passing through.

If the manhole contains powered utilization equipment it might require a GES.
 

charlie b

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The key would be if a feeder is supplying the manhole, not just passing through. If the manhole contains powered utilization equipment it might require a GES.
What would you think about a set of dead break (or load break) junctions mounted on the manhole wall? Incoming power terminates there, and is taken away by connecting outgoing cables. That is not exactly "utilization equipment" you would have in the manhole, but our company's standard details show a ground rod within the manhole.

 

iwire

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What would you think about a set of dead break (or load break) junctions mounted on the manhole wall? Incoming power terminates there, and is taken away by connecting outgoing cables. That is not exactly "utilization equipment" you would have in the manhole, but our company's standard details show a ground rod within the manhole.



Code wise I think it is dependent on the AHJs veiw of what 'supplying' means.

My view is that unless there is powered utilization equipment in the structure the conductors are not supplying the structure.

That said I have very little experiance or code knowledge for systems over 600 volts
 
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