# What size Wire for 70 Amp at 107 Feet



## kenb1023 (Jul 27, 2012)

More detail

I am having a hot tub house put in. The structure is about 80 feet from the house with a 100 Amp Sub Panel with one 50 Amp circuit for the hot tub, one 20 amp circuit for 4 120vac outlets and one 15 amp circuit for interior and exterior lighting. The contractor doing the work is trying to tell me it is Ok to use #8 wire for the common on a 107 foot run fed from a 70 amp breaker in the main panel in the house. Everything I have read tells me that the two hots and the common need to be #4 wire and the ground a #8. What is right for this application? Every time I build something I always over kill it to ensure safety. Now that I am paying someone else to do it I know they are going to go to the minimums for cost but I don’t want corners cut to save a few pennies.

One other item that has me concerned is the wire run is in 1 1/4" PVC conduit from the Hot tub house sub pane to the hose but then it is not in any conduit going from the house penetration to the main breaker panel. The distance is about 10 feet. Correct me if I am wrong but only Non Metallic Sheathed cable can run without conduit of some sort in the walls and attic space.

I plan to use #8 wire from the Sub panel to the hot tub in flex/water tight conduit. It is about a 10 foot run


If anyone has these answers and can let me know what code to reference I would greatly appreciate it.


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## stickboy1375 (Apr 28, 2012)

kenb1023 said:


> More detail
> 
> I am having a hot tub house put in. The structure is about 80 feet from the house with a 100 Amp Sub Panel with one 50 Amp circuit for the hot tub, one 20 amp circuit for 4 120vac outlets and one 15 amp circuit for interior and exterior lighting. The contractor doing the work is trying to tell me it is Ok to use #8 wire for the common on a 107 foot run fed from a 70 amp breaker in the main panel in the house. Everything I have read tells me that the two hots and the common need to be #4 wire and the ground a #8. What is right for this application? Every time I build something I always over kill it to ensure safety. Now that I am paying someone else to do it I know they are going to go to the minimums for cost but I don’t want corners cut to save a few pennies.
> 
> ...


Almost EVERY hot tub i've ever wired called for # 6 AWG MIN. for all the conductors...(two hots, neutral and grounding conductor) so check the hot tubs requirements first! Also, you better read article 680 for the rest of this installation and find out what code cycle of the NEC you are on... Two items I NEVER consider DIY, one being a pool, the other a hot tub.


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## Speedy Petey (Feb 1, 2004)

Are you telling us he is intending to run the THHN conductors in free air in the house to the main panel?
WHO is this "contractor"?


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## stickboy1375 (Apr 28, 2012)

Speedy Petey said:


> Are you telling us he is intending to run the THHN conductors in free air in the house to the main panel?
> WHO is this "contractor"?


Obviously not the electrical contractor.... :whistling2:


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## kenb1023 (Jul 27, 2012)

stickboy1375 said:


> Almost EVERY hot tub i've ever wired called for # 6 AWG MIN. for all the conductors...(two hots, neutral and grounding conductor) so check the hot tubs requirements first! Also, you better read article 680 for the rest of this installation and find out what code cycle of the NEC you are on... Two items I NEVER consider DIY, one being a pool, the other a hot tub.


 The instructions did not call out for a wire size. All it had was a 50A breaker was needed. When I looked up 50A feeds in my electrical book it called for #8 in conduit under 40 feet or #6 Romex cable. For this short run It won't cost much more to run #6.

Do you have any advise on the othere questions?


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## stickboy1375 (Apr 28, 2012)

kenb1023 said:


> The instructions did not call out for a wire size. All it had was a 50A breaker was needed. When I looked up 50A feeds in my electrical book it called for #8 in conduit under 40 feet or #6 Romex cable. For this short run It won't cost much more to run #6.
> 
> Do you have any advise on the othere questions?


Read article 680 of the NEC, hot tubs are involved, electrically speaking.


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## kenb1023 (Jul 27, 2012)

stickboy1375 said:


> Obviously not the electrical contractor.... :whistling2:


 The General going by the instructions of his electrican. I knew this wrong but all my electrical background is industrial/Navy


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## stickboy1375 (Apr 28, 2012)

kenb1023 said:


> The General going by the instructions of his electrican. I knew this wrong but all my electrical background is industrial/Navy


It would depend on your total load....


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## Speedy Petey (Feb 1, 2004)

kenb1023 said:


> The General going by the instructions of his electrican. I knew this wrong but all my electrical background is industrial/Navy


Why not hire a real electrician to do this job?

And you n ever answered my question about inside the house. :whistling2:


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## kenb1023 (Jul 27, 2012)

Speedy Petey said:


> Why not hire a real electrician to do this job?
> 
> And you n ever answered my question about inside the house. :whistling2:


I hired a general to do the build. I anticipated them bring in an electrician for the wiring.

As for in the house, they are not using any conduit at all. This I know is very wrong.


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## stickboy1375 (Apr 28, 2012)

kenb1023 said:


> I hored a general to to the build. I anticipated them bring in an electrican for the wireing.
> 
> As for in the house they are not using any conduit at all. This I know is very wrong.


They have to be, 680.25 (A)


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## kenb1023 (Jul 27, 2012)

stickboy1375 said:


> They have to be, 680.25 (A)


In the tub house everything is in conduit or Romex in the ceiling. In the main house (Actually the attached garage) they did not use any conduit. Just the three wires ran inside the wall cavity.


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## stickboy1375 (Apr 28, 2012)

kenb1023 said:


> In the tub house everything is in conduit or Romex in the ceiling. In the main house (Actually the attached garage) they did not use any conduit. Just the three wires ran inside the wall cavity.


3 wires? you need four, sounds very hacked...


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## kenb1023 (Jul 27, 2012)

stickboy1375 said:


> 3 wires? you need four, sounds very hacked...


 They say since the out building has it's own grounding rods the 4th is not needed.


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## stickboy1375 (Apr 28, 2012)

kenb1023 said:


> They say since the out building has it's own grounding rods the 4th is not needed.


Ugh... what code cycle are you on, and ground rods do not accomplish what a grounding conductor does... :no:

680.25 (B) requires a grounding conductor.... and you would still need ground rods...


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## electures (Dec 22, 2009)

kenb1023 said:


> They say since the out building has it's own grounding rods the 4th is not needed.


Really?


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## stickboy1375 (Apr 28, 2012)

electures said:


> Really?


Just keeps getting better, yes?  I can only imagine the other code violations.


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## kenb1023 (Jul 27, 2012)

stickboy1375 said:


> Ugh... what code cycle are you on, and ground rods do not accomplish what a grounding conductor does... :no:
> 
> 680.25 (B) requires a grounding conductor....


 This is New Mexico, I think codes just came about in the past 20 years or so.


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## electures (Dec 22, 2009)

stickboy1375 said:


> Just keeps getting better, yes?  I can only imagine the other code violations.


I wanna see the conductors in free air.


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## stickboy1375 (Apr 28, 2012)

electures said:


> I wanna see the conductors in free air.


I wanna see pictures of everything.


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## kenb1023 (Jul 27, 2012)

stickboy1375 said:


> I wanna see pictures of everything.


 I just want to make this right. I knew what they were doing was wrong but I needed validation on it. Now I have it. The trench is still open, the roof is not on yet so I am at a point the things can be fixed. It is a good thing I only put a third down for the project. I will need the leverage to get it done right. 
Thanks,


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## stickboy1375 (Apr 28, 2012)

kenb1023 said:


> I just want to make this right. I knew what they were doing was wrong but I needed validation on it. Now I have it. The trench is still open, the roof is not on yet so I am at a point the things can be fixed. It is a good thing I only put a third down for the project. I will need the leverage to get it done right.
> Thanks,


Do you have inspections in your area?


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## kenb1023 (Jul 27, 2012)

stickboy1375 said:


> Do you have inspections in your area?


 I am in the midle of no place NM. There are more cows than peopel. Getting inspectors out here is like getting DC to balance the budget


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## stickboy1375 (Apr 28, 2012)

kenb1023 said:


> I am in the midle of no place NM. There are more cows than peopel. Getting inspectors out here is like getting DC to balance the budget


Gotcha... 


Here is a great pdf file on article 680...

http://www.mikeholt.com/files/PDF/Pooldownload.pdf


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## kenb1023 (Jul 27, 2012)

stickboy1375 said:


> Gotcha...
> 
> 
> Here is a great pdf file on article 680...
> ...


Thanks, last I heard New Mexico was still under code 80 something. I wish I could remember when I was having this conversation when we moved out this way 3 years ago. Love the openness but the isolation can wear on you. We came from WI. They are very strict on a lot of things. I remember the hoops I jumped through when I built my addition. However the inspector told me I over did everything. I over built the walls roof and my electric was good for an industrial shop. 14 separate 20A circuits for the garage alone. Everything was on GFIs. The only error I made was that I did not secure the Romex cables close enough to the power panel. That was an easy fix. I did have one GFI that would trip for no reason in the laundry room every now and then. Replaced it a couple of times and had a licensed electrician look at. All he could say is that there was no reason why it would trip, may be from lightning surges.


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## stickboy1375 (Apr 28, 2012)

kenb1023 said:


> Thanks, last I heard New Mexico was still under code 80 something. I wish I could remember when I was having this conversation when we moved out this way 3 years ago. Love the openness but the isolation can wear on you. We came from WI. They are very strict on a lot of things. I remember the hoops I jumped through when I built my addition. However the inspector told me I over did everything. I over built the walls roof and my electric was good for an industrial shop. 14 separate 20A circuits for the garage alone. Everything was on GFIs. The only error I made was that I did not secure the Romex cables close enough to the power panel. That was an easy fix. I did have one GFI that would trip for no reason in the laundry room every now and then. Replaced it a couple of times and had a licensed electrician look at. All he could say is that there was no reason why it would trip, may be from lightning surges.


I believe New Mexico is on the 2011 NEC...


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## andrew79 (Mar 25, 2010)

One thing I always tell people is to ask your contractor to see the licenses of the people in his employ. Glad to see you only put a third down and very nice to see you want it done right. It's refreshing to see someone actually going above and beyond to NOT cut corners.


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## kenb1023 (Jul 27, 2012)

stickboy1375 said:


> I believe New Mexico is on the 2011 NEC...


 I know it is old because they do stuff out here that would land you in jail in WI.


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## stickboy1375 (Apr 28, 2012)

kenb1023 said:


> I know it is old because they do stuff out here that would land you in jail in WI.


It's not old, just not enforced.


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## kenb1023 (Jul 27, 2012)

andrew79 said:


> One thing I always tell people is to ask your contractor to see the licenses of the people in his employ. Glad to see you only put a third down and very nice to see you want it done right. It's refreshing to see someone actually going above and beyond to NOT cut corners.


The home is my investment in life and this is the last one I plan on living in. I will die in this house before I move. It has to be done right. I just talked to the contractor and he is going to bring the electrician out with him next week. No big rush as we are waiting on windows, patio doors and trusses to come in so we are at a standstill.


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## stickboy1375 (Apr 28, 2012)

kenb1023 said:


> The home is my investment in life and this is the last one I plan on living in. I will die in this house before I move. It has to be done right. I just talked to the contractor and he is going to bring the electrician out with him next week. No big rush as we are waiting on windows, patio doors and trusses to come in so we are at a standstill.


Article 680 can be confusing to electricians, if they don't self educate or ever get told that's not allowed, they just slip through the cracks, we are all human and make mistakes, but at some point you have to go above and beyond to self educate in the trade.


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## kenb1023 (Jul 27, 2012)

stickboy1375 said:


> Article 680 can be confusing to electricians, if they don't self educate or ever get told that's not allowed, they just slip through the cracks, we are all human and make mistakes, but at some point you have to go above and beyond to self educate in the trade.


Well I printed it off and will go over and over it. I also told the contractor that I want his electrician to sign a doc with his license number stating that it is right and to reference the codes he is going by. I find that when people have to sign a doc like this they tend to back track somewhat. 
This contractor has done other work for me in the past and has always done a good job. This is the first time I have had him do any electrical.


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## Speedy Petey (Feb 1, 2004)

kenb1023 said:


> In the main house (Actually the attached garage) they did not use any conduit. Just the three wires ran inside the wall cavity.





kenb1023 said:


> They say since the out building has it's own grounding rods the 4th is not needed.


Please, PLEASE, sh*t can these HACKS and get yourself some real electricians!!
For your own good and safety!


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