Adding Subpanel


Old 05-23-05, 02:23 PM
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Adding Subpanel

Hello i am adding a new subpanel and my question is what size breaker should i use for this.

the reason for the subpanel is that i am adding on 4 new rooms which are follow as

1. 14 x 24 bedroom with a fullsize bathroom

2. new kitchen with build in dishwasher,

3. kids bedroom

4. hallway

5. 14 x 20 bedroom

and also i will be taking some wiring off of the main breaker box and putting them over to the subpanel because that box is full the main breaker box is a 200 amp box.

not sure yet what size of subpanel i should get because i want room for futer addon breakers.

any help would be appreciated.

thank you.
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Old 05-23-05, 03:30 PM
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You need to list the loads you plan on adding more precisely. Will you have:

Electric cooktop/range?
Microwave (built-in/over-the-range)?
Garbage disposal?
Other (trash compactor, convection oven, instant water heater, etc)?

Jazucci / Whirlpool tubs?

Electric heaters, A/C, etc?
Lighting requirements?
Old 05-23-05, 04:08 PM
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sorry about that as for the loads.

the rang will stay on the main where it is now i have enought wire for that to run to the new location.

Garbage disposal, yes forgot about that also not right away but yes to the trash compactor, instant water heater

Microwave yes but not a build in

as for the bedrooms just a computer which is mine and it is a heavy system with all of the networking and more.

small bedroom will have just tracking lighting and tv.

heaters no the furance will handle that.
that is it.
Old 05-23-05, 05:13 PM
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May I ask what size service you have right now.....and are any of the items you are adding in the proposed NEW sub-panel already in use in the existing panel?
Old 05-23-05, 05:27 PM
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my main service pannel is a 200 amp and yes as for what i will be moving from the main to the sub is a 110 hotwater heater which is in the 14 x 24 room and the outlets and lighting from that room. the hot water heater right now is on its own breaker well should say it is wired into the shed becasue all that is in the shed is just a light. the only reason i am moving anything is because i have to make room for the new breaker which takes to slots the main break is only a 18 slot pannel. also as for anything in used i don't have the subpanel yet not sure what to get yet and waiting to see about the breaker size
Old 05-24-05, 07:32 AM
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sorry to bumb this
Old 05-24-05, 07:38 AM
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Are you planning to put the sub-panel in the new addition, or just beside the existing panel box?

Have you checked to see if your existing panel box can use "twin" breakers (aka piggyback, tandem, etc)? See if your panel box label has on it "CTL". If so, you may be able to add circuits to it without adding a sub panel. 18 slots is a tiny main panel.
Old 05-24-05, 07:43 AM
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yes i can add double breakers and the subpannel is going right beside it also this main panel is in a house trailer that i have turn it over to reastate.
Old 05-24-05, 08:23 AM
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Originally Posted by Stealth
yes i can add double breakers and the subpannel is going right beside it also this main panel is in a house trailer that i have turn it over to reastate.

Theres a difference in a twin breaker and a double breaker...a twin takes the space of a SINGLE breaker but is actually TWO breakers. Just want to be sure you are not talking about double-pole breakers, which are the size of two single breakers, look like two single breakers, but have their handles tied together.

If you can replace single breakers with twin breakers, that may allow you to add enough additional circuits in the existing panel with no need for a sub...

I have no idea what you mean by anything you wrote after "house trailer". ???
Old 05-24-05, 08:44 AM
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house trailer what i mean is that is why the main box is only a 18 slot main breaker box.

yes i can take out a breaker and put a double breaker in that way but i am limited on my grounding bars and also the box the way they have it is really messy and i have problems now of breakers tripping on the double breakers that is why i was going with a sub-panel

what i was thinking of is putting a 100 amp breaker for it here is some pictures on what my breaker box looks like now.

image 1

image 2
Old 05-24-05, 09:27 AM
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OK...Can't blame you for wanting to minimize the amount of time your hands are in that. Besides, there's only room for two more twins at the bottom left...unless you want to get into quad breakers to double-up your 220 circuits (I actually have one in my panel box).

Those mains on the left can be intimidating to work around (no way to de-energize them from the panel). Looks like the installer started out neat on the right side, then made a mess on the left. A shame. My panel is not much neater, but at least my mains are out of the way (they come in up top).

A decent sized 100A or so panel would probably be a good solution. Wiring costs will be negligible since you probably only need 5' of length. I'd run a conduit from one panel to the other and use individual conductors. I'd also not fool with Aluminum wire since the cost savings would be so small (it would be a different story if the sub was on the other side of the house).

Try to get the same brand panel you have now (keep it simple) the very least, make sure the 100A (or whatever size you go with) breaker you buy to install in the existing panel is the same brand.

BTW: Have you considered locating the sub-panel close to your new addition? It might be more convenient. Totally up to you though!
Old 05-24-05, 11:09 AM
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the new add on it just on the other side of the breaker box now. if i would just cut though the wall that is the new addon LOL just was going to keep it all facing one way.

also i am not sure what kind of breaker box this is

i do know that i a square D will work in it and there is 2 Bryant breakers in it. also from what i found is that i can only get in square D is a 100 Amp, 6/12 Main Lug Panel

and i want a bigger one like a

GE 12 Space, 125 Amp, Convertible Load Center
Factory installed main lugs
Accepts (12) 1" or (24) 1/2" breakers this one runs 26.87
Murray 125 Amp, 12/24 Load Center
12 spaces, 24 circuits this one runs 32.97

so as you see i am still not sure which one to get or lot else where

Last edited by Stealth; 05-24-05 at 11:27 AM.
Old 05-27-05, 08:37 PM
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just a quick question about the wire to use.

my brother had some wire and i was wondering if you think this wire would work with the 100 amp breaker from the main to the sub.

it is awg 2 al type use-2 60 mils xlp insulation 600 volts. it is for 100 amp breaker he used to run a breaker to his garage. it is alumina.

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