Code reference for liquid tight coupling

Brent

I thought one of you code guru's might be able to help me with this.

I am looking for a code reference, if any, that specifically states that inserting PV conductors into the end of an EMT or PVC conduit requires a liquid tight gland or similar cord grip fitting. I ran across an installation where the contractor inserted several #10 USE PV panel conductors into the open end of a 1" EMT which was attached under the panel racking.

While this may not be a good practice I can't find a code reference that states that this practice is not allowed.

Thanks,

Brent

westbranch

Re: Code reference for liquid tight coupling

what was at the other end of the PVC? Was he using it to keep things tidy instead of using zip ties?

Brent

Re: Code reference for liquid tight coupling

The other end of the EMT terminated in a jbox where the #10 USE transitioned to #10 THWN-2.

Brent

smatthew

Re: Code reference for liquid tight coupling

Do the wires just run into the bare end of the EMT? I know that's not allowed - the end of the EMT is sharp and can abrade the insulation. There needs to be a insulation bushing at the end. The code reference is NEC 300-15-c

c) Protection. Where cables enter or exit from conduit or tubing that is used to provide cable support or protection against physical damage. A fitting shall be provided on the end(s) of the conduit or tubing to protect the cable from abrasion.

BTW - the NEC is available online at https://law.resource.org/pub/us/code/ibr/nfpa.nec.1999.pdf

Brent

Re: Code reference for liquid tight coupling

Thanks for the reply, There is a bushing at the end of the EMT however it is open and not watertight and is on a rooftop where water can enter the conduit. The other end of the conduit is lower and terminated in a j-box. From what I have seen there is no code reference that says this is not allowed [watertight fitting required].

Brent

smatthew

Re: Code reference for liquid tight coupling

Liquid-tight is a bit of a misnomer. Conduit is there for the protection of the wires and their insulation. You have to assume that conduit outside can and will get water inside of it. For example, buried conduit will always fill up with water (given time), unless you provide positive air pressure like the telephone company does.

Brent

Re: Code reference for liquid tight coupling

Good point. I see allot of installations where we require the contractor to replace buried conductors in conduit because they used THHN instead of THWN-2.

Brent

vtmaps

Re: Code reference for liquid tight coupling

smatthew wrote: »

Conduit is there for the protection of the wires and their insulation. You have to assume that conduit outside can and will get water inside of it. For example, buried conduit will always fill up with water (given time), unless you provide positive air pressure like the telephone company does.

Very true, and poorly understood by many. I know some contractors who learned the hard way... they brought some 2" pvc conduit underground into the basement of a house. The conduit sloped slightly upwards from the house and the water in the conduit would end up dripping down the basement wall.

Also poorly understood by many contractors is that the PVC glue is meant to be used only on the sides of the male.... no glue should be on the female. The reason is that glue on the female is pushed into the conduit and can cause a ridge of glue to form on the inside of the glued joint. When gluing pvc for plumbing, the goal is to be water tight and both male and female should be glued.

--vtMaps