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Old 01-04-2010, 11:17 PM   #46
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Quote:
Originally Posted by codeone View Post
Marc, I try to err on the side of safety. Used his largest heater at 125% then added 1.5a for each outlet either rec or lighting. Not necessarily the best way. Mel

That what I thought so that why I did double check my figures plus your figures due I am used to 180 Va rating per dupex recetpales { The French codes are diffrent they go 200 or 240Va depending on it run }

Merci,Marc
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Old 01-05-2010, 12:35 AM   #47
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It is not likely that you will be able to use a 100 amp branch breaker in a 100 amp service panel. Almost all residential loadcenters have a bus stab rating for branch breakers or a maximum branch circuit breaker. In most 100 amp panels it will be 70 amps per bus stab. Meaning If I install a 70 amp double pole breaker to feed a sub panel from my 100 amp panel then I cannot have any breakers adjacent to it. Or if I have two single poles adjacent to each other they cannot have a sum greater than 70 amps as shown in the diagram..
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Old 01-05-2010, 03:55 AM   #48
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Yes It does not always available in most areas because of cost.
Also that is in the 60 degree column in the 2008 NEC.
Some places still use the 2005 or earlier which did not have this requirement.
The code book that was next to my computer last night was the 1999 NEC and it's in there.

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Old 01-05-2010, 04:03 AM   #49
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Again my appologies. Your load is approx 55A. So if you use a true 100A

For 100A using SER cable you would need a #1 cable for copper if you are using alumn it would need to be a 1/0.

You would need to run pipe to use the #3
You could also run #2 SER copper and install a 90A breaker to have room for your expansion.
Why can't I use #2 copper for 100 amps? Check 240.4(b).

Mark
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Old 01-05-2010, 04:43 AM   #50
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I have a gas furnace,gas water heater,gas dryer,gas stove and ac. house is about 1500 sq feet and 105 years old. I just had that 100 amp service installed when i had the ac put in should of went for the 200 amp. What needs to be done to go to 200 amp i realize a new panel?

Last edited by Kurt1968; 01-05-2010 at 04:51 AM.
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Old 01-05-2010, 05:09 AM   #51
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The code book that was next to my computer last night was the 1999 NEC and it's in there.

Mark
I did a little more research on the need to use the 60 degree restriction with SE cable.

1996 - Use 60 degree
1999 - Use 60 degree
2002 - Not restricted
2005 - Not restricted
2008 - Use 60 degree

I'll need to do more digging to determine the cause of the reversals.

Mark
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Old 01-05-2010, 05:15 AM   #52
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Here's the text of the change from the 2008 ROP.

(338.10(B)(4)(a))
__________________________________________________ __________
Submitter: James M. Daly, General Cable
Recommendation: Delete the phrase “excluding 334.80” and change the
comma after “Article 334” to a period.
Substantiation: When Type SE conductors are used for interior wiring, as a
replacement for Type NM cable, the ampacity of the conductors should be the
same as permitted for NM cable since the insulations used are the same both
NM and SE conductors.
Panel Meeting Action: Accept
Panel Statement: This action will modify the action taken on Proposal 7-84.
Number Eligible to Vote: 14
Ballot Results: Affirmative: 14

Mark

By the way, it surprises me that this proposal was accepted since the insulation in SE cable in NOT always the same as NM cable. NM cable is always THHN/THWN. From Southwire, their SE cable has either sunlight resistant Type XHHW-2 conductors or Type THHN/THWN.

Last edited by busman; 01-05-2010 at 05:55 AM. Reason: More info
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Old 01-05-2010, 06:10 AM   #53
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The new 100 amp panel i had installed. Is a 20 space panel I think and theres only 8 spaces used. My whole up stairs is on one breaker. So I have 12 empty spaces.

Last edited by Kurt1968; 01-05-2010 at 06:22 AM.
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Old 01-05-2010, 07:41 AM   #54
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The new 100 amp panel i had installed. Is a 20 space panel I think and theres only 8 spaces used. My whole up stairs is on one breaker. So I have 12 empty spaces.
Sounds like you do not have anything heavy in electric use then ?

Without knowing exactly what you have I would install a 60a 240v sub
I would use a 100 20 space main breaker panel & feed it with 60a
Use THWN in conduit with #6 copper wire you can use a 60a breaker

You would need to verify if your area requires the use of conduit & if they require metal conduit
My understanding is Chicago area requires conduit (metal ?)

You could also run a 50a panel & use #8 wire again using copper TWHN wire



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Old 01-05-2010, 09:21 AM   #55
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My only electrical stuff I have would be the fridge,microwave,dishwasher clothes washer and eletronic stuff like tv,computers. I also have central air. Can i get a 60 amp subpanel still all i can find is 100 amp panels. The only thing new i would be adding is the electric baseboard heaters. Everything else in the attic and the upstairs is already there just need to rewire them. So i should be ok by just adding the 2 baseboard heaters. So just need to add a 60 amp breaker to the main panel and wire the subpanel to that.

Last edited by Kurt1968; 01-05-2010 at 09:27 AM.
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Old 01-05-2010, 09:58 AM   #56
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Kurt

If you have 12 spaces left in your new 100 amp panel in the basement why are you running a sub-panel in the attic? You still have to get a feeder to that sub-panel .. it would not be any worse or difficult to get 3 branch circuits (one for heating) to the attic using your existing service panel. My only suggestion would be to change your baseboard heat to 240 volts this will reduce your amperage and likely allow you to install more heating up in your attic as a benefit. I don't think you will be happy with 120 volt baseboards.

However if your set on a sub-panel and sticking with 120 volt loads operated out of that sub-panel then I would suggest a mlo 100 amp 6/12 circuit sub or similiar. You cannot feed it 100 amps though and you don't need 100 amps..... so just run a 60 amp breaker in your service panel using #6 copper nm-b cable or a 70 amp breaker if THHN in conduit if that is required in your area. Be sure to check your existing 100 amp panel for any bus stab restriction or maximum branch breaker. Look to the "sticky" on this website that shows some links to sub-panel installations and find the one that matches your situation .... which would be a sub-panel in the same dwelling with the service equipment. Your going to be running a feeder with 4 wires (H-H-N-G) and isolating the neutral and ground in the sub-panel. Be sure you understand how to do this.. or ask us. This configuration will allow you to operate both 120 and 240 volt loads from the sub-panel.
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Old 01-05-2010, 12:36 PM   #57
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No i'm not set on anything jsut trying to get ideas. So I would need one circuit for the heater ,one for lights and one for outlets. Stubbie what size wire do you suggest for those circuits.
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Old 01-05-2010, 01:21 PM   #58
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Do one home run with 14/2G for lights. One homerun with 12/2G for receptacles and one 12/2G for your baseboards if your going with 240 volt baseboards. They are very easy to wire using a double pole breaker you just don't have a neutral and the big fat wire it takes for 120 volt baseboards. You can run 3840 watts of heat on one 240 volt 20 amp double pole breaker and 12 awg wiring. Here is a link to a very good baseboard with lots of nice options. Figure about 10 to 12 watts of heat per square foot for a well insulated room. If you are going to have poor insulation and lots of heat loss might want to figure 15 to 18 watts of heat. If you want more capacity for heat or anything else then just run another 12/2 g to the attic and terminate it in a jb for future use.


There might be an issue with voltage drop effecting wire size but I doubt you are a long way from your service panel but might give us that information just in case.

Use the first link to navigate the site ... you should be able to answer all your questions and view videos of installation. Ask us if you have questions. They also have a sizing chart under the heat selection link.

http://www.cadetco.com/show_product.php?prodid=1004
http://www.cadetco.com/support/specsheet/1004.pdf

We should have you all lined out in short order while the other two guys are continuing to determine when they changed the requirements of ser cable to 60 C.....
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Old 01-05-2010, 01:55 PM   #59
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My only thought is that you indicate that you are going to rewire more
Do you have 2 floors & the attic ?
Or the attic area is part of the 2nd floor ?

You stated you have knob & tube (spool) wiring that you will be eliminating
With 12 spaces left you will be using 4 for the attic area without a sub-panel

With an older house it is probably not up to code
Code today requires:
2 circuits for the kitchen counter-top
Dedicated run to the bathroom(s)
Dedicated circuit to the laundry area
While you are not required to bring anything up to code when you remodel you (usually) are

So take into consideration how many more circuits you may want to run
And how many will need to go to the attic/2nd floor
Running subpanel = pulling 1 run up to the attic (you do use a 100 panel & feed with 60a)
VS running the three circuits you want

Just want to make sure you consider the options



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Old 01-05-2010, 02:18 PM   #60
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Quote:
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Why can't I use #2 copper for 100 amps? Check 240.4(b).

Mark
Mark,
Under this section (which I sometimes forget, we see so many things in the field) you could use the #2 copper. There has been great discussions on wether a Panel is a device or not. A device and a panelboard have seperate deffinitions is one reason why. This could be a good discussion sometime. However not here at this time weve caused enough confusion.
We need to stick to the issue at hand.
Thanks Mel.
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