Is a disconnect permitted between Service Panel and Subpanel?

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TomWS

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I have 200 A main service panel and want to add a subpanel at an opposite corner of the house. The original owner had a length of 8/3 cable installed in the service panel in anticipation of installing a hot tub. The original owner didn't install the hot tub and the cable is lying dormant midway in the crawl space and the service panel end is not yet connected to any OCPD.

What I would like to do, to save tearing up walls to install a new cable, is to wire the existing 8/3 to a 50 amp, 2 pole breaker at the service panel, install a 60 amp disconnect in the crawlspace to connect the other end of the existing cable and extend from this disconnect to the subpanel, which is another 20 feet away. The disconnect will maintain connected but separate neutral and ground and essentially serves as a high current J box. The subpanel will also have separate Ground and Neutral as per code. The subpanel is locate in the same building so a main lug panel will be used.

I haven't found anything in the code that addresses this. Does anyone have any pointers???

Thanks in advance,
Tom
 
8/3 must be used with a 40 amp breaker not 50 amps as NM cable is only rated 60C. As long as the 6/3 nm has a ground then there should not be an issue with the install.
 
I would just make the disconnect a jb and be done with it, if the wire is in the disconnect already otherwise I think a jb is the way to go also.
 
I would be concerned over working clearance for the disconnect. You won't have the minimum of 6'-6" of height, and I don't think the exception to 110.26(A)(3) will apply. But do you need a disconnect at all? How about just installing a junction box in the crawl space?
 
WOW!

WOW!

What fast and great replies! Thanks!

I'd love to use just a junction box but, in my ignorance, I'm not sure what size/kind of box to use and what do I use for slices?

I figured a disconnect had all the appropriate lugs to tie everything together. Also, I can dial back on the main panel OCPD, the subpanel probably won't have more than 3 15 amp circuits and max's at 4 1" circuits.

Tom
 
Just use 8x8 junction box with butt splice lugs and rubber tape and finish with electrical tape.
 
You're only connecting two #8's x 3, and three #10 grounds. Should be easy with wire nuts, no butt splices or taping required. Because the conductors are smaller than #4, you just do a cubic inch calculation (7 * 3 = 21 cu inches required). But I'd go with a larger box than that, perhaps a 4 5/8 square x 2 deep to give yourself some working room.

If you don't want to wire nut three #10 grounds, screw a 5 hole CH ground bar to the box and use that ground bar as your terminals.
 
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