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Wire size for new construction home

hunterguy86

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Meter can and main panel are on a power pole. I will be pulling 200 amps from the pole to the house in an underground feed in conduit. Planning 3/0,3/0,3/0 thwn. What size ground? Is there a single cable option for this? I don't want aluminum.

The contractor wants an exterior panel for all 240 loads and an interior sub panel for all 120 stuff. He wants the interior panel feed with 125 amps. I assume that should be 1/0 ser?

What is a code compliant way to pass wire from interior stud space to an exterior panel? Siding is all Hardie.

Wire will be 10/3 for dryer and hot water heater, 6/3 for stove and a/c and wire to interior sub panel.

Thanks for the help.


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hunterguy86

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Main panel on the pole. Current beakers feed shop, storage shed, and an outlet on the pole for construction crews. The outlet will be removed once construction is complete. Shop and shed are square d homeline. House will be the same.


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larry_g

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I would suggest that you reconsider removing the outlet. I have one at my box and found it to come in handy a couple of times.

lg
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hunterguy86

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I would suggest that you reconsider removing the outlet. I have one at my box and found it to come in handy a couple of times.

lg
no neat sig line



I might leave it. It's wired with #10 thwn to an outlet in a weatherproof enclosure. It was fed with a seimens 20 amp breaker. The framing crew asked for it to be swapped for a 30. The only 30 on hand was a square d, which I am told, is ul listed for multiple brands. Regardless, once the feed is made to the house, that square d is coming out and then seimens breaker is going back in.


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ddawg16

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Personally, I'd prefer just one 200A panel with 20 or more spaces. It will give you any mix of 240 and 120 you want.

Use a good good panel like a CH...and you can use tandem breakers for even more ckts.
 

American Locomotive

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Personally, I'd prefer just one 200A panel with 20 or more spaces. It will give you any mix of 240 and 120 you want.

Use a good good panel like a CH...and you can use tandem breakers for even more ckts.
Yeah, it seems really annoying to have a "120v" panel and a "240v" panel, especially since the inside panel would be capable of 240v loads anyways.
 

sberry

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The framing crew doesn't get to change the breaker, limited to 20A.
2nd ly, this "contractor" doesn't know wtf he is doing in some sense.
 
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Bert_

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I don't see the point in having the two panels separated from each other. Is the sub panel because you will have more circuits than will fit in a 40 space panel? Why put one outside?

I believe 310.15(B)(7) would allow you to use 2/0 copper for your 200A feeder. It apply's to both services and feeders that carry the entire load of a dwelling. The ground would need to be #6. Depending on the situation you may be able to reduce the neutral also.

I cannot think of a cable that would be suitable for your situation. Individual conductors will be easier to pull anyhow. Any particular reason you do not want aluminum?

I've fed temp outlets for construction with 1p 30A breakers too, It's not correct but for temporary use I don't really consider it a big issue.
 
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Norcal

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I might leave it. It's wired with #10 thwn to an outlet in a weatherproof enclosure. It was fed with a seimens 20 amp breaker. The framing crew asked for it to be swapped for a 30. The only 30 on hand was a square d, which I am told, is ul listed for multiple brands. Regardless, once the feed is made to the house, that square d is coming out and then seimens breaker is going back in.


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No breaker is UL listed for any panel other then same manufacturer as the panel, some but not SQ D, are UL classified to be used in other makes of panel, but without the paperwork in hand saying it's OK it's BS, unless the panel is obsolete, it's always best to use the same make breaker in a panel, A SQ D HOM is never OK in other then a SQ D Homeline panel, Eaton & Siemens both make UL classified breakers for SQ QO panels, & Eaton does make breakers that are UL classified for GE, ITE/Siemens, & others.

If the breakers are tripping for the construction crew, add a couple of additional circuits so the load is spread out a bit rather then oversizing overcurrent devices, it's tripping for a reason.
 

Norcal

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Personally, I'd prefer just one 200A panel with 20 or more spaces. It will give you any mix of 240 and 120 you want.

Use a good good panel like a CH...and you can use tandem breakers for even more ckts.

C-H, now Eaton has two lines, a premium line CH, & the trash line BR, which I call "Zinsco II", in the past they even used Zinsco mains in 150,175,200,225, ampere main breaker panels.

With most residential circuits requiring AFCI's, the use of twin breakers is coming to a end in new construction.
 
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theoldwizard1

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2nd ly, this "contractor" doesn't know wtf he is doing in some sense.

Can you expand on your reasoning for this?

Here is your answer :

If the breakers are tripping for the construction crew, add a couple of additional circuits so the load is spread out a bit rather then oversizing overcurrent devices, it's tripping for a reason.

120V/30A plugs and receptacles are not common,
30367910-b959-41cf-b474-1843e677f2a1_145.jpg

except for the RV industry TT-30 which, I doubt, they would like. Put in another 20A circuit. Spend the money and use a REAL 5-15/20 receptacle.
 

75gmck25

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I think the separation of 220 volt breakers into a separate external panel may be a local requirement in certain parts of Texas, since they used a similar arrangement when I built my house in San Antonio. The breakers for the A/C units, stove and water heater were in an external panel, right next to the meter, and the 120 volt breakers were in a standard panel in the garage.

Someone told me this was a local fire safety requirement, so that they could turn off all the 220 feeds from outside the house, but I'm not sure of the real requirement.

Bruce
 
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Norcal

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I think the separation of 220 volt breakers into a separate external panel may be a local requirement in certain parts of Texas, since they used a similar arrangement when I built my house in San Antonio. The breakers for the A/C units, stove and water heater were in an external panel, right next to the meter, and the 120 volt breakers were in a standard panel in the garage.

Someone told me this was a local fire safety requirement, so that they could turn off all the 220 feeds from outside the house, but I'm not sure of the real requirement.

Bruce

How are you getting "220" and 120 volts?
 

Norcal

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Here is your answer :



120V/30A plugs and receptacles are not common,
30367910-b959-41cf-b474-1843e677f2a1_145.jpg

except for the RV industry TT-30 which, I doubt, they would like. Put in another 20A circuit. Spend the money and use a REAL 5-15/20 receptacle.


I never said use 30A devices, and 30A 125V rated devices are available and common in straight blade and locking configurations.
 
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hunterguy86

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The 30 amp breaker is getting changed today.

Any input on the original questions in regards to wire size and a code compliant way to pass wire from an interior stud space to to an exterior panel.

As far as 2 panels go, that's the common way things are wired here I guess. Every house in my old neighborhood was wired that way. 240 loads in exterior panel and 120 loads in a sub in the garage. The only difference here is my meter is on a pole instead on the side of the house.


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sberry

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I spose this could be required depending on where the interior panel may be, the service on the pole adds a bit to the confusion. I doubt its really due to 240 loads but more indoor and outdoor. Like it is now, feeding outbuildings maybe even a well. If the interior panel is away from where it enters the building it could require an outside disconnect, as you said, if this panel was on the house it would seem logical.
Not sure what I just wrote makes sense?
 

ard

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"The contractor wants"???

I'd say the contractor does what **I** want. And I don't want breakers outside. Period. Unless requred by code or local REQUIREMENT.


I've never heard of this, but I lead a sheltered life....
 

wyliesdiesels

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Meter can and main panel are on a power pole. I will be pulling 200 amps from the pole to the house in an underground feed in conduit. Planning 3/0,3/0,3/0 thwn. What size ground? Is there a single cable option for this? I don't want aluminum.

The contractor wants an exterior panel for all 240 loads and an interior sub panel for all 120 stuff. He wants the interior panel feed with 125 amps. I assume that should be 1/0 ser?

What is a code compliant way to pass wire from interior stud space to an exterior panel? Siding is all Hardie.

Wire will be 10/3 for dryer and hot water heater, 6/3 for stove and a/c and wire to interior sub panel.

Thanks for the help.


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First off, why is it that the contractor wants anything. Isnt this your home? Is he mandated by local code to do an exterior panel?

Youre best bet is to use individual conductors.

May i ask why u dont want to use AL...

If you look at Table 310.15(B)(16) found here you will see that 1/0 AL is too small for 120a load. You will need 2/0...

SER can be used in above ground wet locations so u could surface mount it into the side of the panel or bring it into the back of the panel. Will this outside panel be surface or flush mounted?

However, since u said you have a contractor, shouldnt he be the one to figure all this out? Is he a general or an electrical contractor??

I might leave it. It's wired with #10 thwn to an outlet in a weatherproof enclosure. It was fed with a seimens 20 amp breaker. The framing crew asked for it to be swapped for a 30. The only 30 on hand was a square d, which I am told, is ul listed for multiple brands. Regardless, once the feed is made to the house, that square d is coming out and then seimens breaker is going back in.

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You cant put a 20a outlet on a 30a breaker. That should be changed to a 20a Siemens breaker and another outlet should be added

And SQ D isnt listed for a Siemens panel. No breakers are listed for use in a different brand/make of panel....

There are, however, classified breakers for use in certain different makes of panels. However, the SQ D homeline breaker you have is not classified for use in the siemens panel.

The info u got is wrong. Or may be misinterpreted since Siemens does make classified breakers for use in SQ D QO panels...

Best bet is to use the same brand/make and model of breaker for use in the panel unless its an old panel which obviously doesnt apply to you...

I don't see the point in having the two panels separated from each other. Is the sub panel because you will have more circuits than will fit in a 40 space panel? Why put one outside?

I believe 310.15(B)(7) would allow you to use 2/0 copper for your 200A feeder. It apply's to both services and feeders that carry the entire load of a dwelling. The ground would need to be #6. Depending on the situation you may be able to reduce the neutral also.

I cannot think of a cable that would be suitable for your situation. Individual conductors will be easier to pull anyhow. Any particular reason you do not want aluminum?

I've fed temp outlets for construction with 1p 30A breakers too, It's not correct but for temporary use I don't really consider it a big issue.

Look closer @ table 310.15(B)(7) (which has been removed from the NEC). Its for 3 wire dwelling services and feeders. The OPs dwelling feeder is 4-wire because of the disconnect at the pole so 310.15(B)(7) doesnt apply. He will need to use full size conductors...

As for the 30a breaker on a 20a outlet it could be a big deal especially if the wire is #12 and is feeding multiple saws and compressors...I have seen 20a outlets burn up from near 30a flowing through them. They arent rated for 30a...
 
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wyliesdiesels

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120V/30A plugs and receptacles are not common,
30367910-b959-41cf-b474-1843e677f2a1_145.jpg

except for the RV industry TT-30 which, I doubt, they would like. Put in another 20A circuit. Spend the money and use a REAL 5-15/20 receptacle.

Thats not true. They are commonly available in straight and twist lock versions...My local Home Depot sells them...

Ive installed many L5-30 outlets for UPSs...

The TT-30 is a different blade config than the 5-30....
 

Bert_

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Look closer @ 310.15(B)(7) (which has been removed from the NEC). Its for 3 wire dwelling services and feeders. The OPs dwelling feeder is 4-wire because of the disconnect at the pole so 310.15(B)(7) doesnt apply. He will need to use full size conductors...

I will recheck when I when I can, but I believe it specifically stated "with or without a grounding conductor"

I agree that the table has been removed but the article has stayed mostly the same. Now it just allows you to use a percent of the normal ampacity, which is the same result as what the table gave. Again I will check the exact wording when I have my code book.
 

sberry

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This isn't really such a deal especially with intermittent loads and probably not so much with saws but lots of stuff could be plugged in isn't rated for short circuit interruption with that high of breaker, basically if it comes with a 15 end only rated for 20.
 

Norcal

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Thats not true. They are commonly available in straight and twist lock versions...My local Home Depot sells them...

Ive installed many L5-30 outlets for UPSs...

The TT-30 is a different blade config than the 5-30....

HD does not sell Twist Lock®, they sell locking devices, Twist Lock® is a registered trademark. :bounce: Just had to say that. :)
 
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hunterguy86

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Just to clarify. The 30 amp breaker is gone. It's back to a 20. The wire is #10.

I like the idea of two panels. I want an outside disconnect to kill out the house if needed. I also like the interior sub panel. This will make it easy to set up for generator backup with the square d generator interlock kit. We are very rural here so it would be nice to be able to run the fridge and a few lights in case of emergency off my current generator. I am happy with the two panel plan.

I don't want aluminum. Don't want to mess with the paste and everything else that goes with aluminum. Yes, it's more money. But, I want copper, so copper it will be.

My contractor is a gc. There are no codes and no inspections where I am, but that doesn't mean things don't need to be done to code. Most code was literally written in blood, that's why it exists. I am doing the electric myself to save some coin.




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Bert_

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Look closer @ table 310.15(B)(7) (which has been removed from the NEC). Its for 3 wire dwelling services and feeders. The OPs dwelling feeder is 4-wire because of the disconnect at the pole so 310.15(B)(7) doesnt apply. He will need to use full size conductors...

A lot of the wording I was thinking of has changed in the '14 NEC. That doesn't change anything though since the content is the same, and a little less controversial I think.

That section reads as follows,

310.15(B)(7) FOR ONE-FAMILY DWELLINGS AND THE INDIVIDUAL DWELLING UNITS OF TWO-FAMILY AND MULTIFAMILY DWELLINGS, SERVICE AND FEEDER CONDUCTORS SUPPLIED BY A SINGLE-PHASE, 120/240-VOLT SYSTEM SHALL BE PERMITTED BE SIZED IN ACCORDANCE WITH 310.15(B)(7)(A) THROUGH (D).

(B) FOR A FEEDER RATED 100 THROUGH 400 AMPERES, THE FEEDER CONDUCTORS SUPPLYING THE ENTIRE LOAD ASSOCIATED WITH A ONE-FAMILY DWELLING OR THE FEEDER CONDUCTORS SUPPLYING THE ENTIRE LOAD ASSOCIATED WITH AN INDIVIDUAL DWELLING UNIT IN A TWO-FAMILY OR MULTIFAMILY DWELLING SHALL BE PERMITTED TO HAVE AN AMPACITY NOT LESS THAN 83% OF THE FEEDER RATING.

83% of 200A allows the use of 2/0 copper or 4/0 aluminum.

Please correct me if I am wrong but I believe this describes the OPs situation to a "T"




I don't want aluminum. Don't want to mess with the paste and everything else that goes with aluminum. Yes, it's more money. But, I want copper, so copper it will be.
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It's your money so do whatever makes you feel good, just don't make it sound like it's more hassle to install aluminum. While it is good practice to use antioxidant paste it is not required in most cases. Even with that minor inconvenience, aluminum is lighter, easier to pull and bend than copper. I'm not trying to convince you to change your mind I just don't appreciate you attemting to cast a bad light on aluminum wire. There are positives and negatives to all wiring methods.

My contractor is a gc. There are no codes and no inspections where I am, but that doesn't mean things don't need to be done to code. Most code was literally written in blood, that's why it exists. I am doing the electric myself to save some coin.

The NEC applies to the whole country even if there is no inspection.

As far as code's being written in blood (experience) that's debatable. But this isn't the time or the place :eyecrazy:
 
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