Anyone know if 4-O Aluminum Triplex can be run in 2″ Sch 80 PVC conduit (with 6 gauge ground). 200amp subpanel, to be run under a deck over water.
Thanks for any insight….
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Replies
What's the diameter of your cable?
The NEC says to consider a multiconductor cable as a single conductor when calculating conduit fill. For a single conductor, the allowed fill is 53%. A 2" schedule 80 PVC conduit has an I.D. of 1.939" (per the Carlon catalog), for a total area of 2.953 square inches.
53% of 2.953 is 1.565 square inches, which works out to a maximum cable diameter of 1.412" So, if the aluminum triplex is 1.4" in diameter or less, it should be okay.
Stuart,
It is the standard Triplex that is used for new 200 amp service. I'm far away from it right now, but, i think it meets the criteria you provided. I'll check. I'm guessing the gap requirement is for cooling? So that would be dependant on material type?
Thank you.
Chris.
'has nothing to do with cooling. These are guidelines for a feasible pull.
How long is the run? 3" is LOTS easier to use with this stuff.
Note if this is the type with an uninsulated neutral, there are restrictions concerning its use as a feeder.
55' three 90s.
lube, #6 solid ground. pulling, the ground first, then the tri-plex.
so there is no known issue with putting tri-plex in conduit? somehow i thought there was a heat dissipation issue.
I don't know offhand the diameter of that stuff, if you have a brand and part number you can probably find the manufacturer's catalog online and get the diameter from that.
From your last post it sounds like the ground wire is separate...that would mean two conductors (for the purposes of calculating conduit fill per NEC) and that means you're only allowed 31% fill - it's harder to pull two wires through a conduit than one, which is why they require more free space inside the pipe. You'll have to calculate the cross sectional area of the triplex, plus the cross sectional area of the ground wire, add them together and compare them to 31% of the pipe cross sectional area I posted earlier.
I'm an engineer so I can read the tables in the NEC, but the electricians here like Barry have a lot more experience in what actually works in the real world. I'd tend to agree with him that 3" conduit would be a lot safer bet.
Our 4/0 feeders were always pulled in 3" conduit. Ignoring the fill requirements issue, it sure is easier than in 2". That stuff is not very flexible <g>. Make life easy, go a size larger. My Electricalc is in CA, so I won't do the numbers.
Will they let you use a pair of 45s with a run between vs a 90 to ease the pull?
Going to use a 3/8 poly for the pull cord?
FWIW - while we would pull the 4/0 feeders in 3", the telcos wanted their run done in 4". On one roof cell site job, I pulled a grand total of four Cat 3 cables from basement telco room to rooftop cell site in that 4" conduit. Room for future expansion.
The ToolBear
"Never met a man who couldn't teach me something." Anon.
Pulled it twice!
Forgot the ground wire (#6) the first time. Pulled it back out (with poly 3/8" or 1/2"), fed the #6 and pulled the tri-plex through again, much easier the second time.
we'll see if the inspector likes it. he seemed okay with it when i asked prior to the pull.
Thanks.
@@ Pulled it twice!
Forgot the ground wire (#6) the first time. Pulled it back out (with poly 3/8" or 1/2"), fed the #6 and pulled the tri-plex through again, much easier the second time.
we'll see if the inspector likes it. he seemed okay with it when i asked prior to the pull.
Twice? Ah, memories. BTDT. I prefer to assemble something then look over to see that the widget that should have gone on the wire first is sitting right over there.
Inspector happy = you happy. Get him to sign it off. Keep a copy.The ToolBear
"Never met a man who couldn't teach me something." Anon.
i'll let you know what he says...
I prefer to assemble something then look over to see that the widget that should have gone on the wire first is sitting right over there.
'been there, done that: about a million times. ;)