Need review of my plans - sub panel at shed

Reply

  #1  
Old 06-23-13, 11:03 PM
Member
Thread Starter
Join Date: Sep 2008
Posts: 17
Received 0 Votes on 0 Posts
Need review of my plans - sub panel at shed

I want to put a sub panel on my shed that will run a 1hp 10amp double insulated pool pump (std 3 prong plug), and a convenience outlet (for above ground pool).

My plan:

Already dug a 20inch trench (my god that was a nightmare)

Put in a 60amp 2 slot 4 circuit box
Put in a 20amp for the pump
Put in a 20 amp for convenience (I could go bigger on both but its overkill already)

Run four 6 awg wires in a 1 inch electrical PVC conduit (individual with sheathed wires). The run is approx. 100ft

Put in a 60amp double breaker at the main panel

--------

Does that cover the basics of adding a sub panel? I am concerned about the gauge and if there is any code specifying conduit size (1 inch seems plenty).

Additionaly, I am going to try to bring it up right under the main panel. My house is newer and all electrical is run from ceiling which should make the bottom clear. If I have to run it horizontally, what interior conduit is to spec? Does the liquidtite non-metallic flexible conduit meet code?

Thank you very much. I tried to do my homework before bugging you guys.
 
Sponsored Links
  #2  
Old 06-23-13, 11:32 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 54,520
Received 506 Votes on 476 Posts
Looks good.

You can run a #8 for ground instead of #6.
Be sure to run THWN wiring as it's in the presence of water.
1" conduit is good.

I would put in a ground rod at the sub panel location connected to panel with #8 wire.

Remember at the sub panel you will need to keep the neutrals and grounds separate. The panel should come with an insulated neutral bar. You may have to purchase a grounding bar.

It's looking like your loads will be 120 volts. You will need GFI breakers or receptacles.
 
  #3  
Old 06-24-13, 07:01 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,996
Received 39 Votes on 34 Posts
A 60 amp feeder is way more than you need. YOu could save some money and install a 30 or 40 amp feeder.

You cannot install overcurrent protection greater than 20 amps for standard receptacles.

Any receptacles outside will need to be marker WR for weather-resistant in addition to the in-use covers and GFI protection. You will also need to keep the receptacles the proper distance away from the pool.

The ground for the pool circuit needs to be insulated.
 
  #4  
Old 06-25-13, 09:11 AM
Member
Thread Starter
Join Date: Sep 2008
Posts: 17
Received 0 Votes on 0 Posts
Thank you for your help. I purchased everything yesterday, and it was painful (more than I expected).

My shopping generated a couple new questions.

I purchase a panel, timer, and receptacle. What conduit can I run between the 3 boxes?

I also need to put in a ground rod. I was told that the code requires 8 feet. There is no way on this earth I will be able to get 8 feet of rod vertically into the ground. Are there other options (burry it horizontally)?
 
  #5  
Old 06-25-13, 09:47 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,996
Received 39 Votes on 34 Posts
PVC conduit is easy to work with. Depending if physical damage is an issue you might not even need conduit.

(G) Rod and Pipe Electrodes. The electrode shall be installed
such that at least 2.44 m (8 ft) of length is in contact
with the soil. It shall be driven to a depth of not less than
2.44 m (8 ft) except that, where rock bottom is encountered,
the electrode shall be driven at an oblique angle not
to exceed 45 degrees from the vertical or, where rock bottom
is encountered at an angle up to 45 degrees, the electrode shall
be permitted to be buried in a trench that is at least 750 mm
(30 in.) deep. The upper end of the electrode shall be flush
with or below ground level unless the aboveground end and
the grounding electrode conductor attachment are protected
against physical damage as specified in 250.10.
 
  #6  
Old 06-25-13, 11:13 AM
Member
Thread Starter
Join Date: Sep 2008
Posts: 17
Received 0 Votes on 0 Posts
I wasn't sure if I could use PVC. I know the panel has to be grounded and I wasn't sure if all the other enclosures have to be grounded as well using metal conduit of some sort between them.

I guess I will see how far the bar goes down using an impact hammer.

If it doesn't go down far, I can dig a 30 inch trench and cut the rod up into equal segments and burry them in the trench vertically and use a continuous ground wire #8 to connect the rods to the panel?

I have some really hard soil. Digging the 20 inch trench for the wire as a nightmare.

I appreciate all your help. Its hard to research this stuff. Is there a website that allows you to search the NEC code by keyword?

I am not going to get into bonding yet. My pump is double insulated and the pool has vinyl top rails and verticals. I am not sure what I could bond it to. I think the pool manufacturers are building pools that make parts of the code unnecessary.

I think its a solution looking for a problem. I would wager you couldn't find a single injury due to a difference in ground potential. GFI(s) prevent the majority of electrical related pool deaths (60 or so in 13 years, many of those were from shock outside the pool or didn't have GFI).
 
  #7  
Old 06-25-13, 11:31 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
I wasn't sure if all the other enclosures have to be grounded as well using metal conduit of some sort between them.
The circuit must contain a ground wire (EGC) if PVC is used but if you use plastic boses they of course don't need grounding. The EGC though must be connected to all devices and fixtures that have a ground connection.

EMT can not be used for direct burial. Cable can not be used for pools.
 
  #8  
Old 06-25-13, 08:02 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,996
Received 39 Votes on 34 Posts
The rod cannot be cut up.

The water on the pool will get bonded. There are bond fitting made to do this.

Does the pool have metal sidewalls?
 
  #9  
Old 06-25-13, 09:23 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
Received 1 Vote on 1 Post
I guess I will see how far the bar goes down using an impact hammer.
I only do that if I have a ground rod socket that fits into the hammer. Besides driving the rod far enough out from the structure to miss any footings, there's a trick that others and I have used to drive a ground rod through a paved parking lot and other challenging materials: Pick the spot and lay a 3/8" washer on the ground. Set the tip of the ground rod in the center of the washer and start driving. My go-to tool for driving the rod is my 16 oz. claw hammer.
 
  #10  
Old 06-26-13, 07:44 AM
Member
Thread Starter
Join Date: Sep 2008
Posts: 17
Received 0 Votes on 0 Posts
Pick the spot and lay a 3/8" washer on the ground. Set the tip of the ground rod in the center of the washer and start driving. My go-to tool for driving the rod is my 16 oz. claw hammer.
How does that work?

The water on the pool will get bonded. There are bond fitting made to do this.
The pool has metals sides, none of which you can touch while in the pool, its all encapsulated in vinyl.

I am still considering whether or not I will bond the metal on the pool and water. I see it as a solution to a problem that doesn't exist in an above ground pool. What does it solve? There is no electricity coming into contact with the metal or water, the pump is double insulated. As for "ground potential differences", it would be rare indeed that there is enough difference in ground potential to cause injury.

I have yet to find anything that justifies those measures in an above ground pool, especially in a real world scenario.

As I said, 60 electrical deaths in 13 years, most if not all is due to lack of GFI or fault GFI and people using appliances in or around their pool (radios and such). Why add more to an electrical code that was already effective?

The more I deal with codes, the more of a libertarian I become.
 

Last edited by Nashkat1; 06-26-13 at 11:59 AM. Reason: Format quotes
  #11  
Old 06-26-13, 12:04 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
Received 1 Vote on 1 Post
Originally Posted by Nashkat1
Pick the spot and lay a 3/8" washer on the ground. Set the tip of the ground rod in the center of the washer and start driving. My go-to tool for driving the rod is my 16 oz. claw hammer.
How does that work?
Two answers:

1> One hammer tap at a time.

2> IDK, but it does. At least, it has IMX.

The more I deal with codes, the more of a libertarian I become.
All of the electrical advice we give here is, and will be, based on the current cycle of the NEC, while recognizing that local codes may, and do, vary from that. That said, if you don't want to take the advice offered here then we can't help you.
 
  #12  
Old 06-26-13, 12:45 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
You can use a hammer drill to install a ground rod. They make holders for that purpose but you can just chuck it in the drill. Example Ground Rod Driver | Milwaukee Tool
 
  #13  
Old 07-01-13, 07:10 PM
Member
Thread Starter
Join Date: Sep 2008
Posts: 17
Received 0 Votes on 0 Posts
Thank you Ray. I will get one when that time comes. In digging my trench I ran across the grounding rod (two, in separate places) for my service and another for, well I haven't figured that out, I think the AC unit.

They were steel. I am wondering if I need to go with steel vs copper due to how hard the earth is. Well see.

Nashkat1, I appreciate the advice. The vast majority of codes make sense, some due not. In this discussion I specifically question why I need to bond an AGP that has no exposed metal.
 
  #14  
Old 07-01-13, 07:52 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
Ground rods are copper coated steel.
 
  #15  
Old 07-01-13, 10:25 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
Received 1 Vote on 1 Post
In this discussion I specifically question why I need to bond an AGP that has no exposed metal.
How else would you reduce the potential in the pool to zero? Are you an electrical engineer?

The vast majority of codes make sense, some due not.
If you will post references to those sections that puzzle you, we may be able to provide some insight into their utility and/or necessity.

In digging my trench I ran across the grounding rod (two, in separate places) for my service and another for, well I haven't figured that out.
A third ground rod, or are you asking about only two connected in series?
 
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: