300.4 For PVC Box?

[W@ttson]

Hello,

Below is a picture of an installation that an electrical inspector called out 300.4 violation. The actual commentary was "300.4 (Box) protection". He said either the box needs to be raised higher or the ground lower.

I am not aware of a minimum height requirement for junction boxes. I am aware of protection of damage for cables and raceway as found in 300.4. It generically says that "Where subject to physical damage, conductors, raceways, and cables shall be protected." It does not mention boxes.

I was thinking maybe he was alluding to the PVC schedule 40. Which would say is susceptible to physical damage, it needs to be schedule 80. This is in a flower bed next to the house. How is it susceptible to physical damage? How does it apply to boxes? why was he making a distinction of the height of the box?

The closest thing I can find is 300.5 which is regards to underground installations. There is part (D) which reads "Direct-buried conductors and cables shall be protected from damage in accordance with 300.5(D)(1) through (D)(4)." In particular (D)(4) reads: "Enclosure or Raceway Damage. Where the enclosure or raceway is subject to physical damage, the conductors shall be installed in electrical metallic tubing, rigid metal conduit, intermediate metal conduit, RTRC-XW, Schedule 80 PVC conduit, or equivalent." Is that in regards to enclosures underground? How can an enclosure be subject to physical damage underground? If it is regarding enclosures that are above ground that have underground conduits feeding into it, how does the conduit type matter in regards to the enclosure damage?

Anyone have any insight?

 

[infinity]

There is no minimum distance a PVC box needs to be above the ground. Even if you used SCH80 conduit the box would be the same.

 

[augie47]

Unfortunately "subject to physical damage " is subjective.
Over the years I have seen a number of PVC boxes damaged by yard equipment.
I would share his concern until I saw the box was protected from damage by some means.

 

[W@ttson]

I would share his concern until I saw the box was protected from damage by some means.

Ok. What would be some protection techniques? If this was in a parking lot, bollards can be placed in front, but this is a flower bed, not going to really fit. If it was in regards to the conduit, it can be made PVC-schedule 80. I do not think the same material change can be made for a box. There is no PVC-schedule 80 box that could be changed to.

How would raising the box or lowering the ground solve anything (just trying to figure out where he was getting at)?

 

[W@ttson]

There is no minimum distance a PVC box needs to be above the ground. Even if you used SCH80 conduit the box would be the same.

Yeah that is where I am getting lost. I can understand if he was calling out the conduit and saying the conduit needed to be schedule 80 but why is he making the comment that the box either has to be raised higher or the ground elevation lowered.

 

[LarryFine]

Tell the inspector that the customer plans to fence in the flower bed.

Or ask what might he think will hit it, since it won't be mowed around.

Can it be shielded from damage and view by a barrier of some type?

 

[infinity]

Unfortunately "subject to physical damage " is subjective.
Over the years I have seen a number of PVC boxes damaged by yard equipment.
I would share his concern until I saw the box was protected from damage by some means.

Augie, is there some specific wording that would allow the inspector to even make this determination regarding subject to physical damage when it comes to PVC boxes?

 

[W@ttson]

Tell the inspector that the customer plans to fence in the flower bed.

Or ask what might he think will hit it, since it won't be mowed around.

Can it be shielded from damage and view by a barrier of some type?

So there used to be a window there (thats why there is a large opening). It will be filled in with concrete once the electrical work is done. An idea would be to treat it kind of like a window and put a metal window well around it. Similar to this:


Leaving the top lip maybe 2 inches proud.

But it will look terrible.

 

[augie47]

So there used to be a window there (thats why there is a large opening). It will be filled in with concrete once the electrical work is done. An idea would be to treat it kind of like a window and put a metal window well around it. Similar to this:
View attachment 2576673

Leaving the top lip maybe 2 inches proud.

But it will look terrible.

won't look so bad once it's removed

 

[Little Bill]

So there used to be a window there (thats why there is a large opening). It will be filled in with concrete once the electrical work is done. An idea would be to treat it kind of like a window and put a metal window well around it. Similar to this:
View attachment 2576673

Leaving the top lip maybe 2 inches proud.

But it will look terrible.

Then the junction box would not be accessible. Or at least without removing the barrier it wouldn't be.

 

[W@ttson]

Then the junction box would not be accessible. Or at least without removing the barrier it wouldn't be.

The one I quickly looked at had a 16" depth.


I would think as along as the wiring is accessible it is compliant and not a violation of 314.29.