Help me right a wrong (subpanel) ...

[rust buster]

I'm hoping that there is a good electrician on the board that can help me right a wrong. I have 200A service to my house. I have a detached shop that is about 100' from the panel. The previous owner of the house put a 100A subpanel in the shop. The outside portion is in 2" PVC conduit underground from building to building. The wire used is 2 2 2 4 aluminum USE-2 XLP. The interior portions are not in any conduit, just stapled to joist/studs and terminated in each panel. The shop panel has a 100A main shut off and the neutral and ground are not bonded. The house main service panel is bonded and has a 100A breaker for the subpanel.
There does not appear to be grounding rods outside the shop.

So my questions...
Did they use the right wire/cable?
Does the interior portion have to be in conduit all the way to each panel? I am reading conflicting stuff online. Some say that USE-2 is not allowed at all inside, but other are saying it is if it is XLP.
I think grounding rods are required outside the shop?
Any info is appreciated!

 

[Falcon67]

From what I've learned on this over the last couple of years - taken with a volt of salt

At the very least, you need ground rods at the detached building. 2 ea 8' long, 6' apart. Unless the shop uses a UFER ground - ground buss bar tied to rebar in the foundation. If it's a UFER then you are OK on that part.

My local had no problem with 2-2-2-4 mobile feeder inside - YMMV.

2-2-2-4 AL is really only rated to 90A in that application - but many locals allow it for 100. Mine does. You can always change the breaker in the feeding panel if it's a problem.

 

[rust buster]

Thanks! The wires are not in a common insulated jacket. The 4 wires are individual and wrapped around each other in a spiral...that's why I am assuming they need to be in conduit all the way...which is going to be a pain to fix.

 

[Zeke]

The wires might only need to be "protected." For this you might be able to cut some conduit down the middle and place it over the wires with straps. Or just box it in.

 

[pattenp]

Not all XLP cable is the same. USE-2 rating alone is not fire resistant rated insulation and wiring carrying just that rating is not to be run inside. XLP insulation is a cross linked polyethylene and is rugged for direct bury purposes. Any single wire cable that is twisted and has no outer sheath needs to be in conduit or ducting when run inside. You need to get the full id numbers and brand of cable to find out if it does have the required insulation to be run inside. Some wire will carry a FR-XLP marking which means Fire Retardant XLP. Also markings of RHH and RHW-2 are fire resistant ratings.

Edit: The plain XLP got me scratching my head because I remember some info I searched a while back and it was listed as a flame resistant insulation. So checking again it seems that XLP is flame resistant so the wire you have should be okay inside. But it still needs to be in conduit.


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[rust buster]

Not all XLP cable is the same. USE-2 rating alone is not fire resistant rated insulation and wiring carrying just that rating is not to be run inside. XLP insulation is a cross linked polyethylene and is rugged for direct bury purposes. Any single wire cable that is twisted and has no outer sheath needs to be in conduit or ducting when run inside. You need to get the full id numbers and brand of cable to find out if it does have the required insulation to be run inside. Some wire will carry a FR-XLP marking which means Fire Retardant XLP. Also markings of RHH and RHW-2 are fire resistant ratings.

Edit: The plain XLP got me scratching my head because I remember some info I searched a while back and it was listed as a flame resistant insulation. So checking again it seems that XLP is flame resistant so the wire you have should be okay inside. But it still needs to be in conduit.


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Thank you! That makes me feel a bit better knowing that I don't need to get new wire for the inside portion. Now to just put it all in conduit... At least I have open truss joists so that will make it a little easier. Wonder should I keep it 2" inside or go a little smaller?