# Buried PVC conduit question



## Steel Raider

My father in law is building a garage next to his house and wants to put in a 50amp subpanel in the garage. What is the depth that the conduit has to be buried? I looked at 300.5 and it is sort of vague. Any help would be appreciated. His neighbor already ran the conduit from the house to the garage and its only down about 8" (1 1/2"). This doesn't seem right to me.

Oh, and is a subpanel considered a "service" as far as the code goes?


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## william1978

Thats not deep enough. What did you come up with?


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## william1978

It should be atleast 18" deep.


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## 480sparky

I don't see how T300.5 can be called vague. You simply draw two lines.... a vertical one in line with *Type of Wiring Method or Circuit*, and a horizontal one along *Location of Wiring Method or Circuit.* Where they meet is your answer.


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## Dennis Alwon

william1978 said:


> It should be atleast 18" deep.


It really depends on the conduit. I seriously doubt that they ran Rigid but if they did then the 8.5' is enough unless it is under the driveway. I bet the neighbor is not a licensed guy.


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## Bob Badger

Dennis Alwon said:


> It really depends on the conduit. I seriously doubt that they ran Rigid but if they did then the 8.5' is enough unless it is under the driveway. I bet the neighbor is not a licensed guy.


Eight an half feet?

Yeah that should do it. :laughing:


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## Dennis Alwon

Bob Badger said:


> Eight an half feet?
> 
> Yeah that should do it. :laughing:


I thought so also. :thumbup: I guess I was thinking about the .5 being a half of a foot. Duhhhh


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## Chris Kennedy

Steel Raider said:


> His neighbor already ran the conduit from the house to the garage





Bob Badger said:


> Eight an half feet?
> 
> Yeah that should do it. :laughing:


Your father in law lives next door to this guy???


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## Podagrower

Don't forget to strap that PVC in the ground.:whistling2:

I'm not kidding, there is no exception for strapping in the ground.


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## paul d.

sometimes , due to existing conditions encasing conduit in concrete will satisfy inspectors/ specs. we run into this problem a lot in water treatment plants.


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## rexowner

You may want to look at 225.39, specifically (D). You may
want to make it a 60A subpanel if a CB in the subpanel
is the disconnect in the building.


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## william1978

Dennis Alwon said:


> It really depends on the conduit. I seriously doubt that they ran Rigid but if they did then the 8.5' is enough unless it is under the driveway. I bet the neighbor is not a licensed guy.


 Yes that is correct but in the OP question he is talking about PVC conduit.


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## TOOL_5150

Chris Kennedy said:


> Your father in law lives next door to this guy???


That is a messy trench. I use to work with some operators that could step the trench, and excavate it so that it looked like it was done with a knife. Granted, It looks like the dirt is very soft, but it could have a better bevel.

~Matt


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## erics37

Chris Kennedy said:


> Your father in law lives next door to this guy???


Hey that trench looks deep enough to require proper shoring and support, per OSHA requirements. ::001_huh: lol


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## Steel Raider

Thanks for the replies. My father in laws neighbor is not an electrician, and my FIL isn't getting anything electrical in the garage now. He is just getting the conduit from the house to the garage before everything is backfilled. He is getting it inspected before it is covered. It didnt' seem deep enough to me, so I thought I would ask some people that would know more than me. I am not an installation type electrician. I guess you could call me a repair man; i work on DC cranes, VFD's, PLC's, and motor controls.

On another note; does the garage need its own ground rod, or not?


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## william1978

Steel Raider said:


> On another note; does the garage need its own ground rod, or not?


 Yes. Here where I live you would need 2 ground rods.


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## micromind

Funny how soils are different for different areas. Around here, I don't think I've ever had a ground rod test out at more than 5 ohms. 

Rob


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## william1978

micromind said:


> Funny how soils are different for different areas. Around here, I don't think I've ever had a ground rod test out at more than 5 ohms.
> 
> Rob


 Your correct here I don't think with 2 ground rods it still not below 25ohms.


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## billsnuff

office = new construction

earth ground = UFER :thumbsup: (20' #4 copper CEE)

no rods :no:


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## dmanola7

Steel Raider said:


> My father in law is building a garage next to his house and wants to put in a 50amp subpanel in the garage. What is the depth that the conduit has to be buried? I looked at 300.5 and it is sort of vague. Any help would be appreciated. His neighbor already ran the conduit from the house to the garage and its only down about 8" (1 1/2"). This doesn't seem right to me.
> 
> Oh, and is a subpanel considered a "service" as far as the code goes?


Look @ Column 3 on Table 300.5 Nonmetallic raceways listed for direct burial without concrete encasement or other approved raceways. The depth is 18". Thats if you are using PVC.


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## dmanola7

Steel Raider said:


> Thanks for the replies. My father in laws neighbor is not an electrician, and my FIL isn't getting anything electrical in the garage now. He is just getting the conduit from the house to the garage before everything is backfilled. He is getting it inspected before it is covered. It didnt' seem deep enough to me, so I thought I would ask some people that would know more than me. I am not an installation type electrician. I guess you could call me a repair man; i work on DC cranes, VFD's, PLC's, and motor controls.
> 
> On another note; does the garage need its own ground rod, or not?


The garage doesnt need a ground rod as long as you have them at the main service. The feeder you run to the garage will be enough grounding for the sub-panel


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## JohnJ0906

dmanola7 said:


> The garage doesnt need a ground rod as long as you have them at the main service. The feeder you run to the garage will be enough grounding for the sub-panel


 
If the garage is a seperate structure, it must have a grounding electrode of some sort. 250.32(A).
It does not nessarily _have _to be a ground rod - it could be a CCE.


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## manchestersparky

JohnJ0906 said:


> If the garage is a seperate structure, it must have a grounding electrode of some sort. 250.32(A).
> It does not necessarily _have _to be a ground rod - it could be a CCE.


Correct, and as a side note you still need to separate the neutral and the grounds,even though your installing a grounding electrode


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## william1978

JohnJ0906 said:


> If the garage is a seperate structure, it must have a grounding electrode of some sort. 250.32(A).
> It does not nessarily _have _to be a ground rod - it could be a CCE.





manchestersparky said:


> Correct, and as a side note you still need to separate the neutral and the grounds,even though your installing a grounding electrode


 I agree with both of you.


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## zen

this may not apply but i did a job in arizona and the inspector said i had to use ridged,,wrapped completely with 20 mil tape from one end to the other and 8.5 in. deep,,because the soil was so acidic


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## 480sparky

zen said:


> this may not apply but i did a job in arizona and the inspector said i had to use ridged,,wrapped completely with 20 mil tape from one end to the other and 8.5 in. deep,,because the soil was so acidic


 
Why not just use PVC coated rigid then?


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## zen

honestly?because the job was providing power to a new atm at a bank and i just wanted it to pass inspection and honestly cause i didnt know there was pvc coated ridged,,here in texas most of the time we bury everything 24 in. schedule 80 and call it done


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