Electricians of Lemmy: Planning a kitchen re-wire. Sub-panel or direct run?

Submitted ⁨⁨2⁩ ⁨days⁩ ago⁩ by ⁨admiralpatrick@lemmy.world⁩ to ⁨[deleted]⁩

My kitchen is from the 50s and has been updated somewhat over the years by previous owners. The wiring has all be updated to Romex but it’s still all running from two circuits, and one of them is inconveniently placed and practically useless. The end result is I can only use one countertop appliance at a time without tripping a breaker. Only the dishwasher and oven have dedicated circuits.

I’ve lived with this limitation long enough. My 2026 project is to put each outlet on its own circuit and move a couple other outlets from circuits that are shared with adjacent rooms. In all, it’s looking like it’s going to be 5 or 6 total circuits.

Would I be ahead to do a single big circuit from the breaker box and break it out in a sub-panel for the kitchen or just run new individual circuits up from the main breaker box?

Secondary question:

Assuming I do the sub panel and break out five 15 amp circuits in the kitchen, that’s 75 amps. I only have 100A service from the meter. I do not ever anticipate drawing 75 amps from the kitchen outlets at once, but AFAIK codes require that I account for the possibility.

Would it meet code (NEC) to put a 30 amp “main” breaker on the sub-panel that feeds 75 amps worth of 15 amp circuits (or, alternatively, feed the sub-panel from a 30 amp breaker in the main panel)?

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Proprietary_Blend@lemmy.world ⁨2⁩ ⁨days⁩ ago
Hire a licensed electrician.

NEC requires two 20 Amp, 1-Pole devices for small appliance branch circuits. Put the refrigerator on a dedicated 15 Amp, 1-Pole. This will be about 33 Amps.

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Zwuzelmaus@feddit.org ⁨2⁩ ⁨days⁩ ago
In a kitchen you want 3 phases, and at least 5 breakers:

3 phases with a breaker on each for the stove
1 breaker for appliances and other wall sockets
1 breaker for ceiling light and maybe other lights

So when a breaker for the stove blows, then the rest of your kitchen is unaffected, etc.

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- admiralpatrick@lemmy.world ⁨2⁩ ⁨days⁩ ago
  Stove’s already on a dedicated breaker.
  
  This is the US and we only have split-phase (two ‘hot’ legs at 120v on each end of a center-tap transformer)
  
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- Badabinski@kbin.earth ⁨2⁩ ⁨days⁩ ago
  OP is in the US, so no 3 phase power unfortunately ):
  
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Blue_Morpho@lemmy.world ⁨2⁩ ⁨days⁩ ago
It’s a gigantic hassle to pull more wires but if time/money doesn’t matter, I prefer centralized panels.

Think about someone else walking into your house and needing to fix a problem. They wouldn’t know to check the kitchen has its own sub panel.

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- admiralpatrick@lemmy.world ⁨2⁩ ⁨days⁩ ago
  Unfortunately, time and money are factors. Not that I want to cheap out, I just thought maybe a sub panel might be more economical.
  
  They wouldn’t know to check the kitchen has its own sub panel.
  
  I mean, when there’s only a 40 amp breaker labeled “Kitchen S/P” I think they’d figure it out.
  
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Brkdncr@lemmy.world ⁨2⁩ ⁨days⁩ ago
Upgrade to 200A panel if you’re already going through the hassle of significant wiring. You’ll be able to run more circuits to that room.

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- admiralpatrick@lemmy.world ⁨2⁩ ⁨days⁩ ago
  I have room in the panel now, that’s not the problem. Was just thinking it would be more economical to run one big circuit from the basement up to the kitchen and do the breakout there versus running 4-6 new individual circuits all that way.
  
  Upgrading to a 200A panel is on the horizon though not right at this moment.
  
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bluGill@fedia.io ⁨2⁩ ⁨days⁩ ago
Consistency. If you are going to run a subpanel to each room I'd like sub panels, but a mix is not what you want as then nobody is ever sure where to find things. The worst would be a subpanel but some circuits run back to the main anyway - lights is the likely area to see this as those are often shared between several rooms.

If you add a subpanel make sure you can get at it easially to add more in the future. You never know what else you might want in the future. That you think a 30 amp break in the main panel is enough implies that you have a gas stove/oven - you might want to switch to electric in then future for various reasons. Thus make sure there is space for 6 more circuits (2 for the cooktop, 2 for the oven, and 2 for things nobody has thought of today) For the same reason you should get at least 75 amps to that subpanel - even though you will likely only use 30 at max you want that extra space for the future. (I'd go 100 - it doesn't cost that much more and you can upgrade the main panel in the future.

I don't recall NEC saying anything about how much a subpanel needs to feed with, other than "enough". I haven't checked the latest though. Still 30 amps doesn't seem enough for a kitchen even if allowed - some day you will throw a party and that won't be enough for all the things pluged in. NEC requires 2 different 20 amp circuits for counter top use, 15 amps is not allowed, and if I were you I'd consider putting in 3 just to be sure. I'd say less than 50 amps isn't enough for your current uses (and I'd go for 100 on the assumption that the main service gets upgraded some year)

Honestly though, most people don't use subpanels for a kitchen. It doesn't save money and most decorating plans cannot work around a subpanel - this ends up being the big killer.

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- admiralpatrick@lemmy.world ⁨2⁩ ⁨days⁩ ago
  The kitchen would be the only room with a subpanel.
  
  As stated in the post, the oven is already on a dedicated 30A circuit, and I’m not going to mess with that. There’s an empty void near the oven, though, and my thought was to run another 30 amp circuit up beside that to feed the subpanel and place it in that “void”. Decorating isn’t a concern for the void as there’s not much that can really go there anyway.
  
  Definitely want to future proof it, yeah. I’m not married to 30 amp delivery to it, just used that as a reference point.
  
  NEC requires 2 different 20 amp circuits for counter top use, 15 amps is not allowed,
  
  That I didn’t know (or rather, haven’t read yet). Current ones are on 15 amp circuits, so I was going by that (not that previous owners seemed too concerned with “code” LOL).
  
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  - bluGill@fedia.io ⁨2⁩ ⁨days⁩ ago
    Panels need to be accesable I'm not sure what you mean by void, but it may not be an allowed location.
    
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Reverendender@sh.itjust.works ⁨2⁩ ⁨days⁩ ago
Oddly, I am in the opposite situation (My house was built in 1943). New 200V breaker box, old wiring (2 different ages!). How much did your wiring cost you, and did you do it yourself?

My understanding is that either solution you are considering is good. The electrician I used even told me I could put my old breaker box on the other side of the house to do what you suggested, but the only real advantage is shortening some of the wiring runs. Would love some other opinions on this.

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