MV conduit run crossing help.

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69gp

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MA
MV Conduit crossing.jpg

First of all I am filling in for my dad while he is away. Looking for clarification on how you would deal with this. Have a site where a 4" EMT-13,200 MV conduit is run over the surface of a landfill cap. There are several crossings along this run as it is about a mile long. At the crossings the EMT has a 6" PVC drain pipe sleeved over it. This was then covered with about 8" of processed gravel and than about 4" of loam. This is about a year old. the crossings are supposed to be for light duty equipment only. They have been using what appears to be about a 50 hp 4 wheel drive tractor with a brush hog type mower on the rear. It appears that the mower is cutting the crossing down as it goes over the crossing. Estimate that the equipment is around 4500 to 5000 pounds. in some locations there is only 2 to 3" of gravel over the PVC drain pipe.

Since this is not technically buried in a trench and not subject to commercial traffic how would you determine what the proper coverage would be for this crossing. My feeling would be to ramp up and over the conduit with a minimum of 4" of concrete.

Any help would be appreciated. gotta take care of dad while he is away.

nic
 

iwire

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Location
Massachusetts
Odd situation

In my opinion once the dirt was put over it that section would be subject to 300.5 and it's depth requirement.
 

GoldDigger

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I would worry just as much about whether they are in fact mowing the whole surface and therefore running the mower over all parts of the surface run of EMT, not just the official crossings.
A commercial riding mower has fat tires and a pretty low load factor. A tractor with a brush hog has a much higher pressure tire footprint.

From the tire tracks in the picture, it looks more like it is just crossing. But is the unpowered brush hog deck doing the scraping or are they traveling with the PTO engaged? The tractor itself should have enough clearance to avoid any problems.
Looks like maybe a lazy operator.
 

69gp

Senior Member
Location
MA
I would worry just as much about whether they are in fact mowing the whole surface and therefore running the mower over all parts of the surface run of EMT, not just the official crossings.
A commercial riding mower has fat tires and a pretty low load factor. A tractor with a brush hog has a much higher pressure tire footprint.

From the tire tracks in the picture, it looks more like it is just crossing. But is the unpowered brush hog deck doing the scraping or are they traveling with the PTO engaged? The tractor itself should have enough clearance to avoid any problems.
Looks like maybe a lazy operator.

I think that someone must have driven across the crossing with a vehicle as those tire tracks are a lot thinner than the tractor. Don't know if they are disengaging the PTO to the mower when they cross over.
 

69gp

Senior Member
Location
MA
Odd situation

In my opinion once the dirt was put over it that section would be subject to 300.5 and it's depth requirement.


i just looked under 300.50 for minimum coverage for conductors over 600 volts and they do not list EMT for burial depth. does that mean i need to use column 6?

thanks

nic
 

GoldDigger

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Location
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Retired PV System Designer

69gp

Senior Member
Location
MA
Can't help with the code, but can help with the wording: it is a bushhog not brush hog. :)

here in MA a Bush hog is what I hunt when I go to Africa. I mow the back 40 with a brush hog. Guess its all related to wear you live. Got to ask do you drink Soda, PoP or Tonic? because after mowing the back 40 I have a cold bear from the fridge
 
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