Ok To Bury Temporary Cord?

Status
Not open for further replies.
F

FbksCoE

Member
I'm running temporary power to a building under construction with hard service cord. The cord needs to cross a temporary road next to the building subject to heavy traffic - cranes, trucks, forklifts.

Are there any prohibitions, NEC or otherwise, from burying the cord under a foot of gravel where it crosses the road? Will doing so protect the cord from phyiscal damage or would the gravel itself pose a threat of damage?
 
Ouch. I think the gravel itself would pose a bit of a threat of damage.

For temporary work like that, I'd use RMC under 24".

Wecome to the forum.
 
FbksCoE said:
I'm running temporary power to a building under construction with hard service cord. The cord needs to cross a temporary road next to the building subject to heavy traffic - cranes, trucks, forklifts.

Are there any prohibitions, NEC or otherwise, from burying the cord under a foot of gravel where it crosses the road? Will doing so protect the cord from phyiscal damage or would the gravel itself pose a threat of damage?
Click to expand...

The last road crossing I did I took 1-1/4" PVC and sleeved the crossing then cut asphalt just enough to fit the pipe. I went down 1'. Back fill with sand if you have rocks. Perhaps use sch 80 if you are concerned.
 
None of the flexible cords or cables in Table 400.4 are listed for direct bury under the use column.

Also, take a look at 400.7 and 400.8 for uses permitted and not permitted.

If it is protedted from physical damage and not in direct contact with earth, it may not be a violation.

Maybe some others will give their take on it.
 
I beleive temperature is a concern, not the direct contact with earth. If I recall correctly it wouldn't matter if it's in raceway, raceways, or direct bury. If it's below grade, it's underground.

You could run temporary wire up a temporary pole over your temporary road.
 
FbksCoE said:
I'm running temporary power to a building under construction with hard service cord. The cord needs to cross a temporary road next to the building subject to heavy traffic - cranes, trucks, forklifts.

Are there any prohibitions, NEC or otherwise, from burying the cord under a foot of gravel where it crosses the road? Will doing so protect the cord from phyiscal damage or would the gravel itself pose a threat of damage?
Click to expand...

Hard service only indicates that the cable is designed to be rolled up and unrolled frequently.

I have looked at general cables site and have not found one of their cables that is advertised as suitable for wet locations (raceway underground) or direct burial.

I (for one) would not accept this installation unless the installer could produce literature indicating the cable is listed for the use.

Neither 590, nor article 400 would lead one to believe that this is acceptabel either.
 
2008 NEC
400.3 Suitability. Flexible cords and cables and their associated
fittings shall be suitable for the conditions of use
and location.
Click to expand...

According to the Wire and Cable Marking Guide in the 2008 UL White Book, as well as Table 400.4 in the NEC, there doesn't appear to be any flexible cords that are listed for direct burial.

2008 NEC
ARTICLE 590 Temporary Installations
590.2 All Wiring Installations.
(A) Other Articles. Except as specifically modified in this
article, all other requirements of this Code for permanent
wiring shall apply to temporary wiring installations.
Click to expand...

It is always illegal to bury cord, even in a raceway.
 
Last edited:
FbksCoE said:
I'm running temporary power to a building under construction with hard service cord. The cord needs to cross a temporary road next to the building subject to heavy traffic - cranes, trucks, forklifts.

Are there any prohibitions, NEC or otherwise, from burying the cord under a foot of gravel where it crosses the road? Will doing so protect the cord from phyiscal damage or would the gravel itself pose a threat of damage?
Click to expand...

some reason you can't use UF?
 
FbksCoE said:
I'm running temporary power to a building under construction with hard service cord. The cord needs to cross a temporary road next to the building subject to heavy traffic - cranes, trucks, forklifts.

Are there any prohibitions, NEC or otherwise, from burying the cord under a foot of gravel where it crosses the road? Will doing so protect the cord from phyiscal damage or would the gravel itself pose a threat of damage?
Click to expand...

I hope your not directing the EC or his men to do this.
 
Get some tray cable...most is listed for direct burial applications and is probably cheaper than cord. You would have to comply with 300.5.
 
A common use for multiconductor tray cable is for submersible sewage pump controls on the floats.
Why is TC direct bury rated? It may be thats a bonus of the cable insulation type.
 
LarryFine said:
Of course! For those outdoor cable-tray installations. :cool:

I noticed traffic-signal use. I like those kinds of cables.
Click to expand...

i guess what i was trying to say, is TC has a bunch of other uses besides in trays. Its sunlight resistant so you can use it aerial with a messenger wire for example.
 
2008 NEC
ARTICLE 590 Temporary Installations
590.2 All Wiring Installations.
(A) Other Articles. Except as specifically modified in this
article, all other requirements of this Code for permanent
wiring shall apply to temporary wiring installations.

As Dan posted this earlier in the thread, I think this is the most important reason why one cannot bury cable as proposed by the OP.
 
Status
Not open for further replies.
Top