NM in Liquidtite

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Re: NM in Liquidtite

What it comes down to is rather simple.There is nothing in any part of article 350 that says that LFNC and the fittings aren`t sufficent to keep the infiltration of moisture or liquids out and that when installed outdoors they need conductors rated for wet locations installed.
PVC as we have agreed when installed under ground/slabbed are required to have wet location conductors installed.But if we mount it outside on a wall,post or whatever the need for wet location conductors goes by the wayside.
Is it possible for moisture/condensation to infiltrate pvc or LFNC in my opinion I would have to say yes.But my opinion or anyone else that feels that way isn`t what we have to heed to.
There has been an old post of mine in which I expressed my disatisfaction with an inspector for tagging a job for nm in a slab.I guess I posted my thoughts wrong,I was not b$%#$ing about getting tagged or having to comply with what was in the code.Granted the conductors should have been UF.My gripe was that this all came out of the blue. Rough ins were at the rate of 30 a week in this particular community where this came to light.The practice even though wrong was allowed for over 300 homes and all of a sudden there were 20 $30.00 red tags in one day.All the inspector had to do was key me up on nextel and the whole thing coud have been remedied really easy.This was one inspector that like the 8 others was told at a meeting to enforce the article.The other 8 gave curtosy shout outs and the situation was taken care of right then and there.I guess one apple spoiled the whole bunch for me.
 
Re: NM in Liquidtite

Originally posted by allenwayne:
What it comes down to is rather simple.There is nothing in any part of article 350 that says that LFNC and the fittings aren`t sufficent to keep the infiltration of moisture or liquids out
No there is not a section like that or one for PVC or GRC etc.

But if you run them any of underground they are called a wet location apparently those methods all leak. :D
 
Re: NM in Liquidtite

Nonmetallic-Sheathed Cables
UL 719
1 Scope
1.1 These requirements cover nonmetallic-sheathed cables containing 2 - 4 thermoplastic-insulated circuit conductors with or without a grounding conductor in the constructions indicated in Table 1.1. These cables are intended for use in accordance with Article 334 and other applicable parts of the National Electrical Code (NEC) , ANSI/NFPA 70. Type NMC cable is for use in dry, moist, damp, and corrosive locations, and Type NM cable is for use in normally dry locations. Both types carry the suffix letter "-B" to designate the use of conductors with 90?C insulation.
1.2 A cable to which the designation "-LS" (signifying "limited smoke") is applied as a type-letter suffix complies with the test criteria for smoke release and for cable damage height stated in the Standard for Vertical-Tray Fire-Propagation and Smoke-Release Test for Electrical and Optical-Fiber Cables,UL 1685.Table 1.1 Cables covered in this standard

Well I don?t need a formal education to know that when it is raining that outside is not a normally dry location.

I have a few chickens running around the yard and every once in a while I watch them. Some of my observations about these chickens is they have a very small head which couldn?t hold a brain much bigger than a BB. Another one is that when it starts raining they run for shelter, must be because the rain is about as wet as water.

Yes I did say that rain is ?about? as wet as water. I can prove that it is not as wet as water. When it is raining just a little and I am out side, the top of my head and shoulders get wet, but when I jump in the river I get wet all over real fast. Therefore the rain is about as wet as water.

This may be the thinking of those who believe that the outside is not a wet location?
:)
 
Re: NM in Liquidtite

There is no debate in regards to when conduit is underground as we have spoken about wet rated conductors must be used.Probably because as electricians we try to keep water out but succeed in doing it 50% of the time.
Very rarely have I seen an electrician with a can of anything besides pvc glue.I am sure there are some here that actually take the time to deburr clean,prime and glue whatever pipe they install underground.But the number of glue it and move on guys out number them 2 ,3 ,4 maybe 5 to 1.
 
Re: NM in Liquidtite

Very rarely have I seen an electrician with a can of anything besides pvc glue
I don't think that using just glue will make the conduit any less water tight. It just may not stay together as well.
 
Re: NM in Liquidtite

allen,
Very rarely have I seen an electrician with a can of anything besides pvc glue.I am sure there are some here that actually take the time to deburr clean,prime and glue whatever pipe they install underground ...
I have never seen PVC conduit installation instructions that recommend or require the use of a primer when joining PVC conduit and fittings.
Don
 
Re: NM in Liquidtite

PVC electrical conduit is a softer plastic than PVC water pipe. Water pipe requires primer to soften the plastic so the glue will bite and you will have a water proof and pressure proof connection.
PVC electrical conduit fittings are not water tight. PVC water fittings are tapered in the bell and thats why the pipe has to be held in or it will be pushed back out until the glue sets.
And the instructions for PVC electrical conduit don't require primer.
 
Re: NM in Liquidtite

It seems that this debate is based on the premise that the interior of a conduit system is a separate environment from the exterior of the conduit. I beleive this is an incorrect premise.

I also believe that, if the conduit is installed in a wet location, so are the conductors within. The conductors are outdoors, whether encased or not. Conduit is physical protection.

Now, having said that, when an inspector allowed me to strip the sheath from a length of NM as it entered some FNMC that penetrated a roof through a pitch pocket, I didn't complain.
 
Re: NM in Liquidtite

Originally posted by Larry Fine
It seems that this debate is based on the premise that the interior of a conduit system is a separate environment from the exterior of the conduit. I beleive this is an incorrect premise.
I have a hard time understanding this debate. Think of it like this:

The phone rings and the party ask for Mike. The wife says, ?he is outside could he call you back??

I was sitting in the truck talking with my helper when this call came. It was pouring down rain and I was waiting for a break before coming in the house.

Where was I? I was in the dry so to speak. The windows were getting foggy and hard to see out of so I would presume that I was in a damp place.
The wife was correct when she said that I was outside as the truck was outside.

The conductors from the disconnect to the AC unit are outside. The fact that they are enclosed in a raceway does not change that fact.

Larry has said it all with his statement,
? I also believe that, if the conduit is installed in a wet location, so are the conductors within. The conductors are outdoors, whether encased or not.?
You go Larry Fine
:cool:

[ October 24, 2005, 03:29 PM: Message edited by: jwelectric ]
 
Re: NM in Liquidtite

Originally posted by jwelectric:
I was sitting in the truck talking with my helper when this call came. The windows were getting foggy and hard to see out of so I would presume that I was in a damp place.
Looks like someone has gone from writing code arguments to romance novels. :D
:D :p

Who wants to know how this one ends?

[ October 24, 2005, 09:47 PM: Message edited by: electricmanscott ]
 
Re: NM in Liquidtite

if waiting in the truck was "outsifde", why not just walk in the house, as there was no difference between in and out of the truck. the example is perfect as an example as it points out the code as well... wiring and installations "inside" a truck cab parked "outside" and other objects and devices within this truck cab environment are considered damp at best. The truck cab environment is considered "inside" although it is "outside" of the house.

paul :cool:
 
Re: NM in Liquidtite

Now I ain't to brite so you?ll be needing to help me just a tad.
Originally posted by apuling The truck cab environment is considered "inside" although it is "outside" of the house.
How do you have something on the inside when it is on the outside?

That sounds like me asking you are you over there? You say, ?No, I am right here.?
I say, ?You can?t be because I am right here. Now if I am right here and you say that you are not right over there, then you got to be somewhere else, don?t you??

First the wire, devices and equipment in my truck won?t be there but for a short period of time. The conductors installed in a raceway exposed to the weather are a different story. Not only are the going to be subject to the eye of the code enforcement official and the rules of the NEC they are going to be in place for an extended length of time.

Answer these,
How many AC units come with a ? inch KO for the supply conductors? Most.
Is ? inch flex being installed? Not often.
Does as set of washers give a water tight seal? No
Is outside a wet location? Yes
So do you think that a conductor listed for a wet location should be installed outside? Yes and here is the reason.

ARTICLE 225 Outside Branch Circuits and Feeders
225.1 Scope.
This article covers requirements for outside branch circuits and feeders run on or between buildings, structures, or poles on the premises; and electric equipment and wiring for the supply of utilization equipment that is located on or attached to the outside of buildings, structures, or poles.
225.4 Conductor Covering.
Where within 3.0 m (10 ft) of any building or structure other than supporting poles or towers, open individual (aerial) overhead conductors shall be insulated or covered. Conductors in cables or raceways, except Type MI cable, shall be of the rubber-covered type or thermoplastic type and, in wet locations, shall comply with 310.8.

ARTICLE 310 Conductors for General Wiring
310.1 Scope.
This article covers general requirements for conductors and their type designations, insulations, markings, mechanical strengths, ampacity ratings, and uses.
310.8
(C) Wet Locations. Insulated conductors and cables used in wet locations shall be
(1) Moisture-impervious metal-sheathed;
(2) Types MTW, RHW, RHW-2, TW, THW, THW-2, THHW, THHW-2, THWN, THWN-2, XHHW, XHHW-2, ZW; or
(3) Of a type listed for use in wet locations.
:)
 
Re: NM in Liquidtite

it's still quite simple, the inside of above ground pvc is by code not "WET". If you want to jump up and down on the code book, don't dismiss it when it doesn't say what you want it to. The irony of citing code to disagree with the code is lost in this forum.

paul
 
Re: NM in Liquidtite

Originally posted by apauling:
it's still quite simple, the inside of above ground pvc is by code not "WET".
Glad you came by to straighten us all out. :D

By the way, the inside of above ground pvc is by code not "DRY" either. :D

[ October 25, 2005, 05:19 AM: Message edited by: iwire ]
 
Re: NM in Liquidtite

Originally posted by apauling:
at least we agree that it is not wet :D
:D

No, we agree the code does not specify either way.

The code also does not tell me rain is wet but I take that as a given. :p

[ October 25, 2005, 05:53 AM: Message edited by: iwire ]
 
Re: NM in Liquidtite

Originally posted by apauling:
it's still quite simple, the inside of above ground pvc is by code not "WET".
paul
Especially after the excessive moisture is drained from the raceway as required by 225.22. :D

Roger
 
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