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Aluminum wire

unvago

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My electrician is recommending #6 Aluminum wire to feed a new 100 sub panel from my house 200 amp main.
The total run is 100 ft. Is #6 ok?
 
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Pat

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I agree with Charles. Also I see where you want to run it to a new 100 amp panel. For certain you are going to want to meet the ampacity rating for the new panel. Just curious as to what equipment you may have running at the same time. I am sure he recommended aluminum because of the difference in price between that and copper, but there may be times when the # 6 aluminum would not be able to safely deliver a continuous draw you would be asking it to do. You may want to check out some ampacity charts, or find another qualified electrician.
 

nate379

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I guess mine nor the power company don't know what they are doing either because I have #4 aluminum wire for my 125 amp service.
 

tfi racing

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My electrician is recommending #6 Aluminum wire to feed a new 100 sub panel from my house 200 amp main.
The total run is 100 ft. Is #6 ok?

Electrician,huh?Time for your guy to find a new line of work...#2 is the minimum,larger for that distance definitely wouldn't hurt.
 

mrb

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I guess mine nor the power company don't know what they are doing either because I have #4 aluminum wire for my 125 amp service.


two entirely different things. Nothing the power co does is regulated by the NEC.
 

walrus

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I guess mine nor the power company don't know what they are doing either because I have #4 aluminum wire for my 125 amp service.

Unless thats the wire coming from the pole to your service mast, your electrician is clueless
 

Aceman

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The total run is 100 ft. Is #6 ok?

No. Like said above, this guy doesn't have a clue. Plain scary...

For certain you are going to want to meet the ampacity rating for the new panel.

Why? I run 60 feeders to 125 amp subpanels all the time, just for the extra spaces.

#2 is the minimum,larger for that distance definitely wouldn't hurt.

If you're talking aerial wire, then yes. In a conduit, no.
 
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unvago

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Thanks for all the input, I was sure that #6 was too small.
The cost for 100' of copper is way too much, I will go with Aluminum
 

mrb

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since your 'electrican' suggested #6al, i am concerned about the rest of what he is doing. Make sure 4 wires are run, not 3, that URD, USE, etc cable types that are for underground only arent run into a building, that the panel in the garage has neutral and ground seperated, that the garage has the required ground rod(s) if detached, that the garage panel has a main breaker or disconnect if detached, etc.
 

nate379

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There are no hung wires in the newer areas around here because it's windy and trees/ice knock everything down.

The wires that comes from the power box by the street to the house and then the wire from the main panel to the breaker panel in the garage is all 4 gauge aluminum.

Unless thats the wire coming from the pole to your service mast, your electrician is clueless
 

nate379

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The logics on using #4 doesn't make sense to me either, but that's what is there and I have to think that the electrician wouldn't come up with something that isn't to code and also get it passed by the electrical inspector.

I don't know if it's figured that a person won't be pulling more than x amount of amp and that's why it's ok, I don't know. The highest electrical load in the house would be my welder actually since the stove and clothes dryer are gas.

Home inspector I got was kinda a waste too.

Pulled the panel off and I was like.. hmm.. I didn't realize that you could use aluminum wire for the mains. He was like, aluminum, where do you see that?

I show him and he said that is something he never even noticed. :wtf: I asked if I could see his code book to look up if #4 could be used even and he didn't have a book.... yeah....

Its a code violation, plain and simple

I have CAT 5 in the garage as well as cable though I don't think I will ever use it. I don't have a phone and the TV is in the living room.
 
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unvago

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MRB,
My installation will include pulling the wires through the house attic from the main panel, down a wall, then underground to the new garage.
Thanks for the infor on the number of wires.
 

mrb

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MRB,
My installation will include pulling the wires through the house attic from the main panel, down a wall, then underground to the new garage.
Thanks for the infor on the number of wires.

are you putting it in pipe, or using a cable?
 

DAinTN

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Hey fellows, ive been fololwing this thread with great intrest as i am doing exactly the same thing ,running 100' with aluminum wire. I also have a friend who is an electrician and he said i would be better off setting up for 200amp service while im putting it in even if i just used it as 100. he suggested 4/0 4/0 4/0 with 2/0 ground wire. i assume this is different from the #6 and #4 you all are discussing and i have plenty as far as wire size goes....thanks in advance for any reply
 

ArthurPE

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Hey fellows, ive been fololwing this thread with great intrest as i am doing exactly the same thing ,running 100' with aluminum wire. I also have a friend who is an electrician and he said i would be better off setting up for 200amp service while im putting it in even if i just used it as 100. he suggested 4/0 4/0 4/0 with 2/0 ground wire. i assume this is different from the #6 and #4 you all are discussing and i have plenty as far as wire size goes....thanks in advance for any reply

4/0 (Al) is too small for 200A, it's only good for 180A
you need at least 250 MCM, which is preety unwieldy

I'm not sure what the grounding conductor should be but I'm guessing 6 for Cu, 4 for Al...i don't have the NEC at home...

100A iirc is #8 Cu/#6 Al
it's based on CB size
 

ArthurPE

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isnt 4 too small to be allowed to parallel?


what's allowed and what's done are 2 different things...
if the guy is advising #4 for 100A, who knows what he'll do?

as far as too small, I'm not sure...I guess it depends on what the feeder CB and panelboard MCB's lugs will accept...good question

just checked, you're right >=1/0 Al or Cu
 
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Aceman

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he suggested 4/0 4/0 4/0 with 2/0 ground wire.

That's fine, but I would suggest 4/0 4/0 2/0 "Sweetbriar" for your service. Since it's a service, there are only 3 wires, no ground.

4/0 (Al) is too small for 200A, it's only good for 180A
you need at least 250 MCM, which is preety unwieldy

240.4(B) says I can go up to the next overcurrent size(200 amp) provided the calculated load isn't over 180 amps. He said he really only needed a 100 amp panel, so we're definitely in the clear.

isnt 4 too small to be allowed to parallel?

Yes, 1/0 is the minimum for paralleling phase or neutral conductors.310.4
 

DAinTN

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Thanks Aceman and everyone for the replys. I do have a 200amp box im feeding to in the garage but i honestly dont need it ,my amp load will never go over what a 100 amp box would have done. the only reason i did was for possible future expansion which in all reality i still would not need a 200 amp but its nice to have too much room now instead of wishing for more later. i guess im the king of overkill . lol thanks again everyone.....
 
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unvago

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The run through the attic will not be in conduit, only the portion going underground from the house to the new garage.
Roughly, what is the difference in price between #6 and #2 aluminum?
 

mrb

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The run through the attic will not be in conduit, only the portion going underground from the house to the new garage.
Roughly, what is the difference in price between #6 and #2 aluminum?

you cant run loose wires through your attic, so that will need to be a cable, or in conduit.
 

ArthurPE

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240.4(B) says I can go up to the next overcurrent size(200 amp) provided the calculated load isn't over 180 amps. He said he really only needed a 100 amp panel, so we're definitely in the clear.


but for the $$ differential, and the fact you're using 200A lugs, why not full rate the system?

otherwise go with 100A or 150A

and doesn't a 'calculated' load have to be performed by an engineer (or under engineering supervision) ?

I'm a firm believer of matching ratings, especially if the $$$ is minimal
 

baugie

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If a fire is caused due to faulty wiring, then the insurance company will not cover the damage. To save a few bucks now, could cost you thousands later........and besides aluminum wire requires annual maintenance....i.e. inspecting ALL connections and lubricating them with a special lubricant on order to prevent corrosion. Also, if aluminum wire is going to be used, it needs to be 2 sizes larger than the recommended copper wire size.
 

Aceman

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but for the $$ differential, and the fact you're using 200A lugs, why not full rate the system?

There is absolutely no reason too.

and doesn't a 'calculated' load have to be performed by an engineer (or under engineering supervision) ?

Do you think an engineer is involved every time an electrician puts a service on a house? No. We have a codebook, we have demand/calculation tables, we are qualified to do a load calc.

I'm a firm believer of matching ratings, especially if the $$$ is minimal

Minimal is interpreted differently for everyone. I wouldn't do it myself, the only reason I'd bump to 250mcm is if the distance was great and I knew they'd be pulling a lot of load, in this instance, this is not the case.

If a fire is caused due to faulty wiring, then the insurance company will not cover the damage. To save a few bucks now, could cost you thousands later........and besides aluminum wire requires annual maintenance....i.e. inspecting ALL connections and lubricating them with a special lubricant on order to prevent corrosion. Also, if aluminum wire is going to be used, it needs to be 2 sizes larger than the recommended copper wire size.

To make a potentially long response much shorter, suffice to say, you don't have a clue.
 

nate379

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In reponse to my deal witht the 4 guage wiring used in the house, is this a big No No?

I would like to have all the info I can and I will go to the builder with it. If this no joke a problem I have a warranty for a reason.
 

ArthurPE

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There is absolutely no reason too.

Do you think an engineer is involved every time an electrician puts a service on a house? No. We have a codebook, we have demand/calculation tables, we are qualified to do a load calc.

Minimal is interpreted differently for everyone. I wouldn't do it myself, the only reason I'd bump to 250mcm is if the distance was great and I knew they'd be pulling a lot of load, in this instance, this is not the case.

To make a potentially long response much shorter, suffice to say, you don't have a clue.

using your logic since he only needs 100A, then why not use a full rated 100A panel & conductor, not a derated 200A...correct? or a full rated 150A

minimal is pretty easily defined: if it's only 2% of the total installation, and considering your buying a much larger panel and conductor than actually required by the load anyways, then why not 'splurge' to full rate the system since you're wasting $$$ on anyways? waste a bit more...
if $$$ was the concern, go 100A full rated...and since the wire is Al, cost is minimal...

the term 'engineering supervision' has legal meaning...
in PA most juristictions require that a service entrance or residential construction must be sealed and submitted to be code reviewed by the local authority...
if you are following the code, it's fine, if you are using an exception to the code, that requires calculations and derating, then that needs performed by an engineer, at least in these parts...the calculations are submitted for review...
 

ironman2424

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if your going to run cat5 use seperate pipe. dont put it in with the wires to to 100amp service. 1 inch pvc is cheap, put the telephone, cable and/or cat5 in by itself. will likely cause interfearance otherwise. you can run it in the same trench but i wouldnt run it in the same pipe. just added thoughs that might be helpful........
 
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