wyliesdiesels
Well-known member
wow thats a ****** calculator
Wire and conduit selection for 100A feed to sub panel?
- Thread starter Zaxxn
- Start date
Innovate1
Well-known member
90A for 20 feet. I only need #12 copper per that calculator. I am going to save a lot of money on my rewire project. LOL!
Ok, decisions made with the great info on this thread. I will be running 1.25" Schedule 40 through the basement to match the conduit to the slab. Using LBs and sweep 90s where appropriate and running 3x #2 XHHW-2 AL and 1x #4 XHHW-2 AL on a 90A breaker. Going to be a tough pull with just about 100' total...
Now, the XHHW-2 AL seems to only come in black or green. Phase marking wouldn't be an issue since it's single phase and I can get green for the #4, but the neutral needs to be marked - is tape wrap on the termination points sufficient for that?
Thanks,
Zax
Now, the XHHW-2 AL seems to only come in black or green. Phase marking wouldn't be an issue since it's single phase and I can get green for the #4, but the neutral needs to be marked - is tape wrap on the termination points sufficient for that?
Thanks,
Zax
pattenp
Well-known member
Yes, just tape the ends of the neutral with white tape. Actually the ground only needs to be #6 for up to 100A.
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But will have to have green colored insulation because it’s #6.
alfredeneuman
Well-known member
If it is stripped bare wherever it's visible it doesn't need to be green.
mike93lx
ALLIANCE MEMBER
Should it be stripped as soon as it enters the panel or right before?
Always hitting one snag or another it seems. I can't find any local supply house carrying any XHHW in AL in green....only black, and only CU is available in green. Seems odd, since it's pretty clear you can't tape a ground. And using the copper is triple the price, but it almost seems like I have to bite the bullet if I want to get this done. Also, I think to ground/bond my gas line, I need #6 CU anyways...so not much choice. But can I mix 3 black #2 AL XHHW with one green #6 CU for the feeder to the sub panel?
Code say's you can't re identify the green. But in my experience everybody does it once in a while.
My electrical supplier stocks black only in the local branch but they stock many colors in another branch an hour farther away. If you ask they will cut it and transfer to the local branch.
My electrical supplier stocks black only in the local branch but they stock many colors in another branch an hour farther away. If you ask they will cut it and transfer to the local branch.
pattenp
Well-known member
Just use a black #4 Al XHHW, it can be marked as green. #6 and smaller are not to be reidentified.
I wish I had a well stocked supply house close by...but at least I ran into a friend that happened to work there that hooked me up. So, I ended up with 3 #2 XHHW AL black and 1 #6 XHHW CU green for the panel feed and the same green #6 XHHW CU green for the bonding wire for the gas line. I think that should work.
Someone had mentioned in the beginning of the thread to check the panel if I can put the 90A breaker I will use in the new panel also into this one until I upgrade the service, but I can't find any indication about the max allowed panel. "Old" 100A panel is new-ish and a Siemens as well, just like the new 200A panel I am replacing it with, same style. "Old" panel is a G2020B1100 and the only thing I could imagine having that meaning is the rating "125A Maximum - See main breaker rating if used". Does that mean even though it's a 100A panel, the bars are good for up to 125A so I should be fine using the 90A breaker instead of buying another, smaller one only to never use it again?
Sorry for so many questions, but I always rather ask first than fixing later.
--Zax
Someone had mentioned in the beginning of the thread to check the panel if I can put the 90A breaker I will use in the new panel also into this one until I upgrade the service, but I can't find any indication about the max allowed panel. "Old" 100A panel is new-ish and a Siemens as well, just like the new 200A panel I am replacing it with, same style. "Old" panel is a G2020B1100 and the only thing I could imagine having that meaning is the rating "125A Maximum - See main breaker rating if used". Does that mean even though it's a 100A panel, the bars are good for up to 125A so I should be fine using the 90A breaker instead of buying another, smaller one only to never use it again?
Sorry for so many questions, but I always rather ask first than fixing later.
--Zax
wyliesdiesels
Well-known member
Typically, bonding wire is solid bare cu, not insulated stranded.
Well, let's hope he'll let it pass with the green THHN.
The pull went a lot easier than I would have thought. That insulation of the XHHW-2 is coated with something so slick that there was no need for any lube, even in the 1.25" conduit. Wife fed the wire, I pulled the tape and the LB before the last section of conduit out to the shop and through the slab was a big help too. The hardest part really was making sure to not get the 4 coils of wire tangled up with each other while pulling.
Thanks again for everyone's help in this thread - there is so much good information in here now that I really hope will help someone else down the road as well!
--Zax
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pattenp
Well-known member
Glad it worked okay for you. But I have to ask.... why did you use a main lug panel being that your main panel is at the other end of the house? A main breaker panel would have given you the convenience of a main disconnect in the shop if needed. Or is that the main hidden behind the wires?
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Definitely a valid question, pattnp! Answer as so often: Price!
Not because of the slight difference between them, but because this one came free and brand new in the box. So while I would have like a main disconnect in the shop, the main panel is just down the stairs and at the end of the hallway from the panel location in the shop. But since said downstairs is finished, it was a bit of a long run to get there by cable.
Not because of the slight difference between them, but because this one came free and brand new in the box. So while I would have like a main disconnect in the shop, the main panel is just down the stairs and at the end of the hallway from the panel location in the shop. But since said downstairs is finished, it was a bit of a long run to get there by cable.
EricVonHa
Well-known member
That's a helluva project. I feel your pain and know the feeling of final completion!
(Reading this thread late to the game...)
Couple years ago, trenched to an out-building with too small of a ditch witch. It worked, but definitely worth getting the mega ditch-witch. Nothing is worth struggling with and the smaller unit we used easily bound up on rocks slightly smaller than a baseball. Anyhow.. it worked begrudgingly with a bit more effort and time.
Installed were three (3) 2" conduits with roughly 125' run. One was for low-voltage network and I still have a spare conduit.
Reading through this brings back some memories on asking many electricians and reviewing code and finally talking with an inspector prior to doing the work. There was A LOT of confusion about how to ground the the remote building and connecting or not connecting the ground between panels and isolated neutral (ground loop anyone?)
IIRC, my out-building 100amp sub-panel has an isolated neutral buss bar. The sub-panel has its own ground rod that is pounded straight into ground. I remember asking the electrician that helped, "we have this huge ditch, why not lay the ground rod in it and bury it, ground is ground, right?" Ha! My guess is that too many people take this short-cut and when the inspector cannot see the tip of the ground rod, they start to ask for pictures.. anyhow, we passed with flying colors, did it right, and the electric has been error free for years now.
(Reading this thread late to the game...)
Couple years ago, trenched to an out-building with too small of a ditch witch. It worked, but definitely worth getting the mega ditch-witch. Nothing is worth struggling with and the smaller unit we used easily bound up on rocks slightly smaller than a baseball. Anyhow.. it worked begrudgingly with a bit more effort and time.
Installed were three (3) 2" conduits with roughly 125' run. One was for low-voltage network and I still have a spare conduit.
Reading through this brings back some memories on asking many electricians and reviewing code and finally talking with an inspector prior to doing the work. There was A LOT of confusion about how to ground the the remote building and connecting or not connecting the ground between panels and isolated neutral (ground loop anyone?)
IIRC, my out-building 100amp sub-panel has an isolated neutral buss bar. The sub-panel has its own ground rod that is pounded straight into ground. I remember asking the electrician that helped, "we have this huge ditch, why not lay the ground rod in it and bury it, ground is ground, right?" Ha! My guess is that too many people take this short-cut and when the inspector cannot see the tip of the ground rod, they start to ask for pictures.. anyhow, we passed with flying colors, did it right, and the electric has been error free for years now.