I’m doing DIY electrical…200 amp entrance panel feeding two 100 amp sub-panels. My electrician stopped by Saturday morning (I paid him for consulting), and specified my choice of two cable sizes, whichever was available, to run from breakers in the entrance panel to the sub-panels. These will be runs of ~ 16 – 20 feet.
I wrote the wire guages he specified on the sheathing which is now covered over.
I think it was 4-4-4-6 if copper and 2-2-2-4 if aluminum. Does that sound right?
TIA
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Replies
the alumin is always bigger. anyway the number represent the size wire for each leg so 4,4,4,6 (4) positive, hot (4) postive, hot (4) netural (6 ) ground
He also told me this was commonly available in cable...they don't have any at Menards...guess I'll check HD.
Cable this size is really hard to bend. If its not a real easy run, think about conduit and individual conductors.
I might need to go that way...but these are really easy runs in crawl spaces....electrician said I could fasten this stuff directly to the bottom of the floor joists in the crawl space.
crawl space might be legal but in a basement it would be a code violation, They do not like attachment on bottom of joist
For cable this big (not smaller than 2 #6 or 3 #8), attaching to bottom of joists is OK, according to NEC.
Just watch out for the bends. Minimum radius is around 6 inches I think. It handles more like pipe than like wire.
When you go to buy the wire, pay attention to the temperature rating. It should be marked on the insulation. It may be marked 60 degrees C, 75 degrees C or 90 degrees C.
#4 copper wire or #2 aluminum wire are OK for 100 amps, IF they are rated for 90 degrees C temperature rise.
I don't believe 60 degree C wire is very common, but you may find your store carries 75 degree C wire. In that case, use #3 copper or #1 aluminum.