Author Topic: Repurposing a hot tub circuit breaker  (Read 1794 times)

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Offline tealfixie

  • Posts: 10
Repurposing a hot tub circuit breaker
« on: July 29, 2018, 01:09 AM »
Hello FOG,
Just wanted to get some advice on some electrical  setups for my upcoming basement workshop. And don't worry I plan on hiring out the work to a pro. Just want to gather Intel.

Bought a house that previously had a hot tub. There is a 60a service panel that is now unused. It sits outside on the back corner of my foundation. I want to run a subpanel to my basement dedicated to the shop space.

Is there a way to reuse this spa circuit for my workshop such as wiring a subpanel to it? I plan on having 3-4 110 circuits and 1 220v circuit.

Also consider that the spa panel is about 20' closer to my shop area when compared to the main breaker panel. I want to find the most economical way since copper isn't cheap!


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Offline Sparktrician

  • Posts: 3746
Re: Repurposing a hot tub circuit breaker
« Reply #1 on: July 29, 2018, 09:03 AM »
It's very easy to re-use a breaker.  It's also possible to relocate the subpanel.  If I understand your message right, you could pull back the existing spa wiring to the basement and reinstall the subpanel there.  That said, be sure to have a qualified electrician fully inspect the existing wiring before doing anything.  Also, the run from the main panel to the subpanel needs to be continuous, without splices.  If there's any damage to the existing run, replace it.  Don't take a chance by re-using damaged wire. 
- Willy -

 "Remember, a chip on the shoulder is a sure sign of wood higher up." - Brigham Young

Offline Alanbach

  • Posts: 266
Re: Repurposing a hot tub circuit breaker
« Reply #2 on: July 29, 2018, 07:18 PM »
@Sparktrician - it sounds like his 60 amp breaker that used to feed a hot tub is in between his main panel and the basement. If the wires feeding that 60 amp breaker are good can he run the feed for his new sub panel from there to the basement, effectively making the existing 60 amp breaker the main for his new sub panel even though it is 20’ away?

Offline Sparktrician

  • Posts: 3746
Re: Repurposing a hot tub circuit breaker
« Reply #3 on: July 29, 2018, 07:36 PM »
@Sparktrician - it sounds like his 60 amp breaker that used to feed a hot tub is in between his main panel and the basement. If the wires feeding that 60 amp breaker are good can he run the feed for his new sub panel from there to the basement, effectively making the existing 60 amp breaker the main for his new sub panel even though it is 20’ away?

My interpretation is that he has a 60 amp breaker in his main panel feeding a subpanel that used to feed a hot tub.  The wiring that fed the subpanel can be pulled back and the subpanel relocated to the basement, provided that there's no damage to the existing wire.  Most importantly, anything he does must be completely in compliance with local electrical code.  In any case, the AHJ has the final say. 
- Willy -

 "Remember, a chip on the shoulder is a sure sign of wood higher up." - Brigham Young

Offline tealfixie

  • Posts: 10
Re: Repurposing a hot tub circuit breaker
« Reply #4 on: July 29, 2018, 10:30 PM »
That's correct, there's a 60 amp breaker going out to the spa panel. I didn't get a chance to open that panel up today due to such beautiful weather  [big grin]. I am going to assume there's some kind of GFCI breaker out there as well. I was thinking about just running a few auxiliary circuits from that panel but I'm afraid that there might not be enough space in that panel to run 3-4 extra circuits.

Is it out of the question to wire a sub panel to the sub panel? I'd like to just connect straight to the spa panel since I would have a shorter wire run. That's kind of what I'm researching so I can have an informed discussion with the electrician.

@Sparktrician - it sounds like his 60 amp breaker that used to feed a hot tub is in between his main panel and the basement. If the wires feeding that 60 amp breaker are good can he run the feed for his new sub panel from there to the basement, effectively making the existing 60 amp breaker the main for his new sub panel even though it is 20’ away?

My interpretation is that he has a 60 amp breaker in his main panel feeding a subpanel that used to feed a hot tub.  The wiring that fed the subpanel can be pulled back and the subpanel relocated to the basement, provided that there's no damage to the existing wire.  Most importantly, anything he does must be completely in compliance with local electrical code.  In any case, the AHJ has the final say. 

Offline Mario Turcot

  • Posts: 828
Re: Repurposing a hot tub circuit breaker
« Reply #5 on: July 30, 2018, 07:23 AM »
If ever you have to change the wire, go aluminium. 3 times cheaper

Mario

Offline Sparktrician

  • Posts: 3746
Re: Repurposing a hot tub circuit breaker
« Reply #6 on: July 30, 2018, 08:11 AM »
If ever you have to change the wire, go aluminium. 3 times cheaper

Careful with that!  Aluminum is less expensive, but it comes with a price.  One must be certain to use AL-OX to protect any copper-to-aluminum joints to prevent corrosion.  Given that this could be a pull-back of existing copper, I'd far prefer to reuse the copper if it's in good condition.  Actually, I'd prefer to use copper in any case. 
- Willy -

 "Remember, a chip on the shoulder is a sure sign of wood higher up." - Brigham Young

Offline Mario Turcot

  • Posts: 828
Re: Repurposing a hot tub circuit breaker
« Reply #7 on: July 30, 2018, 09:37 AM »
Sorry, I read economical and auto-switch to alu  [scared]

and yes you have to use nalox grease on all connectors. Another thing to keep in mind when installing a new panel and especially with alu wires is to re-visit your connection after 12 months. Shut down the main power and tighten the connectors screws. It's unbelievable what tiny vibrations can do to your connections. I use to do annual shut down on facilities and those maintenance fix a lot of problems like flickering lights.
Mario

Offline DeformedTree

  • Posts: 442
Re: Repurposing a hot tub circuit breaker
« Reply #8 on: July 30, 2018, 10:53 PM »
If you are using the freed up space in your panel to run a new feed, then this is easy.  Run a new line between the 2, install a new panel, get a 100A main breaker panel with 20 spaces.  Run new wire back to the old panel, install a 100A breaker there to feed it. Main breaker panels are a much better option (and oddly cheaper) than a main lug style.  While the down stream breaker is redundant safety wise, it means you can kill the works right there in your space, verses having to run back to the main panel to shut things down.  Depending on access between the 2, the ideal is to run a conduit between the 2, run TWHN wire between the 2.  This is the best approach.  If you have to do some tricky routing and such, then you will have to go to service cable which can be run between the 2, I think most of these are aluminum, which isn't great, but it gets the job done.  I ran my house for years like this with the new service feeding the old panel which became a sub panel before it was fully replaced by complete house re-wire.  I don't want aluminum wiring for anything, and really the cost difference isn't much.

The 20 breaker panel is more than you should ever need, but they don't hurt. Also if you want to start smuggling in 220V tools, you will need 2 slots for each tool as you can't have 220 Branch circuits, so having the expansion room right there would be ideal.

Now if re-running the wire is an issue and what you really want to do is re-route the 60Amp feed to a panel at the end of the run, that can be done. But there are catches.

1) Since you can only support 60A, you can't use a main breaker sub panel they only make them down to 100A, so you will have to use a main lug panel, thus you loose the local shut off, but everything will be code conforming. Technically there is probably nothing wrong feeding a 100A panel with a 60A feed that has a 60A breaker on the supply end, but it would be confusing because it's not really 100A panel at that point. So pretty sure that would be a code violation, but not because there is any kind of safety risk.

2) You have to see what the hot tub feed was.  Was it 3 wire or 4 wire feed.  If the hot tub was a straight 220 setup, and not a 220/110 setup you won't have a neutral, which means you can't use that feed to supply a sub panel.

2b), if you only have 6-2 wiring, not 6-3 wiring, as mention above, you are missing a neutral.  If you don't require 220V, you could make it a 110V only sub panel with this feed.  I'm not sure if they still make these or if you would basically just have to use a main lug panel and not wire 1 side of it.  I wouldn't do this, it's sketchy.  But I do think you can find 110 main lug mini panels with like 6 breaker slots.


Your electrician will know, but if you haven't wired a sub panel, you need to remember to un-bond the neutral bar from the ground bar in the panel.  Those only bond in one place in your house, usually the main panel, but can also be in an external disconnect switch.  Where this will matter to you is if you ever wire up a plug from this new panel, you have to be sure to put your neutral to neutral bar and ground to ground bar and not have them mixed like you will typically see in a main service panel. It's best practice to always keep them separate even when the jumper is in place, but in a sub panel you must keep seperate.