Home>Discussions>EXTERIORS>Buried PVC/Conduit Under Driveway
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wilddogs51
Buried PVC/Conduit Under Driveway

I would like to run 110v power underneath my driveway to a LV transformer powering a couple driveway lights embedded in a block wall. I know LV can be rather shallow but what is the recommended depth for 110v? I was thinking of using direct burial wire within a conduit. Any recommendations? Any crush concerns for the conduit?

Thanks.

canuk
Re: Buried PVC/Conduit Under Driveway

It might be better to locate the transformer at a receptacle and run the LV cable to the lights. The reason I recommend this is there usually aren't any code issues for running LV lighting .

Depending on where you live 18 inches might acceptable for depth for the conduit.

JLMCDANIEL
Re: Buried PVC/Conduit Under Driveway

In my area buried conduit with power must be 36" down.
Jack

kentvw
Re: Buried PVC/Conduit Under Driveway

Per 08 National Electrical Code:
Table 300.5

Residential driveways, parking areas used only for dwelling related purposes

18” for direct burial and all types of conduit listed for direct burial.

The exception to this is resi circuits 120volts or less, 20amps or less and GFCI protected can be 12”.

Wonder why it needs to be so deep in Jacks area? :eek: In no case does the NEC require more than 24” of cover.

Good to check with your local codes though.

canuk
Re: Buried PVC/Conduit Under Driveway
kentvw wrote:

Per 08 National Electrical Code:
Table 300.5

Residential driveways, parking areas used only for dwelling related purposes

18” for direct burial and all types of conduit listed for direct burial.

The exception to this is resi circuits 120volts or less, 20amps or less and GFCI protected can be 12”.

Wonder why it needs to be so deep in Jacks area? :eek: In no case does the NEC require more than 24” of cover.

Good to check with your local codes though.

Pretty much identical here ... even in the frozen tundra of the Great White North.;)

djohns
Re: Buried PVC/Conduit Under Driveway

Here's something to consider . If you run the 120v ckt. under the driveway , you won't have the voltage drop issue to deal with . Low voltage lighting works best with short runs of wire and a healthy voltage supply . Your original post sounds like a sound idea .

canuk
Re: Buried PVC/Conduit Under Driveway
djohns wrote:

Here's something to consider . If you run the 120v ckt. under the driveway , you won't have the voltage drop issue to deal with . Low voltage lighting works best with short runs of wire and a healthy voltage supply . Your original post sounds like a sound idea .

True ... I guess it would depend on how far of a run for the LV cable and the type of transformer used.
The suggestion of running the LV cable instead of 120v would be simpler to deal with if the circumstance allowed.

Here's some good info. :http://www.outdoorlighting.learnabout.info/articles/83-low-voltage-lights.htm

canuk
Re: Buried PVC/Conduit Under Driveway

Are you talking about the 24 foot length or the narrower width?

JLMCDANIEL
Re: Buried PVC/Conduit Under Driveway
kentvw wrote:

Per 08 National Electrical Code:
Table 300.5

Residential driveways, parking areas used only for dwelling related purposes

18” for direct burial and all types of conduit listed for direct burial.

The exception to this is resi circuits 120volts or less, 20amps or less and GFCI protected can be 12”.

Wonder why it needs to be so deep in Jacks area? :eek: In no case does the NEC require more than 24” of cover.

Good to check with your local codes though.

That's what the building inspector said to run power to my shop.
I learned a long time ago that NEC doesn't mean a lot locally. I was installing some equipment at an asphalt plant in another state, the electrical inspector said it didn't meet code, I showed him the NEC requirements and explained that we exceed all of them and he said "I don't get a damn what the NEC says in this state we require it this way!" Needless to say I had to redesign, no ticky no worky no checky.
Jack

A. Spruce
Re: Buried PVC/Conduit Under Driveway
JLMCDANIEL wrote:

the electrical inspector said it didn't meet code, I showed him the NEC requirements and explained that we exceed all of them and he said "I don't get a damn what the NEC says in this state we require it this way!"

Unfortunately, all states, all counties, all cities, and some inspectors are this way. Ultimately, it is the inspector's discretion as to how to interpret the intent of the code, within the guidelines of their jurisdiction. I've worked in half a dozen different counties and cities in this state and every single one of them have peculiarities that are unique unto themselves. Code is a nice guideline, but just know the natives will have a difference of opinion. :D

Sort of on this subject, has anyone noticed a difference in the ease/difficulty in procuring permits depending on the size of the municipality and it's relation to civilization? Here where I live, you can write off at least 2 hours of your life - hating ever second of it - to get a permit for even the smallest of items, regardless of being in the city office or the county office. I've worked in other, more remote areas where I was in and out in less than 15 minutes (no exaggeration) and laughed and enjoyed my time with the fine folks behind the counter (again, no exaggeration).

That's it! I quit! I'm moving in with Goldie! :D:D He doesn't have to worry about such things. ;):D

JLMCDANIEL
Re: Buried PVC/Conduit Under Driveway

It's all politics. In the cities one of the primary functions of the building dept is to encourage the use of local contractors that pay taxes in the muni.

I lived in on city that required you to get a permit to replace your own water heater. I got the permit, replaced the water heater, called for inspection and it was red tagged. :eek: Called a friend of mine who was a contractor, he gave me a yellow city tag and said to hang it on the heater. I hung the tag and called the inspector , he saw the tag and said it passed. :confused: That's one of the reasons I now live in the country.:)
Jack

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