upgrading main breaker

Old 06-10-08, 07:53 PM
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upgrading main breaker

we have a Ge panel from the 1970's I believe, its a 125 amp main breaker. We want to add a electric stove and some other things to the house. I noticed the wire that hooks into the breaker says 1 awg.

with a 1 AWG cable can I simply change the main breaker to 150 or 175, and then just use a sub panel to add more spaces to hook the items we need into.

Basically a cheap way to upgrade?

is this legal need permits? will it work?

Thanks in advance for the help! Great Site!
Old 06-10-08, 08:12 PM
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The only legal way to able determ the service size is load demand just goggle that it will show up few diffrent verison of that.

Once you get the load demand done then it will tell ya if the exsting main breaker box is big engouh to handle the load or not.

150 amp is not super common but there is out on market for 150 amp service but 200 amp is more common and normal to use that.

To order to use 150 amp service you need to use at least 1/0 cu or 2/0 AL conductors.

The 200 amp service use 2/0 CU or 3/0 AL [ normally i use 3/0 CU or 4/0 AL to advoid some gotcha show up in the code]

To order change the breaker box you will have to change the service entrance conductor and pipes if have there. Also the meter socket it will have to upsized to handle 200 amp conductors [ the 200 amp socket is slightly larger than 100 amp sockets ] { ask the POCO for info on the location and height and mast info if go thru the roof }

It can be doable with serious DIY's but normally electrician useally do this in about half to full day.

Any service upgrading will need perments so check with your local inspection office for the latest update info due both state and local code can really varies a bit.

If need more question just ask us here

Old 06-11-08, 12:40 AM
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thanks for reply...

Thanks for the information on full panel replace (I may need it)...

However I am really trying to avoid doing a full panel replace if possible. I guess I was hoping I could leave the 1970's
panel and the service entrance cables and meter I already have in place, and just buy a 150 amp main breaker to replace the 125 breaker that is in there right now.

I have 1 Awg se wire which is copper. That could handle up to 150 amps I beleive. I was hoping I could call the electric company to shut down the power and switch out the 125 main swith for a 150 amp one, leaving the panel and the se cables all just the same as before..

I just kinda wanted to just bump up the amps a little if possible with small expense.

is this cheap upgrade possible legal? Is the 1970's panel able to accept a larger size main breaker?

or do I just need to bite the bullet for the 200 amp service upgrade as previous post outlined?

p.s. if the plan is possible then the
other half of the plan is to buy a new subpanel to replace the houses original 1960's 50 amp panel. the 50 amper is now being used as a subpanel to the 125 amp (1970) panel. I would add a much larger subpanel with modern breakers and extra spaces using 75 or 100 amp feed.

would this work?

Any help appreciated! (sorry so long)
Old 06-11-08, 05:37 AM
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The #1 copper is good for up to 150A in this case; however there must be a reason the original electrician installed a 125A breaker. I suspect that the bus bars in the panel itself may be 125A max. Also possible that the meter can is 125A max. May they don't make a 150A breaker that's listed for that panel. You would have to investigate each of those things before you could proceed.

Why is the upgrade necessary? Is your demand load calc close enough that you are just a few amps over 125A?
Old 06-11-08, 05:48 AM
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You may not even need to do a panel upgrade to install an electrci stove. You need a load calc first.
Old 06-11-08, 08:26 AM
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thanks very much for the info..

I didn't realize the panel buss bar and the meter especially would be rated for a certain amount of amps.. duh on me kinda..

Great site Good to know now! thanks for the posts! I will check into this stuff slightly but I think the 150 bump up idea is dead.

. I will run a load calc. however along with regular house stuff we have a 5 ton ac unit, a swimmping pool, 3-4 computers, and were adding 4 120 sq ft small sheds with 5 amp ac units and lights etc in each one.

the tricky part of the load calc has to do with whats running at one time. lol in this house hard to know.

I sort of figured before the oven even adding the sheds we were ok but kinda close,

so hehe maybe gas stove (thats the debate) or upgrade panel.

Anyhow thanks for the help! Great site!

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