2011 338.10

[ceb58]

In looking over the changes in the 2011 I want to make sure I have it correct.
338.10 (B)(4)(a) is now stating that the amp rating of SE can now go back to the 75 deg column as long as it is not installed in thermal insulation.
So dose this mean that if you install a 200 meter/combo with feed through lugs and the SER doesn't run through thermal insulation we can go back to using 4/0al or doing 2 back to back panels on a 320amp service as long as 240.4 is met?

 

[Dennis Alwon]

Well you can go back to back with 4/0 aluminum in ser cable as long as the calculated load is not more than 180 amps. I have a 400 amp service we are working on now where we moved the panels and have to re-feed them. I used 2" pvc and I could use 4/0 alum or 3/0 copper with 200 amp OCPD. Again with aluminum the calculated load must be 180amps or less.

 

[Dennis Alwon]

An inspector in our area says if you sleeve the ser cable in 2" PVC down an insulated wall then they will allow the 75C rating. I think this is not the intent but...