bigger box or sub box?

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  #1  
Old 09-11-12, 11:35 PM
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bigger box or sub box?

Ok I need some advice. I have completed inspections for electrical.
I have on my own with your guys help added
Bath
Kitchenette
bedroom
movie room
living room
I found out that a kitchen does not need arc protection in CO however a kitchenette does. ;(
So before final inspection I need to have arc breakers for the kitchenette. Sure you say cool just add them well thatís the problem. I am out of room. I need to add a sub box or a larger main box.

Any recommendations? I spend a few min with the inspector nice guy by the way. He told me if I put in a bigger box I would have to run a bigger ground to the water line coming in and add a #4 to the water jumper whatever that is. How hard would it be and would I have as much code to worry about if I placed a sub box to the side of the main box? What are my limitations and what electrical codes do I need to be aware of? Do I still need to run a new bigger copper line to the water main and so on? Whatís the limitations on the amps a sub can be ect?

Thanks for all the great help guys.

Rob
 
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  #2  
Old 09-12-12, 05:14 AM
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Rob, if the kitchenette is already wired why can't you change to an AFCI breaker?

The term larger panel needs to be clarified. A higher amperage panel will require a larger conductor to the water lines. A panel with just more breaker spaces, but thge same ampacity would not. A subpanel would not.

The subpanel should be sized for the loads to be expected on it.
 
  #3  
Old 09-12-12, 01:04 PM
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He was saying a larger panel. Not larger amps from my understanding. I have 150amps coming in or at least the main breakers say 150 on all 4. He was just saying a bigger main panel or put in a sub panel. It sounds like a sub is easier to me. I would put in a 125 amp sub I think if I went that direction. My problem is room arc breakers are so big and I will have 10 of them at 15/20 amps. So itís more of a room issue not amp issue from my understanding.
 
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Old 09-12-12, 01:42 PM
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The AFCI breakers are just longer. They do not take up any more space vertically.
 
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Old 09-12-12, 04:31 PM
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GE the arc breaks are full size not mini. I have no room left and its a mini breaker i am using now but i need to put a full size now.
 
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Old 09-12-12, 05:21 PM
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Oooo, That is one of the reasons I do not care for GE panels.

Adding a subpanel will be MUCH cheaper then changing out a whole panel. 150 amps should be plenty. Just move some smaller loads to the sub panel.
 
  #7  
Old 09-12-12, 07:55 PM
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I got a 125 amp sub. I think at this point the only question i have is according to 2011 nec how do i ground the sub? Do i just run a ground from the main which will be like 3 feet away for me or do i have to run a brand new ground to the main water pipe in the basement?
 
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Old 09-12-12, 08:20 PM
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I think at this point the only question i have is according to 2011 nec how do i ground the sub? Do i just run a ground from the main which will be like 3 feet away for me or do i have to run a brand new ground to the main water pipe in the basement?
You only need to extend the GEC from your main panel to your subpanel, since they're both in the same structure. In the subpanel, the neutrals need to be electrically isolated from everything including the can. The grounds need to be bonded to the enclosure. Most panels come with only one multi-terminal bus. If that's the case with yours, and if that bus can be mounted to be isolated, then you need to buy and install a separate bus for the grounds.
 
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Old 09-12-12, 08:22 PM
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You ground from the main only so long as it is in the same building. You need a bonded ground bar and an isolated neutral.
 
  #10  
Old 09-12-12, 09:23 PM
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i bought a sub that has the neutral isolated and ground bonded already. What size ground for a 125 amp sub do i need to run from the main to the sub?
 
  #11  
Old 09-13-12, 05:20 AM
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What size breaker are you using to feed the subpanel?

If the green screw or bond strap is already installed it should be removed. The ground bar only connects to the enclosure.
 
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Old 09-13-12, 07:13 AM
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i bought a sub that has the neutral isolated and ground bonded already.
Then you should be good to go on that.

What size ground for a 125 amp sub do i need to run from the main to the sub?
That depends on
Originally Posted by pcboss
What size breaker are you using to feed the subpanel?
 
  #13  
Old 09-13-12, 05:14 PM
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What size ground for a 125 amp sub do i need to run from the main to the sub?
I would install a 2 pole 100 amp GE Type THQL breaker in the main panel to feed the sub. Then I'd use 3 - #3 copper conductors for my 2 hots and 1 neutral and 1 - #8 green conductor for the ground. I'd connect the two panels with 1 1/4" EMT conduit and install a plastic insulating bushing on the threads of each connector. Follow the instructions already given to be sure the neutral bar isn't bonded to the panel box and land all the ground wires in the separate bonded ground bar. The 125 amp sub you bought is a rating of the interior and doesn't need to be fed with a full 125 amps, 100 is just fine for your purposes.
 

Last edited by pcboss; 09-13-12 at 06:00 PM. Reason: added conductor material
  #14  
Old 09-14-12, 03:01 PM
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Cool thanks i will do that!!
 
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Old 09-17-12, 04:00 AM
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I feel i have an understanding of everything but what this is "install a plastic insulating bushing on the threads of each connector" what is this? what does it look like?
 
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Old 09-17-12, 05:03 AM
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