Planning the elctrical hook up...

[Fcat]

I'm in Stafford VA and running a 6/3 wire from the breaker box, through the exterior wall and along the house foundation outside to the emergency cut off box, am i correct in aluminum 6/3 SER cable is in compliance with code etc. As per this: https://www.wireandcableyourway.com/6-3-6-ground-ser-aluminum-building-wire.html?gclid=CjwKCAjw2NvLBRAjEiwAF98GMfpjbdXBAXFles7FyV4iCCfLVuEXnZK_u2kdCNO5RT4qnbeLbikwmRoCGXgQAvD_BwE


I'll then be using the correct copper gauge and wire from the cut off box to the tub.

[bud16415]

I ran copper #6 and would recommend copper, but I’m 99% sure alum. Will be to code. There is a cost savings to alum. But it wouldn’t be worth it for me with the potential problems. I have alum. Only as my house service from the road in. That was done by the pros and they know how to bond it correctly etc. Alum. Also has to be de-rated for current rating of your tub. If your tub is 50a you will be ok with what you selected. I could have used #8 copper and been fine but like the overprotection so I went with #6.

Check with your local builders to be sure what code is where you live.       

[Fcat]

Thanks for the info, yes the tub is 50amp, so am i correct in that if i did use copper i could use #8 ? there's a vast difference in price and if #8 is rated for use with 50amps then id rather use that, again, thanks for the help.

[Fcat]

Just looked and it looks as though 38 is only rated to 40amps

[Clarkp]

You might want to check with the tub manufacturer and make sure they will honor their warranty with an aluminum hookup.  Better Nate than lever.

[bud16415]

It depends on the length of the run the material in the wire the voltage and the wire gage. You will always get a voltage drop but you want to keep it I was taught under 2% for the best outcome.

Here is a calculator you can use and play with your numbers. Once you have the numbers in select a small wire size and you will see it will give you a message that it won’t support that small a wire.

There are dozens of calculators on line this is just the first one that popped up. 

http://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=2.061&voltage=240&phase=ac&noofconductor=1&distance=100&distanceunit=feet&amperes=50&x=49&y=14

[bud16415]

I just looked up percentage voltage drop. 2% as I mentioned is a very good size conductor. Actually anything up to 5% is ok.
So based on that and your wire length 3 or 4% would be in the #8 range. Keep in mind that 50 amp rating is also a max number that’s all pumps and heater full on. So the tub might be slightly inefficient at 4% compared to 2% but normally the load might be only 20a when the tub is just heating. When you run 20a at the wire sizes you will see the efficiency gets much better.

[BullFrogSpasMN]

my electrician never uses it....not worth the few dollars in savings for a simple household hot tub wire job is what he always told me, also said it has a bad stigma attached to it because most of the un-licensed scabs off Craigslist use it so their quotes can come in as cheap as possible.

[Fcat]

Thanks all, I'll take some measurements, crunch some numbers and have a look around

[bud16415]

Sounds like a plan.