Hot Tub Connections and AL Wire

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Old 04-27-20, 10:39 AM
J
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Hot Tub Connections and AL Wire

I am adding a hot tub and have a question on AL wire. The requirements state I need a 240V 50 amp circuit, but also state to use Copper Wire only. I have an existing 240V 50 amp circuit that was used for my oven (switched to gas so no longer being used). I would love to be able to repurpose this circuit for the hot tub.

My question is, can I tap into this circuit where it currently ends (basically in the crawl space), via a disconnect or junction box, and then run copper from there out to the hot tub? Is the copper requirement just because of the outdoor nature of the wiring (in my case everything outside would be copper, AL would only be under the house). Or is there more to it than that? Anything else I need to be aware of?

Thanks.
 
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Old 04-27-20, 11:24 AM
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Aluminum and damp areas make for problem connections. Done correctly there is no problem however when not done correctly the control boards fry and the manufacturers get blamed incorrectly.

You need a disconnect within sight of the hot tub.
You can splice aluminum to copper using the correct methods that don't allow the two to touch.
Any ground wiring run outside must be insulated.... which eliminates using cable outdoors.

You also need to confirm if your tub is 120/240v or 240v only.
120/240v requires four wires. Two hots, neutral and ground.
240v requires three wires. Two hots and a ground.
 
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Old 04-27-20, 11:33 AM
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Is your hot tub right near kitchen? Depending on how much you have to extend, it might be better to just pull new cable from the panel. You can use the same breaker that was feeding old oven.

As PJmax said, you can splice aluminum wire to copper wiith proper connectors, but if your tub requires 120/240V, then you probably will need to pull new cable. Your old oven wire is most likely SER cable with uninsulated ground/neutral wire.
 
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Old 04-27-20, 11:42 AM
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Was definitely planning on running copper to a GFCI disconnect outside for the hot tub to wire into.

Is the insulated neutral/ground a requirement from the box to the disconnect for the Hot Tub, or just a requirement for any wiring outside the house?
 
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Old 04-27-20, 02:49 PM
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Insulated neutral wire is required only if it is 120/240V system. This means your hot tub will utilize both 120V and 240V. Uninsulated neutral wire on SER cable was used as ground wire in 3 wire system, but this is no longer allowed.
If your hot tub only uses 240V, then you can use this uninsulated wire as ground.

For splicing aluminum wire to copper, you will have to use polaris connectors or dual rated split bolt and tape the splice.
 
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Old 04-27-20, 03:11 PM
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I took a closer look at the wire in the panel box. There is an insulated neutral, but uninsulated ground.

The additional complication is that the wire currently comes through the wall and terminates in a plug ( I added that when the gas stove was put in incase someone wanted to go back to electric). I had thought the wire came through the crawlspace and up from the floor but it doesn't. That being the case, it may be easier to run a new dedicated line.
 
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Old 04-27-20, 03:12 PM
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Any grounding conductor outside must be insulated.
 
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Old 04-27-20, 03:42 PM
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There is an insulated neutral, but uninsulated ground.
That would mean you have 4 wire system and you can use that cable for 120/240V as well.

Only issue is often it is easier to pull new cable as you found out already. It is hard to make a splice on thick wire,especially when splicing aluminum to copper. Will need pretty large junction box as well.
 
 

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