Entire 2nd floor wired to one 15A breaker!!!

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  #1  
Old 06-08-05, 10:55 AM
VeeReihen6
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Entire 2nd floor wired to one 15A breaker!!!

OK, i've asked a few people around the office here (one who used to be a contractor, another who used to do Home inspections) and all say that this is pretty abnormal:

The entire second floor of my house seems to be wired into one 15A breaker (except for the 2 bathroom GFCI outlets).

That's about 12 outlets, and one attic fan. All lamps on the 2nd floor are plugged into outlets, so they are on the same circuit, as is a PC, and 2 TV's.

It seems very bizarre to me that they would all be on one 15A breaker. I've tried to put an air conditioner up there, but it keeps dimming the lights and/or tripping the breaker when the compressor kicks in.

Is it normal to have an entire 2nd floor on one breaker or did the builder cut some corners? The house was built in 1985.

Any suggestions/ideas? Thanks in advance for any help.

-Costas
 
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  #2  
Old 06-08-05, 11:25 AM
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I guess it would depend on what your "entire second floor" is made up of. Are there a couple of bedrooms and maybe some other rooms?
 
  #3  
Old 06-08-05, 11:26 AM
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It isn't necessarily wrong for all of that area to be on one 15A circuit, but I'd say the builder cut corners without a doubt. There certainly isn't enough capacity for an A/C on that circuit.

How many square feet is the second floor?

It would be a good idea to leave the existing circuit as-is, and add a couple new circuits where you need more power. For example, run a new 20A circuit to the window where you want the A/C. Perhaps run one for the PC and office machines.
 
  #4  
Old 06-08-05, 11:26 AM
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The use of the word normal is somewhat irrelevant in this situation. The electrician calculates the expected load on each circuit. This is done taking several things and known standards into consideration. Having the lighting circuits and receptacles on the same 15 amp breaker for an entire living level may be perfectly fine, maybe not desireable however. The one thing that I dont like about your situation is the attic fan on this circuit. A 15 amp circuit has 1800 watts of power available. Typical attic fans use about 800 to 1000 watts. This doesnt leave much to operate the accessory equipment. So with the attic fan running, a few lights on, the pc on and the tv's you pretty much have this circuit "maxed out". If I would suggest anything I would say try to run a new circuit for the attic fan. The other disadvantage is if the breaker trips, as this exists, you are left in the dark since all lights appear to be on this circuit other than the bathrooms. good Luck
 
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Old 06-08-05, 11:37 AM
VeeReihen6
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ok, thanks for the quick replies!! I'll try to answer the questions as best as I can:

I guess it would depend on what your "entire second floor" is made up of. Are there a couple of bedrooms and maybe some other rooms?
3 bedrooms, 2 full baths, 1 walk in closet. (Plus the roof fan)

How many square feet is the second floor?
approximately 800 sq ft


the other disadvantage is if the breaker trips, as this exists, you are left in the dark since all lights appear to be on this circuit other than the bathrooms.
yes, all the lights (including the 2 lights in the baths....forgot about those) are on this circuit.

So the general consensus would be to add another circuit, either for the attic fan, or the AC?

I know I'll probably get yelled at for this, but what are the odds that the wiring could handle a 20A breaker? It would have to be 12gauge wire right?

Thanks again everyone!

-Costas
 
  #6  
Old 06-08-05, 11:43 AM
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You definitely need a new circuit for your A/C.

You have called your fan both an "attic fan" and a "roof fan", so I'm not quite sure what it is. Different types of fans use considerably different amounts of power. Does the fan mount in the roof and blow attic air outside, or does it mount in the ceiling and blow inside air into the attic? If the latter, is it a 24", 30" or 36" fan?

If it mounts between the attic and the outside, you may not need a separate circuit for it. When in doubt, check the specs on the nameplate (although that would require you to climb up into the attic to do so).
 
  #7  
Old 06-08-05, 11:48 AM
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Originally Posted by VeeReihen6
what are the odds that the wiring could handle a 20A breaker?
I'd say zero. Yes, it would all need to be 12 gauge.
 
  #8  
Old 06-08-05, 11:53 AM
VeeReihen6
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Originally Posted by John Nelson
You definitely need a new circuit for your A/C.

You have called your fan both an "attic fan" and a "roof fan", so I'm not quite sure what it is. Different types of fans use considerably different amounts of power. Does the fan mount in the roof and blow attic air outside, or does it mount in the ceiling and blow inside air into the attic? If the latter, is it a 24", 30" or 36" fan?

If it mounts between the attic and the outside, you may not need a separate circuit for it. When in doubt, check the specs on the nameplate (although that would require you to climb up into the attic to do so).
oops! sorry about that, its a roof fan that blows air from the attic to the outside. I believe that its either a 24" or a 30". I can check tonite.
 
  #9  
Old 06-08-05, 01:07 PM
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Actually I think the term "attic fan" refers to a fan installed in the roof of the attic. In which case I was refering to fans installed in the floor of the attic (ceiling of the house) probably more acurately called "whole house fans". So for the sake of accuracy I was incorrect in my terminology and should have used the latter.
Technically the standard for lighting circuits is 3 VA (watts) per square foot. so one 15 amp circuit would be considered good for 600 square feet. So you could argue that you should have had 2 lighting circuits.
 
  #10  
Old 06-08-05, 01:57 PM
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I would say that since you never had any problems blowing the breaker UNTIL you started using the AC there was no problem at all with the one breaker for the second floor.
It is pretty common to need a new circuit when an AC is installed.
 
  #11  
Old 06-08-05, 07:18 PM
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15 amp for whole floor

i am not an electrician but i thought there was something like a 15 amp breaker would handle around 1200 watts (electrician here would know for sure) so if your second floor never used more than that..you would be safe...how ever since the time your house was built things have changed a lot...blow dryers in the bathroom ..and other heavy electrical users that may be on at the same time..as the fellow in the last post stated...for sure a new lne for AC...and if it was my house i would try and add a new line to the bathroom and maybe a few of the easier outlets to get at

years ago i lived in a one floor home...2 15 amps did the whole house..was probably fine when you made toast on the wood stove and light bulbs were 40 watts..no computers...hair dryers..electric vacumes or high amp battery boosters..lol
 
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