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Thread: Conduit protection?

  1. #1
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    Conduit protection?

    Just recently installed an air cooled generator and had it inspected. The 3/4" conduit from the residence to the generator goes underground. I used schedule 80 conduit at each end where it comes out of the ground. The Inspector said I needed to protect the conduit riser at the generator end from lawnmower/trimmer damage. I thought that installing schedule 80 conduit was the protection. I plan on calling the Inspector to talk about it but just wanted other's opinions. If you had to protect the conduit, what would you do? I thought about sliding a section of 1 1/2" conduit over the existing conduit and let it stick out above ground about 8 inches. Thanks to all who reply.

  2. #2
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    You are right, the NEC considers schedule 80 to be suitable for use in areas subject to damage.

  3. #3
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    I agree with both of you.

    Here is what I found on a pvc manufacturers site. The regular PVC is just called Heavy Wall.

    PVC Rigid Nonmetallic Conduit (Extra Heavy Wall EPC-80)
    Listed for use in aboveground and belowground applications including areas subject to physical damage.
    Rated for use with 90°C conductors
    Superior weathering characteristics
    Identified for use in areas subject to physical damage in accordance to 352.12(C)
    494* Series
    1/2” – 6 ” Standard Radius and Special Radius Elbows available.


  4. #4
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    Maybe the inspector considers that area to be subject to severe physical damage.
    Don, Illinois
    "It is the first responsibility of every citizen to question authority." B Franklin

  5. #5
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    Quote Originally Posted by don_resqcapt19 View Post
    Maybe the inspector considers that area to be subject to severe physical damage.
    Not that this dictates fact, but Schedule 80 PVC is used throughout the country down a power pole to feed utility transformers underground. The generally carries 12KV cabling. And your inspector wants to deem a generator feed inadequately protected?


    I know what I don't know, and I know where to go to find it!

  6. #6
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    Quote Originally Posted by RESI View Post
    Just recently installed an air cooled generator and had it inspected. The 3/4" conduit from the residence to the generator goes underground. I used schedule 80 conduit at each end where it comes out of the ground. The Inspector said I needed to protect the conduit riser at the generator end from lawnmower/trimmer damage. I thought that installing schedule 80 conduit was the protection. I plan on calling the Inspector to talk about it but just wanted other's opinions. If you had to protect the conduit, what would you do? I thought about sliding a section of 1 1/2" conduit over the existing conduit and let it stick out above ground about 8 inches. Thanks to all who reply.
    I am inclined to agree that over time weed whacker damage will become apparent. Whether the code requires additional protection is something else. Some kind of sleeve is probably easiest, and will cost less than fighting over it.
    Bob

  7. #7
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    I'm inclined to say "humor the inspector."

    Ultimately, it's a judgement call whether an installation is adequately protected. For example, I've seen a lovely EMT installation completely trashed by repeated impacts from pallet jack / stock picker / forklift traffic. In that instance, IMO, it would have been reasonable for the AHJ to require the conduit to be moved, or better protected.

    Your inspector has looked at your instal, and has forseen a particular, very predictable hazard from ordinary maintenance.

    Since the pipe is already in place, it's probably easiest to 'sleeve' the most exposed sides with a bit of strut.

  8. #8
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    I'm sorry but this is worth a fight with said inspector. He needs to know he is not God.

    What is the chance that same installation has the main service lateral just a few feet away in a Schedule 80 PVC and he has nothing to say about that?

    Even RMC can be physically damaged although it takes more abuse to get it done.

    One needs to know what abuse is likely when determining what physical protection is needed - but you never really know what will really happen. What if this install is facing the street and an out of control motorist hits it? There is something likely to damage it if it happens, but is not necessarily that likely to happen, not to mention there is likely damage to more than just this raceway if that happens.

  9. #9
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    Quote Originally Posted by kwired View Post
    One needs to know what abuse is likely when determining what physical protection is needed - but you never really know what will really happen. What if this install is facing the street and an out of control motorist hits it? There is something likely to damage it if it happens, but is not necessarily that likely to happen, not to mention there is likely damage to more than just this raceway if that happens.
    If there is grass planted where the PVC pipe comes up thru the ground, it will almost certainly sustain damage from both lawn mowing and weed whacking. It is not just likely, it is all but certain.

    The question is whether the damage that will be incurred merits additional protection.

    I am never a fan of giving in to the bureaucrats when they are just being power mad control freaks but this seems to me to be a legitimate concern.
    Bob

  10. #10
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    Quote Originally Posted by petersonra View Post
    If there is grass planted where the PVC pipe comes up thru the ground, it will almost certainly sustain damage from both lawn mowing and weed whacking. It is not just likely, it is all but certain.

    The question is whether the damage that will be incurred merits additional protection.

    I am never a fan of giving in to the bureaucrats when they are just being power mad control freaks but this seems to me to be a legitimate concern.
    There are millions of schedule 80 risers out of the ground subject to lawn mowers and weed whackers. I'm willing to bet only a very small percentage are ever damaged and it is likely that somewhat unusual situations have occured when they are damaged.

    Brush blade on the trimmer instead of using typical nylon line would cause damage. It would also cause some damage on RMC although one incident like that would likely just result in a scratch.

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