hot tub wiring questions

Reply

  #1  
Old 06-24-10, 07:13 AM
D
Member
Thread Starter
Join Date: May 2006
Posts: 8
Received 0 Votes on 0 Posts
hot tub wiring questions

This is in regards to the following post: http://forum.doityourself.com/electr...-tub-help.html
Originally Posted by ibpooks View Post
SubNextToMain-- I'm not even sure why this panel is here at all. It should probably be eliminated entirely. If it's left it at least needs:

1) Green ground needs to be added to incoming conduit and terminated on ground bar to the right.

2) Ground from top also needs to go to right ground bar.

3) Bonding screw below neutral bar should be removed.

4) White neutral coming in from top needs to go to the center neutral terminal on the GFCI breaker.
I'm jumping in here since I happen to also be installing a used hot tub although there was one in the house under the previous owner, and I am confident that the main breaker panel is wired correctly. My points refer to the SubNextToMain box. This is where the GFCI will be mounted and isn't it true that it has to be 5 to 10 feet from the hot tub? So that GFCI needs to be moved to an outside location where it can be accessed. The box that I am using does not have a separate ground bar to the right as the OP has. The ground bar is mounted on the left where the white pigtail from the GFCI is going. I was under the impression that you were only supposed to wire white and ground to the same bar in the main breaker. Couple of questions...Can I use the 1 ground bar that I have as a common point of connection for the pigtail and ground wires?
What the heck is the purpose of that metal rod that can rotate a bit and is mounted on the backside of the box (you can see it in the picture posted by the OP) and most of us in wiring a hot tub would be using plastic conduit so how important is it to remove this bonding screw thing? There is a ground wire that comes up through my slab that I was going to wire to the hot tub itself and of course there is the grounding stake in the front yard wired to the breaker (and one by the gas meter).

not trying to hijack, but figured the questions are very close...hope the OP has made some progress on the project.

dan
 

Last edited by danoer1; 06-24-10 at 07:45 AM. Reason: post was moved... my bad for hiacking
Sponsored Links
  #2  
Old 06-24-10, 08:47 AM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,943
Received 43 Votes on 41 Posts
Originally Posted by danoer1 View Post
isn't it true that it has to be 5 to 10 feet from the hot tub?
At residential locations, there needs to be a disconnect within line of sight of the tub but no closer than 5'. Some local codes enforce a maximum distance, national code only mentions a maximum distance for non-residential installations. It does not have to be the GFCI device; it can be a standard air conditioner style pullout. It is usually convenient to make the GFCI unit also be the disconnect because of the relatively cheap price of the GFCI spa disconnect boxes on the market.

Can I use the 1 ground bar that I have as a common point of connection for the pigtail and ground wires?
No, in a subpanel the ground and neutral must be separate. The ground bar is connected to the metal enclosure and the neutral bar floats on plastic insulators. If there is a bonding screw between the neutral bar and the case it should be removed.

There is a ground wire that comes up through my slab that I was going to wire to the hot tub itself
If this slab was specifically built for the tub, the wire from the slab is probably a bonding wire which is to equalize the potential (voltage) between the metal rebar in the concrete and the tub, so when you step out with one leg in the water and one leg on the deck you can't get shocked.

and of course there is the grounding stake in the front yard wired to the breaker (and one by the gas meter).
Assuming they're connected properly, they are a required part of the electrical service. Ground rods are mostly a lightning protection measure.
 
  #3  
Old 06-24-10, 11:26 AM
D
Member
Thread Starter
Join Date: May 2006
Posts: 8
Received 0 Votes on 0 Posts
thanks for the reply. A few questions

Here is an image of the GFCI setup I was given to use with this hot tub. There is no separate ground bar, and the small bar of the left of the photo is not grounded. Do I need to add a ground bar?

Here is what I had planned to do, although the ground is a question

I was given three lengths of 6 gauge wire. The longest is about 45 ft and is not long enough to run from my main breaker panel to the GFCI box (PVC conduit is already present). Can I "bridge" two pieces of this expensive ($2.50/ft) wire using this fusible box? Is there a better/other solution?

Thanks,

dan
 
  #4  
Old 06-24-10, 11:41 AM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,943
Received 43 Votes on 41 Posts
Originally Posted by danoer1 View Post
Do I need to add a ground bar?
Yes. The ground conductors running to the ground bar must be green insulated copper, #10 minimum (or larger if the spa manual requires it). The sliver colored strap screwed to the center back of the box can be removed and discarded -- it would never be used with a spa.

Can I "bridge" two pieces of this expensive ($2.50/ft) wire...Is there a better/other solution?
You could, but I don't recommend it. Every splice is a potential failure point, plus you need extra conduit fittings, splice blocks, etc to add the unnecessary box. My recommendation is to buy the correct lengths of THWN wires. What is the electrical requirement of the tub and what is the breaker size? You may be okay with #8.
 
  #5  
Old 06-24-10, 01:09 PM
D
Member
Thread Starter
Join Date: May 2006
Posts: 8
Received 0 Votes on 0 Posts
thanks for the response...

I am using 6 gauge stranded copper wire that is in a Romex sheath. 3 stranded wires plus a solid ground. It is a 240 V spa. Now the ground wire in the Romex cable I have is not a "green" insulated ground, but a bare copper that has the brown paper sheathing around. No good? This is all from the previous owner of the spa, so I was thinking of using what he had given me. I'll add a ground bar (seems like there are screw holes in the back of the box that are covered with those white paper circles)

The breaker size I have is 60 amp. The time and expense of cutting open the old conduit and putting in some type of box would offset the $160 cost of the new wiring...seems a shame to not use what he gave me.

dan
 
  #6  
Old 06-24-10, 01:46 PM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,943
Received 43 Votes on 41 Posts
Originally Posted by danoer1 View Post
Now the ground wire in the Romex cable I have is not a "green" insulated ground, but a bare copper that has the brown paper sheathing around. No good?
This cable is not legal for use outdoors or with a spa. The previous installation was obviously not done to code or inspected.

The breaker size I have is 60 amp.
Do you know what the tub actually requires either from a manual or nameplate in the wiring compartment of the tub?

seems a shame to not use what he gave me
Copper pays a decent price at a metal recycler.
 
  #7  
Old 06-24-10, 02:15 PM
D
Member
Thread Starter
Join Date: May 2006
Posts: 8
Received 0 Votes on 0 Posts
so this cable is not legal for a spa?

dan
 
  #8  
Old 06-24-10, 02:22 PM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,943
Received 43 Votes on 41 Posts
It is legal only for the interior portion of a spa circuit in a single-family residence. It is not allowed for the outdoors or underground portion of the circuit. Usually if we use that type of cable (NM-B) indoors, we will go directly into the back of a GFCI disconnect box or subpanel on the exterior wall. From that box to the spa, it must be conduit with the insulated green ground.
 
  #9  
Old 06-24-10, 02:48 PM
D
Member
Thread Starter
Join Date: May 2006
Posts: 8
Received 0 Votes on 0 Posts
thanks for that clarification. So I am good to use it for the interior run, but am stuck with too short of a length. The requirements for the spa are 240 V 32 amp rating with 3 wire + ground branch circuit with protection to 40 amp and 6 awg wire. I would still like to use what I have in the interior section of the house, but just need to figure out a way to appropriately join the 6 awg wire lengths I have to reach the GFCI mounted on the outside of the house by the spa. Then buy the right length of THWN wire to reach to the spa itself.
 
  #10  
Old 06-24-10, 02:58 PM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,943
Received 43 Votes on 41 Posts
Originally Posted by danoer1 View Post
The requirements for the spa are 240 V 32 amp rating with 3 wire + ground branch circuit with protection to 40 amp and 6 awg wire.
Normally you could use #8 with a 40A load, but if the manufacturer requires #6, then #6 it is. The breaker in the main panel feeding the spa should be a double-pole 40A. The GFCI breaker should ideally also be a 40A, but the existing 60A would technically be allowed if the upstream breaker is 40A.

I would still like to use what I have in the interior section of the house, but just need to figure out a way to appropriately join the 6 awg wire lengths I have to reach the GFCI mounted on the outside of the house by the spa.
If the cable runs through an accessible path like a basement ceiling or attic, you can simply install a large junction box like 4-11/16" or 6" square with a flat cover and continue with a new piece of #6-3g cable like you already have. The box will need 3/4" knock outs to accommodate the large cable clamps. In the box, the #6 copper can be joined with large blue wirenuts. I think they're the largest size made by Ideal/Buchanan.

Then buy the right length of THWN wire to reach to the spa itself.
I recommend you install the conduit first, fish a rope or flexible tape through and get a solid measurement from that before having wire cut. The last 5' of the conduit going into the tub itself may be liquidtight flexible, the rest should be rigid PVC. Burial depth is 24" if it goes underground.
 
  #11  
Old 06-24-10, 03:29 PM
D
Member
Thread Starter
Join Date: May 2006
Posts: 8
Received 0 Votes on 0 Posts
thanks again for all your time with the posts.

so the breaker I have is a double pole 60 amp one, and the GFCI is a 50 amp. Am I ok with that?

The large 6" junction box is what I was thinking...just wasn't sure it was up to code. It would be completely accessible in the basement. I have not seen wire nuts big enough for 6 awg, but will track them down. Does this have to be a PVC box? If it is metal then I'd need to ground it as well, no?

The outside conduit is already there, buried under the slab. It is 1" grey PVC conduit. I'll run some flex tape through it to get a length before I buy the THWN wire

Is it only the last 5 ft that can be liquidtight flexible? My conduit is coming up through the slab on the opposite side of where the tub has its electrical conduit opening. I suppose I could drill a new opening, but was thinking of just running the flex conduit around to the correct side of the tub. Of course we could rotate the tub...that just puts the controls on an awkward side.

thanks again.

dan
 
  #12  
Old 06-25-10, 09:18 AM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,943
Received 43 Votes on 41 Posts
Originally Posted by danoer1 View Post
so the breaker I have is a double pole 60 amp one, and the GFCI is a 50 amp. Am I ok with that?
No. The tub specs state 40A protection so at least one of the those breakers needs to be 40A.

Does this have to be a PVC box? If it is metal then I'd need to ground it as well, no?
It can be metal. If metal, the grounds must also connect to the box with a green ground screw.

Is it only the last 5 ft that can be liquidtight flexible?
That's all the code allows. Any deviation would have to be approved by the inspector. I have had some tubs where the control panel/wiring compartment location made the 5' really impossible.
 
Reply
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


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: