Sub-Sub Panels?

[pfbz]

New hot tub going in our mountain house. Trying to figure out how to get it wired...
.

• Builder originally put in a 50A sub-panel specifically for hot tubs, but not in the right place. No breakers currently installed in it.
• Hot tub came with a 50A sub panel with 30A-220V-GFCI and 20A-110V-GFCI breakers and a 20' ultratite whip.

Two problems with the existing sub-panel... First, although within 50' of the hot tub, not 'within sight'. Builder put panel is on second floor deck and d the hot tub is underneath it at ground level. Second, wired sub panel is BR type, and the GFCI breakers that came with the hot tub are CH type.

I'm considering a few options, but wondering about this one:
.

• Install a 50A non-GFCI breaker in the existing above deck sub-panel.
• Off that 50A breaker, run four 8AWG (hot, hot, neutral, ground) in flextite to feed second hot tub specific sub panel.
• Use the new second panel GFCI circuits to power hot tub through whip.

Can you do that?

Does NEC and/or good practice allow wiring a 'sub-sub' panel?

[I'm sure 200 people will feel compelled to say 'hire a licensed electrician', which I should and probably will do, but I'd like to know the answer to the question anyway...]

 

[Bib Overalls]

Replace the original sub-panel with a weather tight junction box (or use the sub-panel as a junction box) and make a splice.

 

[malibu101]

Almost sure you can run a sub off of a sub. Don't quote me on that tho.

But I think what Bib Overalls said above is on target--
The way the existing out of sight panel is installed; Can it be changed it a junction box?
And then run the wire to the new panel location?

 

[pfbz]

...use the sub-panel as a junction box and make a splice...

Hmmm... Simple, cheap, and after a bit of googling, sounds like it is code compliant. Sounds good!

From another forum and thread, evidently from 2011 NEC code:

312.8 Switch and Overcurrent Device Enclosures with
Splices, Taps, and Feed-Through Conductors. The wiring
space of enclosures for switches or overcurrent devices
shall be permitted for conductors feeding through, spliced,
or tapping off to other enclosures, switches, or overcurrent
devices where all of the following conditions are met:

(1) The total of all conductors installed at any cross section
of the wiring space does not exceed 40 percent of the
cross-sectional area of that space.

(2) The total area of all conductors, splices, and taps installed
at any cross section of the wiring space does not
exceed 75 percent of the cross-sectional area of that
space.

(3) A warning label is applied to the enclosure that identifies
the closest disconnecting means for any feedthrough
conductors.

Just use wrapped split-bolts or big twist nuts to splice the 6 or 8 AWG wire?

 

[zmaxmotorsports]

Yes use split bolts for anything that big.I wrap them first with 3m super 33 tape,Then I go over that with 2-3 wraps of good rubber splicing tape and again with the super 33 after that.

 

[Stuart in MN]

As long as it's installed properly, there's no problem with running a subpanel off another subpanel.

 

[fnsane]

Enjoy electrocution.

 

[yeldogt]

When I extended my pool sub panel we used a box suitable for a splice and extended it -- the connections were made with large (very) wire nuts. In that case my inspector said it could not look like a disconnect -- so I pulled in back into the garage and spliced it inside.

We did the same with our hot tub and replaced the box with a disconnect -- not a breaker .. and ran it to the new sub-panel.

In my case everything was square d and they make a non fused disconnect that looked and fits in the panel like a breaker. I don't remember why I had to switch out the breaker .. but our inspector is particular.

 

[Beemer533]

Enjoy electrocution.

 

[ctgoodman]

Replace the original sub-panel with a weather tight junction box (or use the sub-panel as a junction box) and make a splice.

^^^^^ This... It should be code compliant and less confusing as you will not have to jump through that panel to get to the one at the hot tub.

 

[volleyball]

Many of those tub panels have tabs so you can put a lock on it which would make it a junction box. That way when you move the hot tub upstairs, it will have the proper box ready to go.