use-2 vs xhhw

[jkr1282]

Sorry if this has been answered already but so many variables .
Installing 100amp subpanel in garage with 90amp breaker in main panel 100ft from indoor 200 amp service entrance panel -30ft inside basement between joists (no conduit), 20ft in crawl space pvc conduit, 30ft under deck in pvc conduit, 20ft 18" underground in conduit into garage. I talked to inspector who wants USE or USE-2. Can this be done since USE cant be run inside and what size conduit would be best for pulling wires. Aluminum or Copper - 2/0 with 4/0 ground and how high should the entrance to the garage be.
Thanks

 

[suemarkp]

Many USE type conductors are dual listed as USE and RHW or some similar allowable listing. But you have to watch USE type as there are individual USE conductors and there are USE cables (multiple conductors in a jacket). You can't run the individual USE conductor type inside without conduit (even if dual listed as RHW). USE cable don't need conduit, but can't be run inside either.

If you can't find a dual listed USE, then run conduit the whole way (even flex conduit) so you can use any individual conductor rated for wet areas such as THWN, XWWH, RHW, etc.

Why such large wire for a 90A feeder? #3 copper or #2 aluminum would be fine for a 90A feeder. #4 copper could work if the calculated load is 85A or less. UF cable would also work for this if you can find it in #4 copper as it can be used inside like Romex and direct buried. Not ideal to run in conduit though, as it is flat and wide.

 

[Dennis Alwon]

I am closing this thread, in accordance with the Forum Rules.

This site is designed for:

• Contractors
• Electricians
• Engineers
• Inspectors
• Instructors
• Other electrically related individuals

* This NEC Forum is for those in the electrical and related industries. Questions of a "How-To" nature by persons not involved in the electrical industry will be removed without notice.

If you feel this action to be in error, feel free to contact me via PM to explain. Reminder to all members, if you see a questionable post, feel free to report it by clicking "Report" at the bottom left corner of the post.