DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Electrical (
-   -   200 Amp service really needed for a 830 sq ft house? overkill? (

alexz 07-24-2007 06:11 PM

200 Amp service really needed for a 830 sq ft house? overkill?
My little house currently has a 100 amp fuse box, which does not have the capacity to add more circuits. I'm completely renovating the kitchen and adding a microwave over the range, a DW, a food disposer and a second small appliance line to the counter. I may add two ceiling fans at one point. My house is currently running central A/C, central gas furnace, a clothes washer, an electric clothes dryer and an electric water heater.

One 'electrician' (working on obtaining his license) told me that I can install a 125 amp circuit breaker box on the existing service wiring (drop, meter etc), which would prevent some additional work. Another electrician told me over the phone that I should upgrade to 200 amps and they'd have to redo the service drop, meter etc. I'm also looking to move the panel from the outside to inside the basement/garage so I don't have to deal with pulling cable through conduit when I add a new circuit. $1800 was the over-the-phone quote the first electrician gave me. I'm no longering considering using the unlicensed 'electrician', as he's failed to return my phone calls and follow up on like he said (in addition to be unlicensed). I have a licensed electrician who's a friend of a friend coming to look at my situation tomorrow. So how should I react if he tries to sell me 200 amp service? And can I really install a 125 amp circuit box, provided of course, that I can find one that can accomodate my estimated need for 23 circuits. Is adding the said kitchen appliances and ceiling fans really going to add more than 25 amps to my current electrical load that I'm drawing?

I know a single circuit isn't an indicator of your overall electrical demand, but there's only been one blown fuse in 18 mo's I've lived in this house - and that was when my mom was using her hairdrier that was plugged into the lighting circuit (yes, my only recept. in the bathoom comes from the vanity with built in lighting that's connnected to the lighting circuit and yes, I'll rewire the bathroom more accordingly one day). I am single and god help anyone who must share a house this size with more than one person (I guess New Yorkers do it all the time though). Even with another person living in this house, would an

Then there's a very slight chance that I'll add another BR and bath to this house if real estate in this town gets out of control and buying a larger house would be more expensive than doing an addition. Otherwise, I'll be selling in about 5 years (if I continue to get my standard pay raises). So I do want to look at resale value. But the cost of going to 200 amps may be twice as much as doing this 125 amp box .... and I have a lot more work to do on this house ($$$).

Thanks for taking the time to reply!


HouseHelper 07-24-2007 07:26 PM

Square D makes a 30 space 100A panel (QO) that could work. There is also no reason you can't add a 40 space 200A subpanel and feed it though a 100A breaker. Just to get circuit space is not reason enough to spend thousands for an upgrade if you really don't need it.

alexz 07-24-2007 07:46 PM

Thanks for replying .... I like your idea of .... (and two other questions)
..... adding a 200A subpanel to get the circuit breaker 'spaces' that I need. So does this mean that my 100 amp fuse box that's outside of my house would remain? And then wires would run from it to the 200 amp subpanel (ideally on the inside)? Or should the 100A fuse box be totally removed? So it sounds like you can have have a 200A box on 100A service, but you could never use a 100A panel on 200A service.

My first other question --> Can the existing service wiring feed a 125A panel? Getting an extra 25A would be nice, especially if it won't cost me much more.

My second question --> So it does sound to you that 200A is overkill for a house this size that will probably never house more than 2 people at a time. Would 100A suffice for what I want to do? 125A (if possible)?


HouseHelper 07-24-2007 09:22 PM

Without seeing your particular setup, I can't say whether your existing service wiring can handle a 125A panel. But as I said before, you can always add a subpanel to your existing service that is rated higher, but is still protected by the 100A main breaker. If you do decide to redo the entire service, go with 200A. The difference in cost is negligible and then you will be set when you add the bedroom, bath, pool, and hottub.:thumbsup:

SecretSquirrel 07-25-2007 07:07 AM


Originally Posted by alexz (Post 54410)
My second question --> So it does sound to you that 200A is overkill for a house this size that will probably never house more than 2 people at a time. Would 100A suffice for what I want to do? 125A (if possible)?

My Electrician days were back in the early 80's. Even then, a 200 amp main panel was the bare minimum that we would install, regardless of how small a house was. Reason being was to make sure the homeowner had sufficient capacity for whatever could conceivably come up. Picture this for example; The water heater is calling for heat, the oven is on, the HVAC just kicked in, someone is vacuuming the carpet, and you're making a blender full of margharitas while your father in law is running a tablesaw out in the garage. And I forgot to mention that the refrigerator just kicked in because you had the freezer door open too long. You'd be surprised at how much current (amperage) is required for all that. Gotta figure for worst case! :wink: All that stuff could happen even in a small house. And... just because it says 100amps, doesn't necessarily mean that all that is at your disposal. Panel ratings and overcurrent protection are figured for a 25% safety margin.... this helps to take care of various things like current inrush when you turn on an inductive load, HVAC for example.

dmaceld 07-25-2007 01:31 PM

Upgrading to a 200A service will unquestionably require you redo the entire service entrance.

Consider this. Put in a 200A box with a 150A main breaker. You may be able change out the wire in the service conduit to a larger gauge for 150A and still be within the code allowance for conduit fill. If your house and service is fairly old the wire probably has thicker insulation than newer wire does, and on rewiring I believe you are allowed a slightly greater conduit fill than on new work. You may not even have to replace the meter socket.
Not the cheapest way to go necessarily, but not the most expensive either.

Moving the box to the interior is a good idea. But this does mean moving all the circuits to the inside. That in itself may be a show stopper.

150A service isn't standard, but 150A main breakers are readily available and will fit in a 200A box. What you cannot do is upgrade the main breaker in your existing box to carry the load of a new subpanel unless the box is rated for a larger main.

msdosfx 11-16-2009 05:48 PM

125 amp
I am doing the same thing very soon to a house I bought to add some 220 breakers and additional lighting, outlets etc. It is my understanding that, depending on your service feed you could get a 125 amp load center with 32 spaces by replacing your existing 100amp load center with a QO132L125G.

You just want to make sure that your breakers match the load center and that you will not be drawing too much power in which case you would definitely want to change 200 amp service.

Scuba_Dave 11-16-2009 05:54 PM

This thread is over 2 years old & the original poster hasn't been back in almost 2 years

All times are GMT -5. The time now is 06:36 PM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1