Wire lubricants and wet environment conduit

[NOTSPARKY]

Help me out please , I am an Electronic Engineer and need real world input. Thanks to Hurricane Sally destruction of yard and dock I now have 80 feet of new burried pvc conduit and another 140 feet of pvc conduit on a dock over a brackish bayou, slathered with yellow 77 on THHN THWN-2. Every single lube I find has a caution RE: conductive untill dry. Well, that conduit has not seen dry since it left the store. After this huge expense (rebuild) I was worried about longterm permeation and degradation of insulation on Wire by H20 and lube that is never going to dry. IDEAL product manager sent me a "we have UL listing" and a 1989 UL proposal for testing lubes, no results specific to any brand. In fact no data or results at all. Testing 77 and the Klein "clear" I read 520-850 k ohms for a 1 cm square of the raw gels. Diluted 16 oz in 5 gallons of H20, roughly the calculated volume of 220 feet of 3/4 pvc with a 40 % fill. Got clumps of yellow goop for one dilution no good for test, the clear stuff was about 5 Megs again for a 1cm square sample. Which tells me nothing except that I wasted a bunch of $ and should have asked someone first. So moving on: Anybody have info on deleterious effects if any on insulation, by wire lube ( wax, clear or foam) that cannot dry due to H20 accumulation in conduit ?

 

[infinity]

The inside of the outdoor conduit might never be completely dry. The conductors are rated for wet locations which includes the inside of a buried raceway. I wouldn't worry about it because at some point it may be full of water anyway. Let's see what others have to say.

Welcome to the Forum.

 

[NOTSPARKY]

Thats my point, the conduit will never be dry here in mid October 70 % humidity 89 degree Florida with mean tide level 1 foot below ground level. With old conduit pre Sally, always had water. Sometimes surges reach 6 feet and cover everything. That lube will never dry out, but it sure does stick.

 

[don_resqcapt19]

Why would we care if we have a conductive lube in contact with the cable or conductor insulation? We routinely install cables and conductors in metal conduit which is 1000s of times more conductive than the lube.

 

[NOTSPARKY]

Because If the lube when undried is conductive it contains an electrolyte. In fact if you taste it, it is salty. PVC is not a perfect insulator, if the ions in the electrolyte permeate the insulation then there can be areas of breakdown. We can see under microscope tendrils of copper creeping across alumina substrate in moist conditions. PVC is no where near as good an insulator as alumina, so it is a valid concern . I agree in a metal raceway, the insulation on wire is not (generally) surrounded by water and salt, so no conduction, no problem. Ultimately all insulation breaks down.My question is does the undried conductive wax lube lead to more rapid breakdown of the insulator. If you all say no I will let it be.

 

[don_resqcapt19]

Because If the lube when undried is conductive it contains an electrolyte. In fact if you taste it, it is salty. PVC is not a perfect insulator, if the ions in the electrolyte permeate the insulation then there can be areas of breakdown. We can see under microscope tendrils of copper creeping across alumina substrate in moist conditions. PVC is no where near as good an insulator as alumina, so it is a valid concern . I agree in a metal raceway, the insulation on wire is not (generally) surrounded by water and salt, so no conduction, no problem. Ultimately all insulation breaks down.My question is does the undried conductive wax lube lead to more rapid breakdown of the insulator. If you all say no I will let it be.

Almost all underground conduits are filled with water.

 

[Jon456]

I'd be far more concerned about the conductivity of salt water (or brackish water) in your conduit than of any wire lube. Perhaps you should flush out your conduit with fresh water. After that, I wouldn't worry about it.

 

[tom baker]

I would be more concerned with the THHWN insulation failing, as its PVC and doesn't hold up well.
Have your electrician use XHHW-2 which is a cross linked insulation and is much thicker

 

[LarryFine]

I'm under the impression that the conductive-until-dry warning is in reference to making terminations at the wire ends.

I once received a shock while applying joint compound around a box.

 

[infinity]

The conductive while wet warning is to let you know that it can be dangerous when working in a live panel or live equipment. It will have no effect on the wire in the raceway.

 

[NOTSPARKY]

Thanks all, knew I could get a better read on this from y'all rather than the manufacturer. Jon, I did flush the conduit, hand pumped 15 gallons thru, started comming out clear after 10, now sucking air thru with shop vac. Will take all this advice & stop worrying.

 

[LarryFine]

The conductive while wet warning is to let you know that it can be dangerous when working in a live panel or live equipment. It will have no effect on the wire in the raceway.

That's what I was getting at.

 

[NOTSPARKY]

I did understand your comments Larry & Infinity. Have no intention of messing with live circuit. Once got a 240 V jolt from a hot water kettle in England that someone had miswired. Everything there is DIY, you buy your appliance, toaster whatever then pick out a plug. Have no need to experience that again. But their plugs are nice: big and beefy, molded grip, fuse inside, 1/4 x 3/8 inch solid brass prongs. I will stick to my electronics where 18 AWG is huge, 1 amp is terrifying and 3-24 V predominate.