Conduit fill question

I have a question for the experienced electricians in the group. I need to
run a #4-3 type SER cable through an underground conduit. I can find
tables in the NEC that cover conduit fill limits for single conductors, but
not for cabled conductors. Is the cable considered a single wire for this
purpose or 4 wires? Thanks
Reply to
Tom Lager
Loading thread data ...
Per note 9 NEC 2002 Chpt 9 Tables, multiconductor cables are to treated as single conductor cable. Do get the correct cross section area from manufacturer specs.
Reply to
The cross section is the diameter, based on the widest dimension. If it gets twisted that will be the swept area when you pull it in.
Reply to
There is a table in the back of the book for cross sectional area. Find out what it is for one wire, multiply by 4, then check the other table for 40% fill area.
Reply to
MLR (newsreader) wrote in :
I thought that was correct, just wanted a second opinion. Per Mfr. diameter is .77" so I can use 3" conduit to meet 40% fill maximum. Thanks to all who responded.
Reply to
Tom Lager
Well .77 is way too high for #4 wire.
You are looking for area in SQ INCHES from table 5A sect 70-887 if it is aluminum. For copper it is in table 5 sect 70-884.
Copper = .0824 Aluminum = .0881
.0881 X 4 conductors = .3524
According to table 4, sect 70-882, you can use an 1-1/4" Conduit.
AEC Electric & Controls Michael R
Reply to
I think cross section is by area, not diameter. Therfore: ((.77^2)/(.4))^1/2 = 1.217. So, 1-1/4 inch conduit should be OK.
Reply to
Bob Eld
I chuckle every time I hear the question....How many #12s can you put in a half inch pipe. Someone asks.......What's the record?
I know you wanted a serious answer. Sorry I don't have one. :)
Reply to

Site Timeline

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.