Building specifications no wire smaller than number 10 CHW

Status
Not open for further replies.

cadpoint

Senior Member
Location
Durham, NC
I've worked jobs where about all the same specs. state to run the first one hundred feet in #10 stranded.
The last one that I was on required out to one hundred & fifty.
I think that someone forget to finish the editing of article (what's it up to) 16 !!!
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
There's a big argument over here on this job over the specs.
This large project
there is no wire allowed smaller than number 10
No stranded. Has to be solid. (no wire smaller than number 8 can be stranded. )
Also no pipe smaller than 3/4" emt
No flex below 8 feet.
Rigid pipe only were accessible to the public have
I did some cherry picking:
anyone who specifies solid wire is an idiot. ...
Yes
I had one electrician tell me he didn't like stranded in panels because he couldn't bend the wires to lay them in real neatly. Tell me again, "Why is this on my list of concerns?"


IME a lot of places ban conduit under 3/4. I have no idea why but it is pretty common. ...
20 years ago I was asking and the answer I got was: "1/2 rsc beaks at the threads much easier than 3/4 rsc. These outfits tended to use rsc in process areas, and EMT in non-process (office areas). Now most of these have gone to MC-HL. That gets rid of a truckload of issues with ground frost heaving and UG conduit/conductor failures.

in control applications with pilot duty devices, #18 & #16 stranded MTW is very common.
i've never had a wire of ANY guage fail when being pulled, in 35 years.
I've had plenty fail underground in rsc - but not when pulling. The conduits eventually fill with water and when it freezes, the freeeze plugs stretch the wire until it fails. Anecdotal information:
Happens more to solid than to stranded. Happens rarely to conductors #8 and larger.

I guess if one knew that all circuits were loaded to the max and were >100', then a #10 spec would be fine. But what about the control condctors - #10 solid in a control cabinet or MCC.
:sick:

ice
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
minor editing. Not meant to change intent:
... Adjust your attitude and those around you to what is being paid for.

... When others start making pronouncements like "This isn't right and a waste of money", I'm thinking burnout case. Someone that is having mental difficulties coping and insulting my customer and there employment.

When someone asks for something like this I say three words "OK, sounds good", and nod with a smile. I give the benefit of the doubt that they know what they are talking about and know what they are buying from me and I am grateful for the work.

When I am being paid to install, this is exactly the attitude I strive for. Expecially the, "nod with a smile". Followed by, "Yeah, we can do that."

If its not illegal, and not unsafe, then that's what I get paid to do - get it installed, make it work per spec.

Now, if it is me doing the specifying, then I have the lattitude to make it my way - and I do. I take special pleasure in screwing it up my way.

ice
 

Fulthrotl

~Autocorrect is My Worst Enema.~
I did some cherry picking:
Yes
I had one electrician tell me he didn't like stranded in panels because he couldn't bend the wires to lay them in real neatly. Tell me again, "Why is this on my list of concerns?"



20 years ago I was asking and the answer I got was: "1/2 rsc beaks at the threads much easier than 3/4 rsc. These outfits tended to use rsc in process areas, and EMT in non-process (office areas). Now most of these have gone to MC-HL. That gets rid of a truckload of issues with ground frost heaving and UG conduit/conductor failures.


I've had plenty fail underground in rsc - but not when pulling. The conduits eventually fill with water and when it freezes, the freeeze plugs stretch the wire until it fails. Anecdotal information:
Happens more to solid than to stranded. Happens rarely to conductors #8 and larger.

I guess if one knew that all circuits were loaded to the max and were >100', then a #10 spec would be fine. But what about the control condctors - #10 solid in a control cabinet or MCC.
:sick:

ice

i've seldom ran control wires in underground conduits, so the freezing
thing is news to me. i've also stayed away from areas where my wires
and my ass might freeze.

don't even *type* #10 solid control wires, someone might google search
it, and this sort of idea is not one we want to spread, is it?

and as a rule, i don't generally use anything smaller than #14 thhn stranded
for controls, for the obvious reasons, but it does get used, a lot.

as for panels looking good with stranded, they look far better than
they do with solid, if you know how to lace them up properly.

i've got some photos of old control panels still in use at LADWP,
where their is a 2" conduit, with #12 tinned braided control wire
from 90 years ago in it, and the stuff comes out of the conduit in
a perfectly square array, say 8 x 10 wires, and they all are perfectly
straight, and concentrically bent, and peel off the bundle at the
terminals they go to, without crossing. it's flat freaking amazing.
i have no idea how long it took to do it. it's mind boggling, however...
int looks like it was done by an Instrumentation pipe fitter....

and the control panel is glossy black, and looks like corian, with the
meters all mortised in, looks like it was done with chisels, perfectly
inletted.....

of course, the panel is 1/2" 100% asbestos, polished. no drilling or cutting
allowed... at least not anymore....
 
Last edited:

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I have only ran across a few wires that failed while being pulled. There were all #14 and the EC had already left the site. It is one of the reasons I almost always spec extra wires be pulled. I do not want to be out there and need to have a wire replaced in a conduit after the EC is gone. It is pretty easy to just switch to a spare. Having to get the EC to come back and replace the wire is very painful.

The cost used to be almost negligible for spare wires. It is not as negligible as it once was.

In fairness, I have never had to use a spare to replace one that failed, but I have on occasion used them for something that gets added after the fact.
 

renosteinke

Senior Member
Location
NE Arkansas
Asking around the steel mill ...

Their specs are similar.

No idea what "CHW" is. THW is history. THHW/THWN is the usual wire type.

They like pipe 3/4 and larger, because they like the extra space in the LB's and Tees ... and because the stuff is often climbed upon or subjected to some fierce abuse. Remember, they often make connections in conduit bodies for the various sensors and limit switches.

They like stranded wire for fishing through their control panels, etc. They're "Stak-On" happy, and it can be a real PITA to crimp a fork onto a solid wire.

Voltage drop can be a real issue. 100 ft? Not hard to do, when your building is 1/4 mile long and each piece of product is 60 ft. long.
 

PEDRO ESCOVILLA

Senior Member
Location
south texas
with respect to making up the a panel and using stranded wire, sticky backs and cable ties, properly placed will make a nice job look great. don't use 'em and a nice job can look like a rats nest.
 

Stevareno

Senior Member
Location
Dallas, TX
I have only ran across a few wires that failed while being pulled. There were all #14 and the EC had already left the site. It is one of the reasons I almost always spec extra wires be pulled. I do not want to be out there and need to have a wire replaced in a conduit after the EC is gone.

Wait. You don't make the EC warranty their work? After they leave the site, they are "scot free" if anything goes wrong? :?

with respect to making up the a panel and using stranded wire, sticky backs and cable ties, properly placed will make a nice job look great. don't use 'em and a nice job can look like a rats nest.

Making up a panel with stranded is an art. I like the challenge. If you're really good, you can do it without using cable ties during the process. Route/land all wires and then make everything neat at the end with cable ties. :cool:
 
Status
Not open for further replies.
Top