circuit breaker boxes

[Nate Nagel]

My bedrooms are all on the same circuit, and the only other room on that circuit is the bathroom. I would like to split that off anyway so in my case I really don't care. At the same time I do that I will probably pull another homerun from the 2nd floor back to the breaker panel so that I can split the bedrooms into two circuits (yes I have another AFCI standing by.)

I actually have a 40 ckt. 200A panel in my house, but it only has 20 full sized breaker spaces, so there's lots of half height breakers in there (now.) If *I* were the guy doing the upgrade, I would have spec'd a larger panel, but that's water under the bridge.

I'm digressing a bit, but sort of on the same topic, I have a question regarding the wiring between my house and my garage. The house's breaker panel has a 100A 2-pole breaker in it, which feeds the subpanel in the garage. The other end of that wire connects to a 100A 2-pole breaker in the sub-panel. That just seems weird and redundant to me. Is this common practice, and what is the reason for it? Or did someone improvise "on the fly" and what would be the right way to do it?

nate

RBM wrote:

[Gerald Newton]

Always check with your utility company when doing an upgrade. If you have been getting by with a 60 ampere service you probably do not need more than a 100 or 125 ampere upgrade. Per Code Section 220.83(A) for upgrading an existing service for additional loads where air conditioning and electric heat are not added the following is used: First 8 KVA of load at 100 per cent Remainder of load at 40 per cent Where load is 3 VA/ sq.ft or for you 3 x 1240 = 3720 VA Small appliance load = 3000 VA Household range (usually 8000 VA) All other appliances pemanently connected (like a boiler motor or bathroom fan) or fastened in place (dishwasher) at nameplate ratings. (For good measure just add 3000 VA here.)

This gives 3720+3000+8000+3000 = 17720 First 8000 VA at 100 per cent + 0.40 x (17720-8000) = 11888 VA

11888 VA / 240 volts = 99 amperes So using this calculation a 100 ampere service would suffice.

If you are adding or have air conditioning and electric heat or are planning to add a two car garage and a shop, etc upgrade to a 200 ampere service.

[RBM]

The breaker in the main panel protects the wiring to the garage. If the garage is detached, it's required to have a disconnect in it. If it's attached, the electrician probably got a good deal on a panel with a main breaker

[Nate Nagel]

The garage is detached; the subpanel doesn't have a main breaker, it's just fed through a regular 100A breaker. The home inspector didn't seem to think it was weird, except for the fact that the ground terminal strip was mounted too close to the front of the panel.

nate

RBM wrote:

[RBM]

That's fine, he just back fed a main lug panel

[CJT]

It sounds to me like you're using a lot of electricity for such a small house; is it all-electric?

[CJT]

I'm of the "if it ain't broke, don't fix it" school. The OP might find the upgrade requires bringing everything else up to current code, which could get very expensive. A bit of conservation could pay big dividends.

[CJT]

In other words, it's only money ...

[CJT]

Cook and heat water with gas and save money.

[CJT]

What electrician will be willing to bring something "closer than it was" to code?

[Nate Nagel]

I didn't say I was a professional. But the only items not to code that I'm aware of right now are the lack of a dedicated 20A circuit to the bathroom, one kitchen counter outlet that's on a 15A general lighting/receptacle circuit, and a few remaining receptacles that aren't grounded. I'm picking away at those issues, but my point was I don't particularly see the point of saying "well, it still won't be perfectly code compliant for new construction, so why bother?"

nate

[CJT]

There's no indication the OP would be willing to make the changes on their own. So an electrician will be involved. My question stands.

[Tekkie®]

What do you mean by this? You pay for usage.

[HeyBub]

Wrong question. No one here is going to consider a 125A box when a 200A box is the standard, costs no more to install, has plenty of room for expansion, and is a negligble increase in price over a 125A.

[HeyBub]

A few hundred dollars? Try $65.

Here's two kits:

The 200Amp kit is $125.00 and comes with 14 breakers.

Here's the corresponding 100A kit for $60.00 (with a mere 5 breakers)

Mind you, these are RETAIL prices.

[RBM]

Where I live, and work,(as an electrical contractor) electrical services, regardless of their amperage, don't install themselves, and while the price of installing a service is determined not only by the equipment being installed but also by particulars of each job, in general a 200 amp overhead service costs about three hundred dollars more than a 100 amp service. We also don't have a "standard" service, most new houses do have 200 amp services installed, but the NEC requires a minimum of 100 amps, and for a very small house with gas cooking 100 amps should be more than adequate

[Doug Miller]

That's silly. You pay for the electricity you use, not for the capacity of your service.

It won't be. 200A panels are more expensive than 125A panels, and 200A service requires heavier (and therefore more expensive) service entrance conductors. The *labor* should be pretty near the same, but the

*materials* will definitely be more expensive for 200A.

Missed the part about the home being only twelve hundred square feet, didja? 200A service is a nice feature to have, but having "only" 125A service on a home that size shouldn't have much, if any, impact on resale value. At most, I'd expect the homeowner to recover the extra cost at resale, not realize any profit from it.

No, let the *electrician* do that.

[zxcvbob]

If the garage panel has 6 or less breakers (a two-pole breaker with the handles tied only counts as one), it doesn't need a main disconnect.

Best regards, Bob

Nate Nagel wrote:

[Doug Miller]

Now add in the difference between 2/0 copper (or 4/0 aluminum) vs. #2 copper (or 1/0 aluminum) service entrance conductors. Don't forget that 200A service requires a heavier grounding conductor, too.

[Doug Miller]

The 200A service will require larger conduit for the service drop, too. And a correspondingly larger rainhead.

Not to mention... bending 4/0 cables inside a meter base is a cast-iron bitch.