SE cable

[Charlie Bob]

I'm working on a subpanel fed from a 3 phase main panel board. it is on an old gym. i'm gonna put a 100 amp subpanel. i'm gonna remove the existing AL SE #6 three wire. there's a riser of 1" emt from the old subpanel into the attic and another one from the main panel box into the panel as well.
I thought about using 3-3-3-5 SE cable as a feeder.
somebody told me one is not supposed to put SE in conduit. I checked code book and didn't find anything to that regard.

Is this true? I thought, if you use SE as a feeder or branch circuit in other than a dwelling unit it needs to be in conduit.

Thanks.

 

[augie47]

A few couple of concerns come to mind:
(a) If SER is installed in conduit, Not 9 of Table 9 would require a rather large conduit.
(b) SER under the '08 Code would only have an 85 amp ampacity in Cu, and a 65 amp in AL.

 

[Charlie Bob]

yeah i'm gonna use a bigger conduit, i was just let you know what is there now. But i'll use risers from each box. I was just wondering if this was mandatory, to provide protection.

isn't 100 amp, the ampacity acording to the 75 column, or i should choose the 60 column since this is SE cable?

My supplier told me that was what everybody use, 3-3-3-5 for 100 amp.

 

[infinity]

yeah i'm gonna use a bigger conduit, i was just let you know what is there now. But i'll use risers from each box. I was just wondering if this was mandatory, to provide protection.

isn't 100 amp, the ampacity acording to the 75 column, or i should choose the 60 column since this is SE cable?

My supplier told me that was what everybody use, 3-3-3-5 for 100 amp.

Under the 2008 NEC the use of SE cable for interior installations requires the 60 degree ampacity.

 

[Charlie Bob]

Thank you.
So by using 60 C column, can i still use #2 even though the ampacity is 95 amp?

 

[curt swartz]

You could use #2 CU SER if your calculated load is <95 amps. If you are going to install a raceway why do you want to use SE cable? Running individual conductors would be less expensive and more professional.

 

[Charlie Bob]

You could use #2 CU SER if your calculated load is <95 amps. If you are going to install a raceway why do you want to use SE cable? Running individual conductors would be less expensive and more professional.

this a very old building, with a lot of stuff right above in the attic. Running conduit all the way would be not impossible but really hard.
I thought about running conduit from each box into attic and install a bushing and leave the SE in between. It would protect the wire where is visible and would look better and would ease the instal;lation as well.

 

[Charlie Bob]

I talked to inspector today, he told me that 3-3-3-5 SE would be appropriate, he is using 90 C column, since THHN is what SE cable has.

 

[LarryFine]

I talked to inspector today, he told me that 3-3-3-5 SE would be appropriate, he is using 90 C column, since THHN is what SE cable has.

This is the point when you say "Thank you" and don't bring it up again.

 

[kbsparky]

I talked to inspector today, he told me that 3-3-3-5 SE would be appropriate, he is using 90 C column, since THHN is what SE cable has.

I have never seen any SE cable with THHN conductors. I believe that most of it has XHHW conductors, however.

 

[Dennis Alwon]

I have never seen any SE cable with THHN conductors. I believe that most of it has XHHW conductors, however.

You are correct however, the point is that it is 90C wire. This, of course, doesn't matter, unless you need to derate, either since we are limited to 60C anyway.

I would use a 90 amp breaker as long as the calculated load is not greater than 85amps.

 

[jmellc]

I talked to inspector today, he told me that 3-3-3-5 SE would be appropriate, he is using 90 C column, since THHN is what SE cable has.

3 3 3 5 Cable?? I never saw a size 5 conductor that I remember, and it's not in the tables. Am I missing something here?

 

[slick 50]

3 3 3 5 Cable?? I never saw a size 5 conductor that I remember, and it's not in the tables. Am I missing something here?

You will still have to derate the 110 amp by 80% since there are more than three ccc in the raceway or cable...right???

 

[Dennis Alwon]

You will still have to derate the 110 amp by 80% since there are more than three ccc in the raceway or cable...right???

Hey slick, this thread is 3 months old.