Screening for pole barn trench?

[gulf0927]

I know service conductors/conduits need 12" of screening on top, but drawing a blank on whether a subpanel trench needs one. Running 100' to a pole barn, soil is loose and mostly rock-free. PVC all the way. Don't know this particular AHJ very well.

 

[infinity]

Are you talking about the type of backfill? The NEC pretty much spells out what's required for service raceways or feeder and branch circuit raceways.

300.5(F) Backfill.
Backfill that contains large rocks, paving materials, cinders, large or sharply angular substances, or corrosive material shall not be placed in an excavation where materials may damage raceways, cables, conductors, or other substructures or prevent adequate compaction of fill or contribute to corrosion of raceways, cables, or other substructures. Where necessary to prevent physical damage to the raceway, cable, or conductor, protection shall be provided in the form of granular or selected material, suitable running boards, suitable sleeves, or other approved means.

 

[ramsy]

conduits need 12" of screening on top

Only if screening is solid concrete, then only 2" is required.

If screening is not solid concrete, then 18"-24" is typically required, per table 300.5

 

[electrofelon]

I know service conductors/conduits need 12" of screening on top.

Let me guess you heard this from the guy at Lowe's or home depot? . There is no such rule.

 

[gulf0927]

Let me guess you heard this from the guy at Lowe's or home depot? . There is no such rule.

My local power company actually. Why does everyone on this forum have such an attitude?

 

[gulf0927]

Are you talking about the type of backfill? The NEC pretty much spells out what's required for service raceways or feeder and branch circuit raceways.

Thanks! That answers my question, I'll dig in today.

 

[Hv&Lv]

My local power company actually. Why does everyone on this forum have such an attitude?

? Why is the local power company telling you how to backfill a ditch they have no control over?
I believe two words in 300.5 mater.. "when necessary"
Otherwise, backfil with what you have

 

[gulf0927]

? Why is the local power company telling you how to backfill a ditch they have no control over?
I believe two words in 300.5 mater.. "when necessary"
Otherwise, backfil with what you have

I was initially saying service conductors, like underground from the pole. They have their own regulations and that is one of them. But then I was asking about a feeder from the house to a pole barn, so was just wondering if their was any code I was missing before I backfilled with just dirt.

 

[kwired]

? Why is the local power company telling you how to backfill a ditch they have no control over?
I believe two words in 300.5 mater.. "when necessary"
Otherwise, backfil with what you have

Some POCO's around here the customer/contractor is often responsible for installing raceway from pole, pedestal, padmount, etc. to the structure as well as supplying meter socket at the structure. All of which some are fairly strict with how it is done and can exceed NEC minimum standards. NEC says it only needs to be 24 inches deep, POCO says it needs to be 36 inches deep. POCO may require long radius elbows, or schedule 80 all the way up a pole where NEC only would require it for 8 feet. POCO won't necessarily put a weatherhead on the raceway running up the pole though - make sense of that.

This same POCO will pull conductor through the raceway and per their service agreements they do take over maintaining this installation, but with their requirements they are betting all they will need to do if conductor goes bad is pull it out and pull a new one it. If some excavator damages it, they are the ones that will be responsible, financially anyway for repairs and if POCO doesn't want to excavate to repair they hire it out and charge to the one responsible for damage.

 

[Hv&Lv]

Some POCO's around here the customer/contractor is often responsible for installing raceway from pole, pedestal, padmount, etc. to the structure as well as supplying meter socket at the structure. All of which some are fairly strict with how it is done and can exceed NEC minimum standards. NEC says it only needs to be 24 inches deep, POCO says it needs to be 36 inches deep. POCO may require long radius elbows, or schedule 80 all the way up a pole where NEC only would require it for 8 feet. POCO won't necessarily put a weatherhead on the raceway running up the pole though - make sense of that.

This same POCO will pull conductor through the raceway and per their service agreements they do take over maintaining this installation, but with their requirements they are betting all they will need to do if conductor goes bad is pull it out and pull a new one it. If some excavator damages it, they are the ones that will be responsible, financially anyway for repairs and if POCO doesn't want to excavate to repair they hire it out and charge to the one responsible for damage.

We have the same requirements for customer installed services. We generally install our own.
A forever warranty is tough if you do t have say so in the installation..
I thought he was saying subpanel conductors..
I see his post now

 

[infinity]

I was initially saying service conductors, like underground from the pole. They have their own regulations and that is one of them. But then I was asking about a feeder from the house to a pole barn, so was just wondering if their was any code I was missing before I backfilled with just dirt.

Makes sense if the service conductors are under the utility control that they may have some say. For a feeder they would have no say so the NEC would apply.

 

[BarryO]

I know service conductors/conduits need 12" of screening on top

If they're service conductors it's outside the scope of the NEC, and it whatever the POCO says it needs to be. Typically around here they want a 3' deep open trench with 3" Schedule 80 PVC in place where the driveway will be. They place the conductors and the customer is then responsible for backfilling. If they let you get away with 12" you're getting off easy. Feeders to a pole barn is within the scope of the NEC, and just follow Table 300.5

 

[gulf0927]

If they're service conductors it's outside the scope of the NEC, and it whatever the POCO says it needs to be. Typically around here they want a 3' deep open trench with 3" Schedule 80 PVC in place where the driveway will be. They place the conductors and the customer is then responsible for backfilling. If they let you get away with 12" you're getting off easy. Feeders to a pole barn is within the scope of the NEC, and just follow Table 300.5

Appreciate it, this seems to be the consensus. Thanks for the help!!

 

[gulf0927]

Makes sense if the service conductors are under the utility control that they may have some say. For a feeder they would have no say so the NEC would apply.

Awesome, that's kinda what I was thinking but wanted to see what your experience was. Appreciate the help!

 

[kwired]

We have the same requirements for customer installed services. We generally install our own.
A forever warranty is tough if you do t have say so in the installation..
I thought he was saying subpanel conductors..
I see his post now

Sorry I got thrown off a little when he mentioned POCO told him how to do it, but apparently it is not something under POCO control either so any of their rules shouldn't apply.