COMMUNITY FORUM

natureboy

03:43PM | 09/02/07
Member Since: 09/01/07
4 lifetime posts
Bvelectrical
Because I'm such a good husband, I bought a used hot tub for my wife, and want to install it in a detached carport which currently has no electricity. The tub is a 32A/240V, and the wife has suggested that we also make provision for a fridge, ceiling fan, microwave, uhhhh! Do I really need a load center ? If so, will a 100A do it ? If so, do I need to run a 6/3 w/ground, or more ? Total distance to the load center location from house panel box is about 55 feet.

Thanks

Billhart

08:30PM | 09/02/07
Member Since: 04/25/05
1918 lifetime posts
You are allowed only one circuit to a detached structure. In this case it would have to be a feeder to a sub-panel.

60 amps would be fine. But I would use a 100 amp panel, but feed it with a 60 amp breaker in the main panel. Doing that you can run #6 copper.

The reason that suggest the 100 amp panel is that they are commonl and have more spaces than a 60 amp panel.

Being a carport this would problem be treated as a wet area and needs an outdoor panel.

And you will need a Ground Electrode System.

Hot tubs have a number of specialized requirements. And there are a number of issues here. For example will it be treated as indoors or outdoors.

I would get a pro to do this or at least go over it step by step by with your code inspector.

natureboy

01:15AM | 09/03/07
Member Since: 09/01/07
4 lifetime posts
I did speak with the inspector when I paid for the permit fee, but at that time I was only going to be running the line to feed the tub. Good point on getting the exterior box, as this will be treated as an exterior application. I am assuming that the 60A breaker in the main box will need to be GFCI ? Now, will this 100A box need to have a main breaker, or should I just wire the feed into the bus ? And will the GFCI breaker for the tub also be considered as a "disconnect" for an exterior hut tub installation ? What would be a maximum distance from the panel for the ground rod ? Thanks.

Billhart

04:57AM | 09/03/07
Member Since: 04/25/05
1918 lifetime posts
For a separate "building" the panel would require a disconnect at the building. I am assuming that this structure would be treated the same. But that is why I am saying that it is an unusal application that has of twist.

The feeder breaker in the main panel does not need to be GFCI, but the breaker in the sub-panel that feeds the tub will be.

Also you need GFCI protects for the receptacles. However, there is an exception for large appliances that are not normally moved, IF IT WAS IN A GARAGE. Don't know if can use that exception in this case.

Fan and lights don't need GFCI protection, but there are specific requirements for distance from hot tubs (and I don't know what they are).

"And will the GFCI breaker for the tub also be considered as a "disconnect" for an exterior hut tub installation ?"

It should be. But they have have a local amendment or "practice" that they want a dedicated disconnect so that there can be no confusion about which handle to pull.

"What would be a maximum distance from the panel for the ground rod ? "

As far as I know there is no limit. I don't know if it worded as such in the code, but I believe that as close as "practical" is what is expected.

But in general "A" ground rod is not acceptable.

If you have a metalic water line to the structure and the underground portion is at least 10 ft long then it must be used as part of the ground elecrode system. But it can't be used as the only ground electrode.

Typically ground rodS are used as the auxillary electrode. Whenever a ground rod is use it must either be tested as less than 25 ohms OR 2 ground rods used that are at least 8 ft apart. And the test is specialized and usually not done.

There are other types of ground electrodes, but with an existing structure you most likely don't have a ufer (concrete encased in the footer) and theothers are not typically used in residential applications.

If the water line is not metallic underground, but is metallic in the building then that part needs to be bonded to the ground electrode system, but it is not a ground electrode.

natureboy

09:13AM | 09/03/07
Member Since: 09/01/07
4 lifetime posts
The structure is actually one of those metal square tube frames with the sheet metal roof bolted to an original concrete base. I intend to enclose one end (where the tub is at) and a portion of each side for protection for the refrigerator and panel box, to be located on right side (bush obscures that corner). See attached photo.

I had purchased a copper ground rod with strap and #8 bare copper wire to be installed 5'-0" down and 5'-0" vertical (box will be about 5'-0" AFF against enclosure wall). There is not currently, nor do I intend to install, any water line to the structure. Is it your opinion that the combination of a metallic building bolted to concrete and a single ground rod is not enough, and that a second ground rod must be installed at an approximate distance of 8'-0" with another connecting #8 wire ?

In case you aren't told enough, your assistance is greatly appreciated !
7669-ground_rods

Billhart

10:20AM | 09/03/07
Member Since: 04/25/05
1918 lifetime posts
I did not mention metal buidling because I think of "Bulter" buidling. But I think that carport qaulifies.

Here is what the code says. this is for a type of electrode that must be used it available. 250.50(b) "metal Rrame of the Building or Structure. The metal frame of the building or strucure, WHERE EFFECTIVELY GROUND."

That is different from a Ufer (encased contrete electrode). That reads "An electrode encased by at least 2" of concrete, located within and near the bottom of a concrete foundation or footing that is in direct contact with the earth, consisting of at least 20 ft of ...{basically either rebar orr copper wire}.

You don't have that.

But I wonder if the carport is "effectively grounded" by the footings. You really need to as the inspector about that. But you still want ot bond it to the ground electrode system. Or wise it could be electrified if there was a fault.

"I had purchased a copper ground rod with strap and #8 bare copper wire to be installed 5'-0" I had purchased a copper ground rod with strap and #8 bare copper wire to be installed 5'-0""

Ground rod is 8 ft in contact with the soil. Ideal vertically, but can be at an angle if are rocks.

"Is it your opinion that the combination of a metallic building bolted to concrete and a single ground rod is not enough, and that a second ground rod must be installed at an approximate distance of 8'-0" with another connecting #8 wire"

First of all you can't splice the wire it has to be contigous.

And the spacing is at least 6ft not 8.

The lastest (2005) code says that if a ground rod is used then either it has to be tested less than 25 ohms or 2 ground rods installed.

Apparently that was alwasy the intent, but the wording was confusing and where used as a secondary electrode the practice was to only install one.

Now if the metal frame qaulifies as a ground electrode then you don't need a ground rod at all.

But this is an area that a lot of inspectors go more by "local practice" than the exact wording of the code.

natureboy

10:29AM | 09/03/07
Member Since: 09/01/07
4 lifetime posts
I will speak with the inspector again this week before finalizing the grounding system.

If you would like, or care, I would be glad to send photos upon completion, as well as a glowing recommendation to anyone who asks.

Your assistance has been voluminous, and very comprehensive. Bless you ! I hope the purveyors of this site are showing you their appreciation.

Now go and enjoy the rest of today and get off line ;-)
Click_to_reply_button Inspiration_banner

INSPIRATION GALLERY



Post a reply as Anonymous

Photo must be in JPG, GIF or PNG format and less than 5MB.

Reply_choose_button

captcha
type the code from the image

Anonymous

Post_new_button or Login_button
Register

Follow_banner_a
Newsletter_icon Google_plus Facebook Twitter Pinterest Youtube Rss_icon
 
webapp1