Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 09-19-2010, 10:41 PM   #1
Newbie
 
Join Date: Sep 2010
Posts: 8
Share |
Default

Spa Subpanel


I am wiring a 50amp sub-panel for a new hot-tub installation. My main panel is in the garage and the sub-panel will be located on the wall of my house, approximately 115 feet away. My main panel is 200amp and has lots of room in it in terms of available capacity.

I calculated that I can use #6 wire to feed the sub-panel. The sub-panel requires 4 wires (including the ground). Approximately 30 feet of the run, from the garage to the crawlspace is outdoors. The remainder of the run is indoors in the crawlspace.

I was going to run 1" plastic conduit to accommodate 3 #6 THHN and 1 #8 THHN (ground) from the main panel, out the garage along the house and into the crawl space (none of this would be underground). For convenience and economic reasons, after entering the crawlspace, I was going to put a junction box in and switch to 6/3 Romex. The Romex would run through the crawl (approx 85 feet) up the inside of the wall cavity and out to the sub-panel which will be mounted on the outside of the house (same wall cavity). Is this ok to do, or do I need to run conduit through the entire crawl?

The sub-panel has a 30amp GFCI breaker and a 20amp GFCI breaker. The sub-panel comes with the spa (Hot Spring) and the spa manual indicates that #10 THWN (inside conduit) should be run from the 30 amp breaker and #12 THWN (inside conduit) should be run from the 20 amp breaker. This portion of the run between the sub-panel and spa will be mostly underground (buried 18") and is approximately 30 feet.

I would appreciate any suggestions and input.

Thanks


Last edited by rsc92; 09-19-2010 at 10:44 PM.
rsc92 is offline   Reply With Quote
Old 09-19-2010, 11:19 PM   #2
Member
 
Join Date: Feb 2010
Location: MI's Western UP
Posts: 599
Default

Spa Subpanel


you'll need to step up a size for that length of run. maybe up a couple sizes to switch to Al to possibly save some coin.

you might also want to step up the the power capacity of the sub incase you want to run other things from it in the future.

I'm not crazy about the mid run splice.

forresth is offline   Reply With Quote
Old 09-20-2010, 12:57 AM   #3
DIY'er
 
jamiedolan's Avatar
 
Join Date: Sep 2008
Location: Neenah, Wisconsin, USA
Posts: 2,032
Blog Entries: 2
Default

Spa Subpanel


I dislike the splice idea also. Can you use ENT inside to make it easier and pull thxn the whole way?

Jamie
jamiedolan is offline   Reply With Quote
Old 09-20-2010, 01:07 AM   #4
" Euro " electrician
 
frenchelectrican's Avatar
 
Join Date: Apr 2006
Location: WI & France { in France for now }
Posts: 5,369
Default

Spa Subpanel


It will be alot easier to just run the whole thing in conduit so you can avoid a mid run splices and much quicker this way.

Run with 16mm { # 6 AWG } indivual conductors all the way and I figures with that distance you will be fine with 16mm.

However I just have one condersation it do come up the spa subpanel is that part of the spa you are getting or that is a seperated item ??

The reason why I ask you on this part due it may crossover on the code due it may become a feeder then it will change the codes a bit.

Merci.
Marc
frenchelectrican is offline   Reply With Quote
Old 09-20-2010, 05:47 AM   #5
Newbie
 
Join Date: Sep 2010
Posts: 8
Default

Spa Subpanel


Is there a safety or voltage loss reason for not splicing into the Romex once I enter my crawl space. I just think running the conduit and 3 #6 and 1 #8 THHN in the conduit for a 100+ foot run is going to be a real difficult task. In addition, the THHN will cost about @ $130 more and I will need to buy 100 more feet of conduit.

The sub-panel comes from the spa manufacturer. I have no other electric needs at that area, the 50amp will be sufficient.

If I do the whole run in conduit with THHN, would you use 1" or 3/4". Is the #8 for the ground overkill or should I run 3 #6 and 1 #10?

Thoughts.

BTW - I am in New York

Last edited by rsc92; 09-20-2010 at 07:10 AM.
rsc92 is offline   Reply With Quote
Old 09-20-2010, 09:45 AM   #6
Just call me Andrew
 
Join Date: Mar 2009
Location: Albany, NY
Posts: 2,252
Default

Spa Subpanel


First off - I'd go up to 1.5" conduit, will make the pull easier. Also, as you assemble the conduit. you can put a piece of rope as you glue the pieces. Then you can tie the 4 wires to the rope and pull through. Do not run the wire as you glue the conduit together, the PVC cement will destroy the wire's insulation.

Also get a jar of wire lube and have a buddy pull on one end and "lube it up" every few seconds.
__________________
Andrew

secutanudu is offline   Reply With Quote
Old 09-20-2010, 10:09 AM   #7
UAW SKILLED TRADES
 
Stubbie's Avatar
 
Join Date: Jan 2007
Location: Kansas
Posts: 4,980
Default

Spa Subpanel


Rsc92

Part of the problem with answering your question is it appears you have not visited with your local codes department to determine if they are going to require conduit all the way from your main panel to the spa panel. National code requires that feeders (not a branch circuit) serving hot tub / Spa panels with circuit breakers be installed in an approved conduit.

The grey area is that your spa panel came with your spa package and this may allow you to consider the wiring run as a branch circuit (probably No). IMO I would make the effort to run conduit so that maximum safety and protection is offered to the wires. Crawl spaces can be very damp and moisture prone...rodent damage..etc. You especially want maximum protection for the equipment ground wire as it is there for human safety in the event of a ground fault.

I would suggest you contact the manufacturer or the local codes department for a determination whether feeder or branch circuit. Then you will know if you are code compliant ... local codes department would be your better resource.

Also there is nothing wrong with having a #8 egc vs a number #10 egc. You would be code compliant with insulated green #10 awg copper.
__________________
" One nice thing about the NEC articles ... you have lots of choices"

Stubbie

Last edited by Stubbie; 09-20-2010 at 10:15 AM.
Stubbie is online now   Reply With Quote
Old 09-20-2010, 10:26 AM   #8
Newbie
 
Join Date: Sep 2010
Posts: 8
Default

Spa Subpanel


Quote:
Originally Posted by Stubbie View Post
Rsc92

Part of the problem with answering your question is it appears you have not visited with your local codes department to determine if they are going to require conduit all the way from your main panel to the spa panel. National code requires that feeders (not a branch circuit) serving hot tub / Spa panels with circuit breakers be installed in an approved conduit.

The grey area is that your spa panel came with your spa package and this may allow you to consider the wiring run as a branch circuit (probably No). IMO I would make the effort to run conduit so that maximum safety and protection is offered to the wires. Crawl spaces can be very damp and moisture prone...rodent damage..etc. You especially want maximum protection for the equipment ground wire as it is there for human safety in the event of a ground fault.

I would suggest you contact the manufacturer or the local codes department for a determination whether feeder or branch circuit. Then you will know if you are code compliant ... local codes department would be your better resource.

Also there is nothing wrong with having a #8 egc vs a number #10 egc. You would be code compliant with insulated green #10 awg copper.

Stubbie,

Thank you for your informative response. I will run THHN in pvc conduit for the entire run. The total run from the main panel to the spa supplied sub-panel is approximately 125 feet. The manual supplied by the spa company indicates that for runs 100 feet or less, #8 wire can be used with a #10 insulated ground. Based on my calculations, #6 THHN wire will be a better option based on the length of the run and the fact that I want to minimize voltage loss to 3% or less. Would I still be code compliant with the #10 THHN insulated green ground or should I upsize that too to #8 THHN green?

Also, another poster indicated that they would use 1.25 inch pvc. Is that overkill? I was planning on 1". What are your thoughts? Is there a trick to pulling four large cables for a 100+ foot run? Would the rope suggestion work or is it better to buy a long fish tape?

Thanks
rsc92 is offline   Reply With Quote
Old 09-20-2010, 10:32 AM   #9
Just call me Andrew
 
Join Date: Mar 2009
Location: Albany, NY
Posts: 2,252
Default

Spa Subpanel


Quote:
Originally Posted by rsc92 View Post
Also, another poster indicated that they would use 1.25 inch pvc. Is that overkill? I was planning on 1". What are your thoughts? Is there a trick to pulling four large cables for a 100+ foot run? Would the rope suggestion work or is it better to buy a long fish tape?

Thanks
I actually said 1.5" but I meant 1.25....

That's how I pulled the wires for my lamppost. That was only #12 wires, and 3 of them. Though I used a piece of string, not a rope, since the wires were much smaller. It worked really well, especially with the lubricant. Just make sure you tape the hell out of the conductors to the rope so they don't come off.

If you have any turns indoors, I'd use pull elbows instead of sweeping elbows...I don't think pull elbows can be buried, but it makes pulling wire through turns way easier.

Also, since you're in a freezing climate, think about putting an expansion joint in your conduit to prevent cracking, more info on those here:
http://www.carlon.com/Installation_T...IT-ISEXPJT.pdf
__________________
Andrew

secutanudu is offline   Reply With Quote
Old 09-20-2010, 10:47 AM   #10
" Euro " electrician
 
frenchelectrican's Avatar
 
Join Date: Apr 2006
Location: WI & France { in France for now }
Posts: 5,369
Default

Spa Subpanel


Let me add couple more comment above what other poster been saying so far,

First thing when you run the conduit you will have to make sure you do not go over 360 of bend totals so like example total of 4 X 90 ells or any other combations of ells.

If you go above that then put a pull box or LB one of the two will meet this requirement real easy.

Speaking of grounding conductor { Green wire } you should be code compaint with 6mm {#10 AWG } however IMO if you upsized the conductor then you have to upgrade the grounding conductor to 10mm { # 8 AWG } the main key issue is for fault issue and bonding issue.

1 inch conduit will work fine for this useage if only have two 90 ells otherwise bump up one size larger which it is will be 1.25 inch.

You can use either pulling rope or fishtape to pull the conductors in the conduit make sure you use wire lube with pulling in the conductor it will make it easier to pull it in the conduit.

If any other question just holler one of us will help ya.

Merci,
Marc
frenchelectrican is offline   Reply With Quote
Old 09-20-2010, 10:56 AM   #11
Newbie
 
Join Date: Sep 2010
Posts: 8
Default

Spa Subpanel


It is a pretty straight run. I am thinking two sweeping elbows and two traditional elbows. I may need to bend some of the pvc a bit, but that should do it (from main to sub).

In terms of the wiring from the sub to the spa. Is the #10 and #12 recommended by the spa manufacturer sufficient? They want it run in 3/4 in conduit from the sub to the spa. It is gonig to be 3 #10 and 3 #12 (including the ground). This run is relatively straight and will be no more than 30 or 35 feet. The conduit must be buried 18" to comply with local code requirements.

Thanks
rsc92 is offline   Reply With Quote
Old 09-20-2010, 11:18 AM   #12
" Euro " electrician
 
frenchelectrican's Avatar
 
Join Date: Apr 2006
Location: WI & France { in France for now }
Posts: 5,369
Default

Spa Subpanel


Quote:
Originally Posted by rsc92 View Post
It is a pretty straight run. I am thinking two sweeping elbows and two traditional elbows. I may need to bend some of the pvc a bit, but that should do it (from main to sub).
Ok that will be not a issue at all.

Quote:
In terms of the wiring from the sub to the spa. Is the #10 and #12 recommended by the spa manufacturer sufficient? They want it run in 3/4 in conduit from the sub to the spa. It is gonig to be 3 #10 and 3 #12 (including the ground). This run is relatively straight and will be no more than 30 or 35 feet. The conduit must be buried 18" to comply with local code requirements.

Thanks
Now that part may raise a red flag on this one due the distance of subpanel to the spa I know most spa I have deal I put the subpanel no more than 10 feet away or not less than 5 feet away for two fold reason one is you can able shut off the spa real quick second thing it will meet the NEC code.

It may sound silly to run two conduits from subpanel to the spa you can run one inch conduit from subpanel to spa which I have done it from time to time.

So you can have both 4.0's and 6.0's in there without issue but you can use single grounding conductor instead of two but it will sized to 6.0mm or larger.

Merci.
Marc
frenchelectrican is offline   Reply With Quote
Old 09-20-2010, 12:10 PM   #13
Member
 
Join Date: Feb 2010
Location: MI's Western UP
Posts: 599
Default

Spa Subpanel


Quote:
Originally Posted by frenchelectrican View Post

Speaking of grounding conductor { Green wire } you should be code compaint with 6mm {#10 AWG } however IMO if you upsized the conductor then you have to upgrade the grounding conductor to 10mm { # 8 AWG } the main key issue is for fault issue and bonding issue.
actually, I think #6 or #8 may be code for bonding.

Pools (and preumably spas) have a whole seperate mess of codes. for example, now, the water itself must be bonded. I'd hope the spa mfg would have all that crap taken care of and be part of the instlation instructions, but its something you have to consider.
forresth is offline   Reply With Quote
Old 09-20-2010, 02:35 PM   #14
UAW SKILLED TRADES
 
Stubbie's Avatar
 
Join Date: Jan 2007
Location: Kansas
Posts: 4,980
Default

Spa Subpanel


Quote:
Thank you for your informative response. I will run THHN in pvc conduit for the entire run. The total run from the main panel to the spa supplied sub-panel is approximately 125 feet. The manual supplied by the spa company indicates that for runs 100 feet or less, #8 wire can be used with a #10 insulated ground. Based on my calculations, #6 THHN wire will be a better option based on the length of the run and the fact that I want to minimize voltage loss to 3% or less. Would I still be code compliant with the #10 THHN insulated green ground or should I upsize that too to #8 THHN green?
The upsizing of the equipment ground is a rather confusing issue and I really don't think it would benefit to explain it. The idea is that the larger the conductor the more available fault current .. you do not want the egc to be undersized causing so much impedance that it delays the opening of the circuit breaker or doesn't allow it to open due to voltage drop on the egc.
So I would run #8 egc as this will be more efficient in delivering a high fault current to open the cb faster. With spas and pools it is better to think above code minimums for the safety of friends and family. You will sleep better.

#6 copper thhn/thwn for the hot conductors and neutral is fine.

Be sure to see if there is a installation guide line with your local codes department and set up an inspection by them so that you can be sure your installation meets code. It is a simple deal with minimal cost and again will let you sleep better.

There is more to this that just running wire to the hot tub and that will be dictated by the year of the national code cycle your jurisdiction enforces.



Quote:
Also, another poster indicated that they would use 1.25 inch pvc. Is that overkill? I was planning on 1". What are your thoughts? Is there a trick to pulling four large cables for a 100+ foot run? Would the rope suggestion work or is it better to buy a long fish tape?
1 " schedule 40 pvc will allow 6 wires that are 6 awg so I see no reason to upsize to 1.25 pipe for three #6 and one #8.

The spa panel if used as your maintenance disconnect is required to be no closer than 5 feet to the spa and 'within sight of the spa'. Within sight means 50 feet. So I do not see a problem with its location being 30 feet as long as you can see it from the spa. It is not an emergency disconnect.

Again see if you can get the installation guide lines from local jurisdiction this will save you a lot of guess work.
__________________
" One nice thing about the NEC articles ... you have lots of choices"

Stubbie

Last edited by Stubbie; 09-20-2010 at 02:43 PM.
Stubbie is online now   Reply With Quote
Old 09-20-2010, 03:30 PM   #15
Newbie
 
Join Date: Sep 2010
Posts: 8
Default

Spa Subpanel


Again, thanks for the response. In order to get the local requirements, would I contact the building department of my municipality or Fire Underwriters?

rsc92 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Grounding a Subpanel Craigman Electrical 25 12-07-2009 07:25 PM
Problems with Square D Subpanel bltglt507 Electrical 16 12-04-2009 08:44 PM
A few slightly different questions on subpanel wiring. Chris Dopp Electrical 8 06-26-2009 09:45 PM
Another subpanel question:) primal65 Electrical 15 06-22-2008 09:43 AM
Reverse Polarity at the Subpanel adm060306 Electrical 14 07-09-2007 12:58 PM




Top of Page | View New Posts

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