SE Type U for Feeder?

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Bloose

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Hello All,

I am a maintenance electrician and deal a bit with Industrial installations in our plant. Unfortunately I am a bit rusty when it comes to residential. Also, most of the guys I work with are in the same boat. I'm glad I found this site as I am learning a lot just reading through the various posts.

Here is my situation. I am building a detached garage at my house. I installed a 100A sub panel in the garage and am planning to feed it from my main panel in the house. I ran 2 inch rigid Sch 40 PVC between the house and garage (appx 60 feet). I would like to run aluminum conductors to the garage. I've already bought 120ft of 2-2-2 SE typeU Al cable for the job. But I'm thinking SE is not the correct stuff. I am also planning to run 3 conductors out there and install 2 ground rods (already done) at the garage. Also, I need to run about 20 feet inside of the basement to get to the main panel and I'd prefer not to run it in pipe all the way if I can avoid it.

My questions are can I use the SEU? I'm also thinking 2-2-2 AL is not the correct size because I don't think I can use the dwelling unit exception for the garage? If SEU cannot be used in this situation what should I be using? UF? URD?

This job is not going to be inspected (no inspections in my area) but I still want it to be right.

Thanks for any help
 
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#2 Aluminum is to small for 100 amp @ 240 volt. You need to up size to 1/0 KCML aluminum.At 200 feet that would only be a 2.71% voltage drop. I would use pvc pipe the complete run sch 40 even into the house.
 
60' of #2 would be ok for residential garage. Also, pull USE, URD or THHN-W. Why not just pull 2 ungrounded conductors, one grounded conductor (Neutral) and one EGC, isolate grounding and grounded conductors (neutrals) at the sub panel and forget about driving additional rods. Just my thoughts only.
 
SEU is not direct burial even in conduit. Run 4-wire for the EGC to the subpanel. Tradeoff for avoiding conduit through basement would be SER AL from main to j-box at structure exit transition to lateral conduit run to garage with cabling such as XHHW or triple rated type RHH, RHW, USE. Another option allowed would be MC run for the whole distance without conduit except for riser protection. These are solutions I have experienced in the past. Other forum members probably have a better solution that may be to your configuration.
 
dcspector said:
60' of #2 would be ok for residential garage. Also, pull USE, URD or THHN-W. Why not just pull 2 ungrounded conductors, one grounded conductor (Neutral) and one EGC, isolate grounding and grounded conductors (neutrals) at the sub panel and forget about driving additional rods. Just my thoughts only.
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I thought the ground rods were required regaurdless. If I buy new cable, which it looks likely I will have to, I will likely get 4 conductor. This way if I ever run any metal from the hose to the building I'm covered.

Thanks for the help so far.
 
I thought I'd mention also, when I purchased the cable I was told it was USE. When I got home and looked at it it is marked SE typeU XHHW-2. I don't think USE would have been OK inside of the home though, so that wouldn't have worked either.
 
gndrod said:
SEU is not direct burial even in conduit. Run 4-wire for the EGC to the subpanel. Tradeoff for avoiding conduit through basement would be SER AL from main to j-box at structure exit transition to lateral conduit run to garage with cabling such as XHHW or triple rated type RHH, RHW, USE. Another option allowed would be MC run for the whole distance without conduit except for riser protection. These are solutions I have experienced in the past. Other forum members probably have a better solution that may be to your configuration.
Click to expand...

Please provide a ref restricting SEU for UG raceway


thanks
 
338 NEC discusses USE....I believe UL white book. If SER. SEU is rated for that purpose in conduit underground (which is not a dry location) then fine. BTW......SER...R denotes (round)....SEU...U denotes (U-shaped)...USE on the other hand is Underground Service Entrance.
 
Yea I know some of that old school stuff was the way to tell the difference to new people in the past. I will tighten up.....thanks...I have not always been an Inspector.
 
Gents,

Table 310.15(B)(6) would allow #2al. for 100amps. also as Bloose has

indicated the SE-U / XHHW-2 , would be good for a wet location. With no

other metalic paths to the garage, He could use the materails that he has.

Bloose, Do you have a main disconnect in the garage sub-panel? If not I

think you need one, also, you are correct about the ground rods they are required.

Bloose, if you use the SE-U follow 250.32(B)(2)
 
For some reason, my link doesn't work, but here is the quote from Southwire:

Code: 
[B][FONT=Arial]SEU:                 S[/FONT][/B][FONT=Arial]ervice [B]E[/B]ntrance Cable, [B]U[/B]narmored. Usually type [/FONT]
[FONT=Arial]XHHW insulated conductors with overall PVC jacket. As such, the cable is rated for [/FONT]
[FONT=Arial]90[/FONT][FONT=Symbol]?[/FONT][FONT=Arial]C dry, 75[/FONT][FONT=Symbol]?[/FONT][FONT=Arial]C wet locations. Another school of thought is the "U" in the designation [/FONT]
[FONT=Arial]denotes the shape of the cable (if you look at the end, it resembles a closed "U" [/FONT]
[FONT=Arial]shape).[/FONT]
 
[B][FONT=Arial]SER:                 S[/FONT][/B][FONT=Arial]ervice [B]E[/B]ntrance Cable, [B]R[/B]ound. Same construction material-wise as [/FONT]
[FONT=Arial]SEU, but round construction affords use of more than 3 conductors to which SEU is [/FONT]
[FONT=Arial]limited.[/FONT]
Click to expand...
 
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