DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Electrical (http://www.diychatroom.com/f18/)
-   -   What size Wire for 70 Amp at 107 Feet (http://www.diychatroom.com/f18/what-size-wire-70-amp-107-feet-151735/)

kenb1023 07-27-2012 04:26 PM

What size Wire for 70 Amp at 107 Feet
 
I am running power to an out building for a hot tub. The breaker is 70A the distance from Main to sub is about 107 ft. Conduit is under ground 1 1/4" PVC EMT. What size wire should this be?

kenb1023 07-27-2012 04:26 PM

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 donít 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.

stickboy1375 07-27-2012 04:32 PM

Quote:

Originally Posted by kenb1023 (Post 975651)
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.

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.

Speedy Petey 07-27-2012 04:42 PM

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"?

stickboy1375 07-27-2012 04:42 PM

Quote:

Originally Posted by Speedy Petey (Post 975669)
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:

kenb1023 07-27-2012 04:45 PM

Quote:

Originally Posted by stickboy1375 (Post 975658)
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?

stickboy1375 07-27-2012 04:47 PM

Quote:

Originally Posted by kenb1023 (Post 975673)
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.

kenb1023 07-27-2012 04:48 PM

Quote:

Originally Posted by stickboy1375 (Post 975671)
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

stickboy1375 07-27-2012 04:51 PM

Quote:

Originally Posted by kenb1023 (Post 975675)
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....

Speedy Petey 07-27-2012 04:55 PM

Quote:

Originally Posted by kenb1023 (Post 975675)
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:

kenb1023 07-27-2012 04:58 PM

Quote:

Originally Posted by Speedy Petey (Post 975683)
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.

stickboy1375 07-27-2012 04:59 PM

Quote:

Originally Posted by kenb1023 (Post 975685)
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)

kenb1023 07-27-2012 05:07 PM

Quote:

Originally Posted by stickboy1375 (Post 975686)
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.

stickboy1375 07-27-2012 05:09 PM

Quote:

Originally Posted by kenb1023 (Post 975693)
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...

kenb1023 07-27-2012 05:11 PM

Quote:

Originally Posted by stickboy1375 (Post 975694)
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.


All times are GMT -5. The time now is 11:43 PM.


Copyright © 2003-2014 Escalate Media LP. All Rights Reserved