wire size.

[tyler]

hey guys and girls need some advice.
I am looking to run 40 amps out to my shed to run compressor and lights. I already have a panel for inside the shed that handle 100 amps (over kill but good kijiji deal) and have the room in my panel inside the house but I am looking for wire now. I would like to use teck 9 so that I can do direct burial at 18" deep. the only issue I am having is finding the 8awg required for 40 amps. I have been able to find one left over chunk that is long enough but the issue is that its apparently 1awg (the guy used it for 60amp run to his garage, and is selling the left over piece.). my Question is would I be able to legally use the larger cable for my application.

[suemarkp]

Generally yes. However, there are a few things to consider:

#1 most likely won't fit the lugs of a 40A breaker. I'd consider going up to at least a 60A breaker and if its lugs will take #1 then great. If not, consider going even larger with the breaker. They do begin to get more expensive, but 100A breakers are usually a bit cheaper because they are much more common. A #1 should fit in a 100A breaker with no problem.

Do you have enough panel bending space for that wire? Code requires a certain distance between the breaker lug and the panel wall. That distance depends on wire size. I don't know you panel dimensions nor the canadian bending space rules, but most panels are usually designed to accommodate a 100A breaker with copper wire. So #1 may be close.

If you just want to use a 40A to 60A breaker with the larger wire, then you'll need to pigtail on a smaller wire to fit the breaker lugs and meet the bending space requirements. You could use a split bolt or one of the tubular set screw type of splices. But these need to we wrapped with splicing tape and then electrical tape on top of that because most are just metal (no plastic insulator around it). There are Burndy brand splices that don't need any tape if you can find them. The neutral and ground bars probably have lugs large enough for this, but make sure there are still enough available larger size lugs for this or you'll be needing pigtails on these too. I've not seen any wire nuts listed for #1 wire.