[RE-wrenches] Exterior conduit in corrosive environments

[R Ray Walters]

PVC doesn't look as professional, especially when it starts browning in the sun after a few years.
We still use it a lot though, as its durable, nonconductive, and easy to use.
5 things we do to make PVC better:
No long exposed runs (to avoid expansion problems)
Use Sch 80 coming out of the ground, and other locations exposed to physical damage
Have the owner paint the conduit to match after. (solves the UV browning problem, and the aesthetic issue)
Use stainless mounting hardware (as the plastic clamps are a joke, and snap after a couple of years)
Don't use PVC under 3/4" Diam.  (1/2" PVC is also laughable, we often oversize to 1", just because it doesn't behave like spaghetti)

I've run over 1" SCH 40 PVC with a 4 ton truck, and just ovaled it slightly, the wires were unmarked.
I've seen too many EMT compression fittings come loose, and cut into the exposed wires. I think the new generation of comp fittings are better though ( hopefully)

R. Walters
ray at solarray.com
Solar Engineer




On May 19, 2010, at 4:09 PM, Andrew Truitt wrote:

> 
> 
> William,
> 
> We are also in the market for a good non-corrosive solution for coastal locations.  We just finished a job with aluminum EMT with threaded couplings and it worked fine, but that job happened to have a simple DC conduit run.  I can imagine things getting a lot more difficult when trying to thread bent conduit into a complex wall-mounted run.  Are there really no rain-tight aluminum compression fittings in existence?
> 
> My electrician advocates using PVC in these environments.  My arguments against that are 1) aesthetics and 2) durability of the joints considering temperature degradation of the glue and thermal cycling of the material.  What do you [all] think?
> 
> 
> 
> Andrew Truitt
> Standard Solar Inc.
> 
> 
> p.s. - I sent something out on Expansion Fittings yesterday but it never showed up in my inbox, though I did get one response to it that was addressed just to me.  Did anyone else get that one?  Very strange...
> 
> 
> 
> 
> 
> 
> On Mon, May 3, 2010 at 1:18 PM, William Miller <william at millersolar.com> wrote:
> Friends:
> 
> We are just completing a non-penetrating roof mount in a beach environment.  We chose aluminum rigid for our PV feeders.  Cost about 1.30 per foot, easy to work with (for real electricians -- you need to have a threader and rigid experience).  I recommend it.
> 
> William Miller
> 
> Please note new e-mail address and domain:
> 
> William Miller 
> Miller Solar
> Voice :805-438-5600
> email: william at millersolar.com
> http://millersolar.com
> License No. C-10-773985
> 
> 
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