This pic illustrates the difference between "code" and "reality."
While the NEC has specifications for support, and makes statements such as "suitable for" and "subject to," one cannot apply them without returning to a site and reviewing the original juggement calls that were made.
The tenant of this industrial site had mounted boxes and pipe on the wall. I interpret the shabby condition of both as proof that his installeation did NOT meet the code requirements; a few extra supports and better anchors might have made all the difference here!
It is hard to tell about the EMT, as we do not know just what the prior tenant used the area for. But, it would appear that the boxes, oand pipes, were knocked free somehow. It is also possible that the guy fixing the drywall (another hint that things got rough there) removed any supports, and pried the box loose.
Perhaps this pic is a better example of 'after the instal' damage:
That's the point I'm trying to make: only after the fact do we know for sure if our "design choices" were correct.
[This message has been edited by renosteinke (edited 10-08-2006).]
Re: Subject to damage?#124453 10/08/0608:10 PM10/08/0608:10 PM
Gotta love ECN! I post a pic, trying to (pick the example) either show off a nice bend, or underscore the need to go beyond simply selecting a method, and actually consider actual conditions.... and we're back to examining the instal of a plastic LB.
I believe that I had explainde that the distance away from the wall was made necessary by the 90 degree bend on the opposite side of the wall. Cut the pipe sooner, and the LB would be at a funky angle; bend it tighter, and you've violated required bend radius. Put an LB on the inside, and it will be enclosed in the wall, and inaccessible. In any event, there is less than two inches of air under that LB. Not visible in the pic are either the curb, or the roof overhang, that discourage passing THAT close to the building. Not a work of art? Never said it was. I make no claims as to my work being perfect. Indeed, that my work is so much better than some is a thought that terrifies me some days....
I had a blank check on thet job, as far as design was concerned. PVC was chosen for reasons that had absolutely nothing to do with either price, or ease of install. While I did everything I could to run the pipe in a manner in which it would not be subject to damage, or tripping over, etc... still, it was exposed- so I chose sched 80.
Now, for those not familiar with sewage at all, it may surprise you to know that the stuff itself can be tough on materials. Not to mention that some of the chemicals used are themselves pretty nasty. This is one application for which PVC is a good first choice- even specialty metals often fall short in these applications.
Now, getting back on topic...
I submit that damage is evidence that the original wiring method failed to meet the code requirements for protecting the wires. I don't care that the stuff was crunchedby a tank; what matters when you find this is that you take steps to prevent this damage from happening again. It's not enough to just replace with more of the same.
Looking at the two pics I submitted... it's not a matter of "might be," it's a case of "was." In both cases, the use of ANY exposed wiring method might be questioned, as the stuff got hit. Since the walls themselves look to be in pretty good condition, perhaps, in this case, Romex fished to cut-in boxes would be a "superior" method to running pipe.
Of course, we only know this with hindsight. Isn't that a large part of a 'service' call- looking at what didn't work, and fixing it?
Re: Subject to damage?#124455 10/09/0609:24 PM10/09/0609:24 PM
Back to the first pic of the EMT installation, I see no offsets to bring the EMT snug to the wall and I see no strapping at all. Using the proper anchors and strapping (within 12" of each junction/box fitting), you could construct this exact installation and be able to virtually stand on it without breaking it off the wall, unless the drywall gave out first. Over strapping and extra anchors is perfectly legal, BTW.
(I may be exaxerating with the "standing" on it comment, but you see my point...)
Re: Subject to damage?#124456 10/17/0606:34 PM10/17/0606:34 PM