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Posted By: Trumpy US Conduit Sizes? - 12/10/02 06:26 AM
What sizes of Electrical Conduit are common in the US?.
For PVC and other types.
What is the largest size available?.
Your Help please-
Posted By: CTwireman Re: US Conduit Sizes? - 12/10/02 02:16 PM
It varies by application, but 3/4" and 1" are the most common for branch circuits in many commercial and industrial situations. For feeders and the like, it can vary from 1.25" all the way up to 6", depending on the size of the wires, of course.

The available sizes of conduit are 1/2", 3/4", 1", 1.25", 1.5", 2", 2.5", 3", 3.5", 4", 5" and 6".

PVC is available in sizes up to 6". Metal conduit, such as EMT and Ridgid, is available in these sizes as well, although I am not sure if it is available in 5" and 6".



[This message has been edited by CTwireman (edited 12-10-2002).]
Posted By: rmiell Re: US Conduit Sizes? - 12/10/02 06:14 PM
CT, I suprised that you still use the trade size instead of the "Metric Designator" used in the 2002 code book.
16 = 1/2", 21 = 3/4", 27 = 1", 35 = 1 1/4", 41 = 1 1/2", 53 = 2", 63 = 2 1/2", 78 = 3", 103 = 4", 129 = 5", and 155 for 6".

"Hey Jimmy, as your 1st job as an electrician's helper, go to the truck and get 30.48 meters of #16 conduit!"

Is anybody really using meteric measurements?

Rick
Posted By: CTwireman Re: US Conduit Sizes? - 12/10/02 08:29 PM
Hey Rick, you're right. I haven't purchased the '02 yet. My state is still on the '99, so that explains why I used the "old" designations.

<drives to supply house to get new code book>

I forgot the Code is metric now. My bad.

Peter

PS. I haven't seen anyone using metric measurements. I don't even see metric tape measures for sale anywhere.

I guess wire is next. "Hey, go get a 151 meter spool of 2.O mm THHN." Yuck!!
Posted By: pauluk Re: US Conduit Sizes? - 12/10/02 08:40 PM
I see both metric and English/US Customary units in the '02 NEC.

As the conversions are rounded rather than exact (e.g. 900mm is not exactly 3 ft.) I assumed that it was intended that the metric units be employed in those countries which are traditionally use metric measurements(this being the first "international" NEC) and that the English units are for the U.S.A.

Peter,

Hard to find a tape measure in this country which doesn't include millimeters. I had to order one from Arizona last time I needed a replacement!

Take a look here .




[This message has been edited by pauluk (edited 12-10-2002).]
Posted By: CTwireman Re: US Conduit Sizes? - 12/10/02 08:44 PM
Paul, thanks for the correction (once again), I didn't mean to imply the code was all metric, I meant Metric/English, heavy emphasis on metric, although I suspect most here will continue to use the English units primarily. Please correct me if I am wrong.

Peter

[This message has been edited by CTwireman (edited 12-10-2002).]
Posted By: pauluk Re: US Conduit Sizes? - 12/10/02 08:45 PM
Sorry Peter -- I was editing my message as you posted. Should work now!
Posted By: Nick Re: US Conduit Sizes? - 12/11/02 12:52 AM
EMT and IMC are only available up to 4" -eh ehm- #103 trade size. PVC, and GRC are available up to 6" (#155)

[This message has been edited by Nick (edited 12-10-2002).]
Posted By: Nick Re: US Conduit Sizes? - 12/11/02 01:02 AM
I did have to run 8" once. It was for pulling broadcast cables, complete with ends, in for special broadcasts from a remote truck to a stage. After the shot it all gets pulled out and everyone goes away. We had to use 8" irrigation type pipe with custom made sweeps. 8" trade size is not made in listed PVC conduit.
Posted By: Trumpy Re: US Conduit Sizes? - 12/11/02 04:25 AM
Rick,
Those are strange Metric sizes.
Our sizes over in NZ here are(OD)
16,20,25,32,40,50 and 60mm.
It comes in Grey Medium Duty, Orange for where Chemical Resistance is required and
Black Heavy duty for where rugged mechanical
protection is required.
We also have flexible corrugated PVC conduit,
in these sizes.
Posted By: jdevlin Re: US Conduit Sizes? - 12/11/02 02:38 PM
How do they determine the metric equivalent sizes. 1/2" = 13mm. Is the #16 actually larger than 1/2".
Posted By: CTwireman Re: US Conduit Sizes? - 12/11/02 03:40 PM
Trumpy, the reason they are strange measurements is becasue they simply took the customary English trade size (0.5", 0.75", etc) and converted it to a metric equivalent measurement. They didn't actually change the size of the conduit to a more "round number" metric size.
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