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Posted By: Active 1 #3's in 1" - 05/26/05 01:01 PM
I may be helping another EC install new panels in some condos. Need to run the feeders to each unit for a 100a panel. The runs will be 100-180'. No good strait shots and probibly a number of obstructions. We may need to install some pull boxes because of all the bends.

I would like to use 1 1/4 EMT with 3 #2 or #3's (depending on length) because it will be reasonable to pull by hand. The other EC is thinking 1" EMT with 3 #3's because it is quicker to bend and would save maybe $1500 in material.

The inspecter already said 3 #3's is fine in 1" and is not worried about VD because of little load in each unit.

I never tried to pull 3 #3 in a 1" very far by hand but I wounder if it is possable with out a tugger.

Tom
Posted By: Celtic Re: #3's in 1" - 05/26/05 07:29 PM
Code wise...3 #3 thhn's in a 1" EMT do fit, but just barely ~
1/2" = 1 #3
3/4" = 1 #3
1" = 3 #3
1 1/4" = 6 #3
...that 1/4" makes a HUGE difference!


I recall a job I did where 11 #10 XHHW conductors were pulled in a 3/4" RGC for stub-ups(code allows 11 @ 3/4")...the rope broke once, the guys were POed at me all day...and it took 4 guys just to pull ~ not including the guys at the feed end. After this fiasco(which took about a 1/2 day to go just over 100'), I had the crew start running "extra" 3/4" conduits overhead.
The amount of effort that was required to get the wires in was not worth it.


For you, a small tugger(gets attached to a RA drill or hole hawg) might be a viable alternative...pay for it once, use it over and over again.
Posted By: Tom Re: #3's in 1" - 05/26/05 10:17 PM
I've been down that road exactly one time and I learned my lesson. You might try the 1" for some of the shorter runs, but I'd strongly advise going to the 1 1/4 " EMT for anything with more than two 90 degree bends. If you opt for the 1", let us know how it went.

Tom
Posted By: Tiger Re: #3's in 1" - 05/27/05 12:32 AM
It's physically possible to pull four 3ga. wires in 1" IMC. With some lube you shouldn't have any problem. Additional pull points to keep it to two bends per pull will help. I recently PUSHED three 3 ga. in 1" IMC in short runs with one bend.

Dave
Posted By: Celtic Re: #3's in 1" - 05/27/05 04:41 AM
1" IMC is NOT the same as 1" EMT...1" IMC is allowed 4 #3's, 1" EMT is allowed 3 #3's.

Pushing 3 #3s in a 1" IMC is no special feat.
Posted By: Tiger Re: #3's in 1" - 05/27/05 11:56 AM
Right Celtic, I missed that one.

Dave
Posted By: rcksmith127 Re: #3's in 1" - 05/27/05 12:26 PM
I don't know what area you are in but I'll tell you in the NorthEast, more and more MC and believe it or not SER is being used in the residential hi-rises. (Condo's Apartments, Dormitories
Engineers, inspectors and even the contractors are pushing it.
Posted By: William Runkle Re: #3's in 1" - 06/03/05 12:35 AM
Have you thought of derating the neautral? Two number threes and a four or six.
Posted By: Active 1 Re: #3's in 1" - 06/03/05 03:48 AM
Thanks for the replys.

Local thing min size 3 #3 for 100a residential.

After a bit I think we would be better off doing a larger pipe with a few sets of feeders. I'm thinking about a 2" with 9 #2's until it gets near the unit.

Tom
Posted By: e57 Re: #3's in 1" - 06/03/05 08:15 AM
Funny.... Local PoCo here requires 1 1/4 min. for resi. (2" U/G) And Rare to find #3 stocked anywhere, almost like it doesn't exist. #4 - #2!
Posted By: e57 Re: #3's in 1" - 06/03/05 08:17 AM
Oh, you can use 1" only for signage only service's.
Posted By: Active 1 Re: #3's in 1" - 06/03/05 02:49 PM
The service is thru a meter center. Their local requirements is normally 1 1/4 but the inspector said they would allow 1" for this building.

Tom
Posted By: Active 1 Re: #3's in 1" - 06/03/05 02:52 PM
Getting #3 at the supply house is no problem here. Last I checked #3 was not much cheaper then #2. But it adds up if you need a lot.

Tom
Posted By: luckyshadow Re: #3's in 1" - 06/03/05 04:06 PM
when you say "meter center" is this a meter bank with disconnects built in ? If so won't you need a ground also?
Posted By: Active 1 Re: #3's in 1" - 06/03/05 05:50 PM
Yep a meterbank with discos. Equipment ground not required for RMC & EMT. Would like to run one. Can do 3 #3's +#8 in 1" but not #2's. Whish I was doing it and not writting about it right now.

Tom

[This message has been edited by Active 1 (edited 06-03-2005).]
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