sharing a trench

[philhanna@comcast.net]

The Utility wants to share my trench. Their circuit is 12kv from the primary of their transformer and mine is 240V from the secondary. Section 300.3 (C) addresses different voltages in a single raceway, but I did not see anything addressing separation of raceways in a single trench. Any thoughts?

 

[Open Neutral]

CPUC has Joint Use Trench regs , as seen in PG&E's Greenbook

3.3.8. Installing Joint Utility Service Trenches

...if that helps. I assume other states do as well.

But I see a Mexican standoff; the utility is not regulated by your overlord; and you are not by theirs...

 

[hurk27]

If your responsible for the secondaries, I would want to be about a foot or more above their primaries for future repair, I would not want to be having to dig around their conductors to get at yours should a problem arise later on.

Other then that I see no problem as they (our POCO) do it all the time.

Here they even throw the yellow plastic gas line in the same trench to make it even more fun when you dig into it with a back hoe.

 

[kwired]

The Utility wants to share my trench. Their circuit is 12kv from the primary of their transformer and mine is 240V from the secondary. Section 300.3 (C) addresses different voltages in a single raceway, but I did not see anything addressing separation of raceways in a single trench. Any thoughts?

Think about this - how much separation do they need if above ground? Underground there is no physical damage unless excavating or if improper backfill was used.

How close together are non-insulated primary and secondary terminals on many pole mounted transformers?

 

[Open Neutral]

Is this

• an electrical engineering question..
• or a regulatory one

???

CPUC/PG&E wants 3" horz. between their primary and their secondary; but 12" diagonal between them and "a 2nd utility"....

I'd think the big regulatory issue would be mixing utility & non-utility users in the same trench at all.

 

[kwired]

Is this

• an electrical engineering question..
• or a regulatory one

???

CPUC/PG&E wants 3" horz. between their primary and their secondary; but 12" diagonal between them and "a 2nd utility"....

I'd think the big regulatory issue would be mixing utility & non-utility users in the same trench at all.

What is the difference when all said and done between a 4 foot wide trench with each utility installed at opposite sides or two 6 inch trenches spaced 4 feet apart?

 

[hurk27]

What is the difference when all said and done between a 4 foot wide trench with each utility installed at opposite sides or two 6 inch trenches spaced 4 feet apart?

The equipment you use to dig it

 

[Open Neutral]

The equipment you use to dig it

And a signifiant amount of dirt; do the numbers.