Breaker Panel Configuration


  #1  
Old 02-28-04, 06:13 AM
carlschnurr
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Breaker Panel Configuration

I have a Federal Pacific 100A electrical panel in my 2000sq ft home. It has about 40 knockout for breakers.
On the panel it states that the total of all the breakers should not exceed 300A.

It appears that the original configuration had about 320A.
Including 2x40A breakers for my electric oven.

Since then, air conditioning and other breakers were added to increase this to about 420A.
Some of these appear unnecessary.
An individual 15A breaker was installed for a Jacuzzi in the bath.
An individual 15A breaker was added for electricity to the garage.

I'm in the process of installing a laundry room which would contain a fridge, freezer, gas dryer and washer and an outlet which might be used for ironing. My gut is that these should be on 2 circuits. Additionally, while I'm renovating I want to have the provision to convert part of my basement into a small apartment, so I need to do electrical work in the pannel anyway.

My questions are

1) Should I be installing a "pony" box for my main panel?
and how urgently is the req'd?

2)Do I need 2 circuits for my laundry room.
Do I really need 2x40A breakers for an electic oven, and
more generally, how do I rationalize how many lights/outlets go on a circuit.
 
  #2  
Old 02-28-04, 08:21 AM
R
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Wow, you are asking a lot of questions.

Some background first. Generally speaking, it is not the sum of the circuit breakers that is important, but rather the expected load at any one time. With a 100 amp main breaker, you cannot fraw more than 100 amps at any one time before the breaker trips. So generally speaking the sum of the breakers is not important.

However, manufacturers directions on a panel must be followed for your installation to be code compliant. If the manufacturer indicates that the sum of the breakers must not exceed 300 amps, then to remain code compliant you must follow that.

I would do a load analysis of your home and the expected current draw. I am thinking that it may be time to upgrade your service to be 200 amp service.

You haven't indicated if the items in your laundry room will be new loads or just relocated from other parts of the house, or perhaps some of each. However, the loads you are talking about adding are significant loads.

Further, there is the issue of Federal Pacific circuit breaker panels. Certain types have problems that have been documented. I'm not sure if your panel is one of these or not. Some electricians recommend replacing any Federal Pacific panels just to be safe.

I recommend that you perform, or have performed, a load analysis to see what size service you really need. If you need a larger service (200 amp) then you should replace the entire panel.

I would recommend speaking with several different electricians and obtaining recommendations from them. You may want an electrician to do some of the work, and then do the rest yourself, or you may want an electrician to do everything.

To answer your specific questions.

At the minimum a sub panel is needed.

I think you need at least two circuits for your laundry room. A refrigerator, freezer, washer, dryer and iron are too much load for a single circuit. Probably too much for two circuits.

Your electric oven needs 220 volts. This implies a double pole breaker, so that 110 is drawn from each half of your incoming service. Is this what you mean by 2x40 amp breaker, or do youe mean two separate double breakers? Two separate 220 breakers may be needed if your electric oven is actually two separate ovens.

The number of lights and receptacles on a circuit is unlimited for general circuits. Certain locations have special requirements, and those locations include kitchens, bathrooms and laundry rooms.

For general circuits, you don't want to exceed 80 percent of the circuit current rating.

For lighting, simply add up the maximum rating of the fixture. If the lights can have 100 amp bulbs, then you would not want more than 14 of these on a 15 amp circuit. (15 amps * 120 volts = 1800 watts. 1800 watts * .80 = 1440 watts. 14 * 100 watt light bulbs = 1400 watts.)

Receptacle outlets are somewhat trickier. Other than for the special locations, try to anticipate the load. Bedrooms may have a hair dryer or curling iron, plus several low wattage appliances. However, a window air conditioner is a special case. You may want to run tools (table saw, grinder, drill, etc.) in a garage or unfinished basement.

Just about everyone has a different formula, so I won't state any here. Just remember, it is easier to add more circuits during construction then it is to split curcuits or add new ones once construction is finished.

Good luck!
 
  #3  
Old 02-28-04, 09:40 AM
u2slow
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My house sounds similar...

I have a Federal 100A main with 26 spaces used (32 max) and the house is about 2000 sq ft. I fed my basement suite with a 60A subpanel. Electric ranges. Separate laundry as well (both electric dryers fed from main panel). I also have a 40A subpanel in my attached garage for lights, plugs, and a 240V compressor. The house is heated with gas, but I have a large electric water heater.

My main panel seems to have all the original decals and markings, but I can't find a limit on the combined breaker total. I'm at 645A

I don't have any problems with breakers tripping. I wish I had a clamp-on ammeter to see what I was pulling on a 'good' day

I want to add electric heat to a couple of rooms, and bring power out to a detached garage. My gut says I'm maxed out, so I'm installing to a 200A service in the attached garage. Then re-feed the house, suite, and attached garage from there.
 
  #4  
Old 02-28-04, 05:42 PM
J
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You need to perform a demand load calculation. If you go HERE You can go though it. This will tell you what size panel you should have.
 
  #5  
Old 02-28-04, 06:54 PM
rbad
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Hey guys.... New panels/breakers are really inexpensive.
If you are doing the work yourselves, the cost would probably be under a few hundred bucks depending upon the brand of new equipment. (I happen to LOVE the Square-D QO line, but anything is better than FPE)

If you have the aptitude, I would most DEFINITELY remove the Federal Pacific panels.


Just my $.02.
 
  #6  
Old 02-28-04, 09:26 PM
u2slow
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Originally posted by rbad
Hey guys.... New panels/breakers are really inexpensive.
I'll vouch for that. The panel kits that come with main breaker and several branch circuit breakers are an exceptional value. The kit I bought was actually cheaper than a bare panel and main breaker purchased separately.


I happen to LOVE the Square-D QO line, but anything is better than FPE ... DEFINITELY remove the Federal Pacific panels.
I like Square D's QO line as well. I long for the day when I can finally remove my FPE panel and toss it across my driveway - burnt busbars and all
 
 

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