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#124646 - 11/18/06 05:46 PM RNC VS. RMC
electure Offline

Registered: 12/24/00
Posts: 4259
Loc: Fullerton, CA USA
From Scameron81

This is a prime example of why I don't think that you should be allowed to use schedule 80 for service risers. It just doesn't hold up like steel does. These are unprotected 700 Kcmil feeding straight from the transformer. This is along a very busy section of sidewalk. IMO you can't beat 10mil wrapped RMC for a riser

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#124647 - 11/18/06 07:31 PM Re: RNC VS. RMC
mahlere Offline
Registered: 11/17/05
Posts: 507
Loc: New Jersey
unless you are anywhere near an ocean and the RMC rusts out in a few years....
#124648 - 11/18/06 08:19 PM Re: RNC VS. RMC
Ann Brush Offline
Registered: 12/27/05
Posts: 152
Loc: Ohia
Or anywhere near where they salt roads in the winter - that stuff EATS just about anything - especially my car.
#124649 - 11/18/06 09:02 PM Re: RNC VS. RMC
Lostazhell Offline
Registered: 02/21/04
Posts: 1428
Loc: Bakersfield, CA (Originally Or...
the 10 mil tape mentioned above is designed to block out the elements when used properly... You'd be just as good using a stick of OCAL conduit (PVC coated RMC) Alot cleaner looking than the 10 mil wrapup
#124650 - 11/19/06 06:16 AM Re: RNC VS. RMC
john p Offline
Registered: 11/02/06
Posts: 32
Loc: Bemidji,MN.USA
Just think if this was steel things would of moved and blew up, Now you can shut down and repair this. Etheir way pvc or steel you cant protect every thing. Maybe This should be in a diffent location, If its subject to physical damadge.
#124651 - 11/19/06 07:55 AM Re: RNC VS. RMC
Rewired Offline
Registered: 01/01/06
Posts: 558
Loc: Hamilton, Ontario, Canada
Actually I have been noticing a lot of older services now that were done in RNC that are coming apart or actually shattering. My parents place was built in the 60's and the service was done in rigid ALUMINUM, well everthing except the galvo mast and the cast LB at the bottom, but in general the service is in better shape than some of the one's I have seen where the PVC is all shattered or the fittings are coming apart and the service conductors are now exposed.

#124652 - 11/19/06 02:10 PM Re: RNC VS. RMC
renosteinke Offline
Cat Servant
Registered: 01/22/05
Posts: 5316
Loc: Blue Collar Country
There is a pole near me that has sundry RNC covered lines at ground level. PoCo, Phone, whatever.

The pole is situated that it would be difficult for anything to strike the plastic pipe. Yet, over the years, I have watched the pipes crack and shatter, losing a little more each day. Recently, most of these pipes were replaced with new PVC.

I think the stuff just loses its' plasticisers over time. Perhaps ozone and exhaust fumes just degrade the stuff; I don't know.
#124653 - 11/19/06 03:05 PM Re: RNC VS. RMC
BigJohn Offline
Registered: 03/06/04
Posts: 391
Loc: Boston, MA
Given that PVC deteriorates in UV and o-zone, weakens in the cold, is generally much more conspicuous than EMT, and is very often improperly installed (no expansion fittings, too few/wrong type of straps), these are reasons I hate seeing PVC above ground.

PVC does have it's place (costal/industrial enviroments with corrosive atmospheres). But it still requires some care to install. There's nothing I hate more than a perfectly straight run of pipe that would've been nice and pretty in EMT or rigid, but instead was run improperly in PVC and ends up being so wavy I need Dramamine just to look at it.


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