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Wiring New 100 amp Subpanel for Kitchen, from 200 amp Service Panel

Wiring New 100 amp Subpanel for Kitchen, from 200 amp Service Panel

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  #1  
Old 10-04-13, 03:43 PM
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Wiring New 100 amp Subpanel for Kitchen, from 200 amp Service Panel

I want a subpanel not far from my kitchen, for all the kitchen circuits. There are only just enough slots on my GE Powermark 200 amp service panel if I don't use a sub panel, because my house has thirty eight circuits. The Ge service panel only has 40 slots. (if I had know this I would have got a service panel with 66 slots! Too late now. The kitchen has 13 circuits and then there another close to the kitchen for the outside GFCIs and the back porch light. So I want a subpanel that can accommodate at least 16 circuits. So...what I want to do is add a 100 subpanel, and have it nearer the kitchen/back door. (Can I use something like this at the main service panel for the subpanel: General Electric THQL21100 Thick Series 2-Pole 100-AMP Circuit Breaker? If not, can you suggest the right type of GE breaker?).
Here are the circuits at a minimum
Kitchen Counter sabc1 GFIC -20A
Kitchen Counter sabc2 GFIC -20A
Kitchen Counter sabc3 GFIC -20A
Kitchen Counter sabc4 GFIC -20A
Kitchen Counter sabc5 GFIC -20A
Kitchen Counter sabc6 GFIC -20A
Disp-DW -20A
Microwave -20A
Range Hood -15A
Gas Stove -15A
Fridge -15A
2 wall outlets NOT on countertop sabc -15A
Back Porch Light/ Basement Stairwell Light/outside GFCIs -20A
As you can see I like the counter top GFCIs to be separate from one another.
The run from the kitchen subpanel to the service panel is about 60 feet. What size wire do I need?
Can you suggest a very good quality subpanel that has 16 (hopefully more than 16) slots? I stay away from Square D and will not use anything they make.
 
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  #2  
Old 10-04-13, 06:43 PM
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The run from the kitchen subpanel to the service panel is about 60 feet. What size wire do I need?
#2 aluminum SER cable is pretty commonly used for a subpanel such as you are planning to install.

Can you suggest a very good quality subpanel that has 16 (hopefully more than 16) slots? I stay away from Square D and will not use anything they make.
I'd use either a Cutler-Hammer CH series panel with standard copper bus or possibly a Siemens panel with optional copper bus. The Cutler-Hammer breakers carry a lifetime warranty, not sure on Siemens warranty, but it's at least 10 years. Regardless, I would use a copper bus panel.

As you can see I like the counter top GFCIs to be separate from one another.
It's not necessary to have each countertop small appliance receptacle on a dedicated circuit. In my opinion, it's a waste of materials and labor.
 
  #3  
Old 10-04-13, 09:56 PM
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I want a subpanel not far from my kitchen, ... The kitchen has 13 circuits and then there another close to the kitchen for the outside GFCIs and the back porch light. So I want a subpanel that can accommodate at least 16 circuits.
You listed 13 circuits total, but I don't see a lighting circuit for the kitchen there.

Here are the circuits at a minimum
Kitchen Counter sabc1 GFIC -20A
Kitchen Counter sabc2 GFIC -20A
Kitchen Counter sabc3 GFIC -20A
Kitchen Counter sabc4 GFIC -20A
Kitchen Counter sabc5 GFIC -20A
Kitchen Counter sabc6 GFIC -20A
Disp-DW -20A
Microwave -20A
Range Hood -15A
Gas Stove -15A
Fridge -15A
2 wall outlets NOT on countertop sabc -15A
Back Porch Light/ Basement Stairwell Light/outside GFCIs -20A
You can run as many circuits as you like, but this is closer to the minimum number needed with the lights added:
Kitchen Counter SABC1 GFCI -20A
Kitchen Counter SABC2 GFCI -20A
Disp-DW -20A
Microwave -20AkI
Kitchen Lights - 15A
Range Hood -15A
Fridge -15A
2 wall outlets NOT on countertop SABC -15A
Back Porch Light/ Basement Stairwell Light/outside GFCIs -20A
9 circuits. The controls for your gas range can be fed from one of the SAB circuits - usually tied in ahead of the GFCI protection.
 
  #4  
Old 10-04-13, 10:02 PM
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Thanks for the replies.
I found: Eaton 24-Circuit 12-Space 125-Amp Main Lug Load Center
Even thogh it says 125 amp can't I use a 100 amp breaker for it at the main service panel and use it as though it were a 100 amp subpanel. I can't find a 24 circuit 12 space, 100 amp. Also can't one use a main breaker panel as a sub panel (I DID find many main breaker panels @100 amp having 20 or more spaces)? If so what must one do to use it so?
 
  #5  
Old 10-04-13, 10:17 PM
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The reason you don't see kitchen lighting listed is that the kitchen lighting is already a up-and running dedicated separate circuit coming from main panel: Kitchen-Dining room lighting, 15A --- there are NO outlets or anything else on this lighting circuit.
I'd rather not have just two SABC for the six GFCIs what if someone runs a 1200W appliance and a toaster oven on one of the only two SABCs? It might trip the breaker - no real harm done. But I'd like at least 4 counter top SABC GFCIs minimum.
Thanks for pointing out that gas stove can run off of one SABC, I forgot about that.
 
  #6  
Old 10-04-13, 10:30 PM
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can't one use a main breaker panel as a sub panel (I DID find many main breaker panels @100 amp having 20 or more spaces)?
Sure. The packages where you get a panel plus a main breaker and maybe 5 or 6 branch circuit breakers are often the best value.

If so what must one do to use it so?
Just install it. The breaker that you install in your main panel to protect the feeders for the subpanel are its overcurrent protection. The main breaker in the subpanel will be a service disconnect.

Some other stray points that come to mind:
  1. Looking back over your list of loads, this looks more like a 60A than a 100A sub;
  2. The non-GFCI circuits need to have AFCI protection in the panel; and
  3. The neutrals need to be isolated and the grounds need to be bonded in your subpanel. You'll probably have to buy an add-in ground bar to do that.
 
  #7  
Old 10-05-13, 12:07 AM
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I'm not happy with aluminum wire - perhaps it's because it acquired a bad reputation in the 70s or thereabouts. Might be perfectly fine, I guess. Dunno. Can anyone give me a price comparison between #2 Aluminum and the requisite copper size for this application? They used real heavy aluminum for my service entrance wire for my 200A load center - I think 4/0 . Not sure about the size nomenclature; anyway it was supposedly quite a fair bit larger than what you normally get for a 200A load center. Went up to the panel real close to inspect to make sure they put on anti-corrosion "grease". They did. But not nearly the amount of grease that I would have put on it. Having be an electronics tech* for many years, back when I was young, I frown upon aluminum It has it's place but I'm not fond of it. But if the price for copper is outrageous then I'll use aluminum.

*You have to take into account that as a electronics tech (communications, avionics) I was accustomed to 22 - 28 AWG wire! I would have thought of #2 as being as large as an elephant at that time!
 
  #8  
Old 10-05-13, 12:13 AM
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thanks Nashkat1,
How do you arrive at 60 amp, given all those 20 amp circuits I listed. Is it because it's unlikely anyone could run a lot of stuff on the SABCs all at one time and the fact that there a gas stove vs. an electric?
Then if I do use a 60A sub panel what wire size do I need?
Upon reflection the run from the main service panel to the sub panel would be closer to 50 ft than 60 ft that I said earlier.
The other thing is it looks to me that of the 60A main lug panels I perused, they don't give you very many slots, in many cases a chinsy eight or so. That's all.
 

Last edited by applejak_2000; 10-05-13 at 12:33 AM.
  #9  
Old 10-05-13, 07:39 AM
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I found: Eaton 24-Circuit 12-Space 125-Amp Main Lug Load Center
Do you have a catalog number for the Eaton panel, it could be either a CH series or BR series. The CH series has standard copper bus; panel and breakers have a lifetime warranty. The BR series could be either aluminum or copper bus; panel and BR breakers have a 10 year warranty. There is a substantial difference.

I'm not happy with aluminum wire - perhaps it's because it acquired a bad reputation in the 70s or thereabouts. Might be perfectly fine, I guess. Dunno. Can anyone give me a price comparison between #2 Aluminum and the requisite copper size for this application?
I cannot give you a price comparison between aluminum and copper, but I can tell you copper is much more expensive. Copper SER cable would be extremely hard to find, but could always be ordered. The alternative could be to install 3 - #3 copper THHN conductors and 1 - #8 Grn THHN conductor in 1 1/4" conduit.

If I were to use the #2 aluminum SER cable, I'd prefer to protect it with a 90 amp breaker. I am not an aluminum fan either, but it has it's place in services and branch feeders when properly installed and terminated.
 
  #10  
Old 10-05-13, 09:12 AM
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I found an Eaton
model CH24L125CP
125A 12 space, 24 circuit. But again can one use a 125 amp subpanel as a 100 amp? The other alternative is to use a main panel as a subpanel, at least you get a fair amount of spaces. The smaller subpanels give you measly 6 spaces or something of the like.
 
  #11  
Old 10-05-13, 10:24 AM
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I found an Eaton
model CH24L125CP
125A 12 space, 24 circuit. But again can one use a 125 amp subpanel as a 100 amp? The other alternative is to use a main panel as a subpanel,
Good choice, although I prefer not to use tandem breakers. Yes, you can feed that panel with any size breaker you'd like as long as it doesn't exceed 125 amps.
 
  #12  
Old 10-05-13, 11:59 AM
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How do you arrive at 60 amp, given all those 20 amp circuits I listed. Is it because it's unlikely anyone could run a lot of stuff on the SABCs all at one time and the fact that there a gas stove vs. an electric?
Yes. Panel and feeder sizes are determined by calculating the total load. The circuits in your main panel probably add up to more than 200 now and you haven't installed the breaker for the subpanel yet.

To get the answer to that question you can do a residential load calculation for the subpanel. There are a number of calculators available online. I've found the Excel template from Mike Holt Enterprises to be useful and accurate. It's the 5th link from the bottom on this page.

Then if I do use a 60A sub panel what wire size do I need?
6 AWG copper for the two hots and the neutral. The grounding conductor can probably be smaller but I can't find the reference quickly right now.

But again can one use a 125 amp subpanel as a 100 amp?
A panel can be used for any level of power up to it's maximum rating. That panel can be used for either a 100A or a 60A feed.

The reason you don't see kitchen lighting listed is that the kitchen lighting is already a up-and running dedicated separate circuit coming from main panel: Kitchen-Dining room lighting, 15A --- there are NO outlets or anything else on this lighting circuit.
OK. That gets you down to 8 circuits minimum.

I'd rather not have just two SABC for the six GFCIs what if someone runs a 1200W appliance and a toaster oven on one of the only two SABCs? It might trip the breaker - no real harm done. But I'd like at least 4 counter top SABC GFCIs minimum.
That's fine. Two 20A GFCI-protected SABCs is the minimum required by code, so I used that number to calculate the minimum total number of circuits you need. You can install as many as you like.

*You have to take into account that as a electronics tech (communications, avionics) I was accustomed to 22 - 28 AWG wire! I would have thought of #2 as being as large as an elephant at that time!
Since most of my work was on commercial and industrial jobs, I'm accustomed to pulling parallel 4/0 feeders into switch gears you have to climb into to make up the connections. 14 AWG looks like fettuccine to me! The year or two we spent upgrading the fire and intrusion systems for a transit system was a radically different experience.
 
  #13  
Old 10-06-13, 03:23 PM
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Then if I do use a 60A sub panel what wire size do I need?
6 AWG copper for the two hots and the neutral. The grounding conductor can probably be smaller but I can't find the reference quickly right now.
The grounding conductor would be a #10.
 
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