Cable or wire in pier side trough containing water pipe

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smfloyd

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There is a concrete trench on the deck of a water side pier that contains a 4 inch diameter water pipe. The trench is about 2 feet wide by 18 inches deep. It is desired to run 480 VAC 3 phase in this same trench. We want to run either G-GC CABLE or XHHW-2 wire. Question, do either of these need to be in their own conduit/raceway?
My concern is NEC 300.8
 
The cable spec states "Not for use as permanent building wiring". It seems like a very robust wiring method, for "flexible, portable, and extra-hard usage applications"
I would use PVC conduit with expansion couplings and XHHW-2 conductor
 
Thanks Tom, the electrician/contractor just wants to bundle the 480 VAC 3 phase XHHW-2 and lay it in the trench. I think conduit is required/good idea. I’m trying to find a NEC code requirement for the conduit.
 
smfloyd said:
Thanks Tom, the electrician/contractor just wants to bundle the 480 VAC 3 phase XHHW-2 and lay it in the trench. I think conduit is required/good idea. I’m trying to find a NEC code requirement for the conduit.
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Can't make sense to lay XHHW-2 in a trench with a water pipe. What about the poor plumber who comes along in 5 years? Makes no sense.
 
smfloyd said:
Thanks Tom, the electrician/contractor just wants to bundle the 480 VAC 3 phase XHHW-2 and lay it in the trench. I think conduit is required/good idea. I’m trying to find a NEC code requirement for the conduit.
Click to expand...
No conduit needEd if the trench is a chapter 3 wiring method.
just ask your electrician for the concrete trench article number
 
smfloyd said:
the electrician/contractor just wants to bundle the 480 VAC 3 phase XHHW-2 and lay it in the trench. I think conduit is required/good idea. I’m trying to find a NEC code requirement for the conduit.
Click to expand...
As others have pointed out 300.3 and I'll add 300.2:
Code: 
300.2 Limitations.
(A) Voltage. Wiring methods specified in Chapter 3 shall be
used for 1000 volts, nominal, or less where not specifically limited in some section of Chapter 3.

Code: 
300.3 Conductors.
(A) Single Conductors. Single conductors specified in
Table 310.104(A) shall only be installed where part of a recognized wiring method of Chapter 3.

There is only one exception:
Exception: Individual conductors shall be permitted where
installed as separate overhead conductors in accordance
with 225.6.
 
Since the application under discussion is on a pier, isn't there something in Chapter 5 that bears on this question? Maybe that would allow the G cable laid in the trench?

Edit: looks like 555.13 would be applicable, and cable would only be a possibility if the trench is on the underside of the pier or "flexibility is necessary as on piers composed of floating sections"

Cheers, Wayne
 
smfloyd said:
There is a concrete trench on the deck of a water side pier that contains a 4 inch diameter water pipe. The trench is about 2 feet wide by 18 inches deep. It is desired to run 480 VAC 3 phase in this same trench. We want to run either G-GC CABLE or XHHW-2 wire. Question, do either of these need to be in their own conduit/raceway?
My concern is NEC 300.8
Click to expand...
Concrete trench on a deck of a pier? Or is this a jetty? How are you getting a "concrete trench" into a pier? What sort of covering would be on this "concrete trench"?
XHHW-2 is not listed to be installed "unprotected", it might contain additional listing for direct burial and thus protection by burial. But a concrete trench is not direct buried, but in this suggested application "concrete trench" is being used as a raceway. If this "trench" is going to contain "foreign" (non electrical) installation, it would seem you can't also count it as a raceway thus any electrical installation would require it's own raceway within the "trench". Anybody considering installing plumbing through your electrical enclosures or raceways?
 
IMO, Since it's a pier, Art 555 will allow the G Cable without conduit. Installations such as that have been approved locally (doesn;t mean they are correct but our AHJs approved)
 
augie47 said:
IMO, Since it's a pier, Art 555 will allow the G Cable without conduit.
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555.13(A)(2) allows certain "portable power cables" in two cases:

(1) As permanent wiring on the underside of piers (floating or fixed)
(2) Where flexibility is necessary as on piers composed of floating sections

I don't see how a trench in the deck of a pier meets (1)? I guess you could interpret "underside" to mean "anywhere below the walking surface".

Cheers, Wayne
 
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