Failed electric Trench? Not sure why

[stinkity stoink]

Ok I failed my inspection for my conduit in my trench. I am running 100 amp sub panel from my house to my garage. The run is about 75'. The trench is almost 2' deep. There is 1 elbow at the house and 1 elbow at the garage (underground) and 1 elbow for a turn in the pipe. There is an lb going into the house and garage. The lb at the house is about 2' above grade it goes into the house under an overhang. The lb at the garage goes in about 18" from the side enterance door and about 18" above grade (I wanted to landscape around garage and cover it with shrubs). I was not there when the inspector came ,but I recieved a dreaded red sticker. I failed he wrote on the sticker no rocks in the backfill granular material. Than it has what I assume is a code 300.5(D). I assume he wants me to put sand under and on top of the pipe. I spoke to a few electricians and they said occasionally inspectors want that. I am just trying to figure out what I might need to do so I can get inspected monday or tuesday. I want to close this up.

Thanks...

I ran PVC

 

[jmh21586]

They're picky about depth too.

 

[stinkity stoink]

I think my depth was good. I needed 18" ,but went a little bit further.

 

[LoneGunman]

I can't believe they'd fail it for lack of sand, I have never came across that. I don't know any electrical contractor that still drops sand in a trench.

 

[jmh21586]

I think inspectors are usually quite a bit pickier when it comes to do-it-yourselfers.

 

[stinkity stoink]

I am assuming that he wants sand in there. My buddy is an electrician and he says that is not the code ,but some guys are picky.

 

[deathbound]

Put sand in there & call for a re-inspection, period. You can try to fight if you think he's wrong, but may cause more problems for future inspections. Stay on his good side.

 

[stinkity stoink]

Thats what I was thinking. I don't want to argue with any of these guys. That is a no win. Just wasn't sure if there was any other problems he was talking about with the code #. Or with the height the conduit is entering the garage at.
I am screwed now though. It has been raining hard for a while. My trench is now a moat. It is about filled to the top.

 

[Rudyjr]

They do not like to see rocks in the fill material when the cable is direct burial.

 

[eddyyy302]

I am also in NJ, not sure where in NJ you are, but the inspectors here require sand in the trench for backfill as well. Our area is very rocky and they attribute the rocks in the trench as possibly doing damage to the conduit.

Dan

 

[stinkity stoink]

I asked 3 electricians and 1 told me some inspectors have made him do the sand .

 

[larry_g]

If the inspector signed the sticker then call him up and ask HIM. He is the one you have to please so he is the one to ask. This doesn't have to be confrontational, just calling to clear up what "I" need to do. During my build process I found that the inspectors were perty helpful in talking about upcoming inspections, or how to fix the failures I had. Our inspection office has the inspectors in the office to answer phone questions from 7-8am each day. They also post inspection reports online so you can see them.


lg
no neat sig line

 

[bradleys]

Does your electric utility have info about trench requirements for new service?

Even though you're not technically installing new service, it's likely that those requirements will be sufficient for your inspection.

Here's a link for a PDF with the requirements for Puget Sound Energy here in Washington. I realize that we're 3000 miles from you, but it's possible that these requirements are similar to what your requirements may be.

http://www.pse.com/SiteCollectionDocuments/builders/3061.pdf

I also agree about calling the inspector. Just give them an "I thought I had it figured - what did I miss?"

 

[stinkity stoink]

See I am worried about the 8' above grade part of that portion of the code. Not that it would be tough to fix ,but the place is sided right now.

The inspectors here seem to be part timers. Depends on which day you call on which inspector you get. I could be wrong though.

I am going to go to city hall monday and find out what they want. I will definiely not be confrontational. Just ask them what they want and I will do it.

Filling with a bunch of sand is going to be a hassle ,but I will get it done if thats what they want.

1996 National Electrical Code is all I have here, but I'll quote
300-5 (d) Protection from Damage. "Direct buried conductors and cables emerging from the ground shall be protected by enclosures or raceways extending from the minimum cover distance required by Section 300-5 (a) below grade to a point at least 8 ft (2.44 m) above finished grade. In no case shall the protection be required to exceed 18 in. (457 mm) below finished grade.
Conductors entering a building shall be protected to the point of entrance.
Where the enclosure or raceway is subject to physical damage, the conductors shall be installed in rigid metal conduit, Schedule 80 rigid nonmetallic conduit, or equivalent"

300-5 (a) simply says it must be 24" below grade. All electrical codes are read as a minimum requirement, they should just come out and say must be buried "at least 24 in."
Hope it helps

 

[Torque1st]

A little sand dumped along in the flooded trench then a little shake of the conduit should do the trick.

 

[Aceman]

They do not like to see rocks in the fill material when the cable is direct burial.

He's using pvc....

Does your electric utility have info about trench requirements for new service?

Even though you're not technically installing new service, it's likely that those requirements will be sufficient for your inspection.

I don't know what power co. requirements have to do with this at all? This is all NEC.

I've ran a lot of pvc underground and we've never bedded with sand either. I'll usually walk the trench once the pipe is layed in there and bed under the conduit to fill the low spots as well as knocking some of the high spots off. Smooth and straight pipe makes your job easier. I'll pull the big rocks out of the backfill if I see 'em.

 

[Torque1st]

The power utilities do not have to follow the NEC. Technically local government does not even have to adopt the NEC either. The Power companies do their own thing under "Engineering supervision" which is also allowed under the NEC.

 

[Norcal]

The power utilities do not have to follow the NEC. Technically local government does not even have to adopt the NEC either. The Power companies do their own thing under "Engineering supervision" which is also allowed under the NEC.

NEC does not cover anything under the control of utilities, they use the NESC & regs of the public utilities commission.

NESC: National Electric Safety Code.

 

[Torque1st]

That is correct.

 

[rasit]

If he only mentioned about the backfill material then what are you not sure about? I would take care of that (sand) and move on.

 

[elett]

Yes, He wants back fill 300.5 (F). Also Protection from Damage 300.5 (D) (1) He would want at least 18 inches below grade and anthing above grade to AT LEAST 8' protected by schedule 80 ridgid nonmetallic conduit or equivalent. That means anything from grade up to 8' if you had to go that high. Entering the buildings is not the issue. It sounds like you should be fine all you need is the back fill once the water is gone.

 

[stinkity stoink]

Thanks every one. I will let you know tomorow what he wanted. I hope

Thanks again

 

[Rudyjr]

The only PVC he mentions is where it turns up out of the trench and up and through the walls. Common method for protection in a direct burial service. If it were continuos PVC conduit I do not think it would be an issue.

He's using pvc....



I don't know what power co. requirements have to do with this at all? This is all NEC.

I've ran a lot of pvc underground and we've never bedded with sand either. I'll usually walk the trench once the pipe is layed in there and bed under the conduit to fill the low spots as well as knocking some of the high spots off. Smooth and straight pipe makes your job easier. I'll pull the big rocks out of the backfill if I see 'em.

 

[stinkity stoink]

Itis continious pvc 1- 1/2"

 

[Rudyjr]

My mistake I assumed it was direct burial with pvc risers on the end since he was bringing up rocks in the fill.I work for an electric utility and we don't get real picky about the fill when it is all pvc enclosed. No big rocks,bricks, block, etc.., allowed of course. So I guess you will have to ask him respectfully what exactly it is he doesn't like so you can correct it. Maybe he is just being over critical since its a DIY as someone else here stated.

 

[q miester]

IMHO the inspector is wanting the stubup at both ends to be either rigid or schedule 80pvc. I am assuming that currently the whole run is schedule 40. He wants it to run from at least 18" below grade to lb that is to protect the conductors. That is a easy fix. I would use schedule 80 pvc. i would stay away from the rigid (as that creates a whole grounding issue that we dont need to discuss here)

 

[rasit]

Ok I failed my inspection for my conduit in my trench. I was not there when the inspector came ,but I recieved a dreaded red sticker. I failed he wrote on the sticker no rocks in the backfill granular material.

Stinkity, is this the only thing he didn't like? Everybody is talking about the stub-ups the way I understood the original post was it was only about the issue of backfill. If you are also talking about the stub-ups I think the last post (q meister) nailed it.

 

[stinkity stoink]

I think the fill is the only issue. I went to the building dept. today and they couldn't give me an answer. I left a message for the inspector ,bit I wasn't able to talk to him.

I pulled the big rocks and boulders from the trench today. Than I dumped a yard of sand over ,under and around the pvc. I swept off the top of the pvc so it could still be seen hopefully it's good.

My pvc come up on both sides into an lb. It is all buried 18" or better. The only other problem would be if the lb doesn't come in high enough. I am not sure about that code he wrote down. The lb goes into the garage about 18" above grade and at the house about 2'. I just hope thats not a problem.

Thanks...

 

[Charles (in GA)]

300.5(D) has to do with direct buried cables. Says they must be protected from damage in accordance with 300.5(D)(1) thru (4).

(1) says that direct burial cables and ones specified in table 300.5 columns 1 and 4 only (thats direct burial and 120v/20amp residential buried branch circuits) have to be protected from damage where they emerge from grade.. at least 18" below grade to 8 ft above grade.

(2) says that conductors shall be protected at the point where they enter a building.

(3) says that UNDERGROUND SERVICE CONDUCTORS that are NOT encased in concrete and are buried 18 inches or deeper, must have a warning ribbon placed in the trench at least 12 inches above the underground installation.

(4) says that where the enclosure or raceway is subject to physical damage, then the enclosure or raceway must be in either rigid metal, intermediate metal, or schedule 80 PVC conduits.

It sounds like either (3) or (4) is the main concern. I'll bet its that ribbon in the trench.

Charles

 

[Aceman]

My pvc come up on both sides into an lb. It is all buried 18" or better. The only other problem would be if the lb doesn't come in high enough. I am not sure about that code he wrote down. The lb goes into the garage about 18" above grade and at the house about 2'. I just hope thats not a problem.

Your LB's are fine. I have had to stubup in sch. 80 many times due to possible physical damage issues. Physical damage is open to inspector interpretation.

300.5(D) has to do with direct buried cables. Says they must be protected from damage in accordance with 300.5(D)(1) thru (4).

(1) says that direct burial cables and ones specified in table 300.5 columns 1 and 4 only (thats direct burial and 120v/20amp residential buried branch circuits) have to be protected from damage where they emerge from grade.. at least 18" below grade to 8 ft above grade.

(2) says that conductors shall be protected at the point where they enter a building.

(3) says that UNDERGROUND SERVICE CONDUCTORS that are NOT encased in concrete and are buried 18 inches or deeper, must have a warning ribbon placed in the trench at least 12 inches above the underground installation.

(4) says that where the enclosure or raceway is subject to physical damage, then the enclosure or raceway must be in either rigid metal, intermediate metal, or schedule 80 PVC conduits.

It sounds like either (3) or (4) is the main concern. I'll bet its that ribbon in the trench.

Charles

It can't be (3), these aren't service wires, it's a feeder.

 

[Charles (in GA)]

It can't be (3), these aren't service wires, it's a feeder.

Yes, but you know, some inspectors.........

Charles

 

[shearhod]

240 v must be 3ft deep

 

[the spyder]

240 v must be 3ft deep

In what code? Its 18" here.

 

[stinkity stoink]

I passed today. His big concern was the rocks. There were a few I pulled out that were a baseball size or bigger. The sand was extra credit.

He also took a look at the framing to give me a heads up if I needed to do any thing . I thought that was pretty nice of him. He said it all looks good just a few minor things to finish up.

Thanks for the input every one.

 

[welderwink]

sometimes inspectors want the red tape that says "buried electrical line" on top of the conduit. but you passed so no worries.