nate379
Banned
Can someone explain to me how 4 gauge aluminum wiring can power a 125amp panel?
4AWG Al wiring
- Thread starter nate379
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Nostraquedeo
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What size is the breaker feeding that panel? or what is the main breaker in the panel?
twostory
Well-known member
Short answer: "It can not"
#4 AL wire is rated 55amp to 75 amp, depending on the temperature and the type of insulation.
Here is a chart:
http://www.allenelectric.com/referencedata/ampacity.htm
#4 AL wire is rated 55amp to 75 amp, depending on the temperature and the type of insulation.
Here is a chart:
http://www.allenelectric.com/referencedata/ampacity.htm
Nostraquedeo
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twostory
Well-known member
According to that chart (the cable manufacturer), you can run 110 amp thru that cable, if the cable is hanging in the air.
If it is in a race way, you only get 75 amp.
If it is buried in the ground (not on the chart) you may have a reduced current capacity.
The very cold soil in Alaska will help with the current capacity, since this cools the wire down. The wire has internal resistance, which will noticeably heat the wire when you run 100 amps thru it.
Aluminum XHHW has a 75deg ampacity of 65 amps. 75 amps is from the 90deg column which can only be used for derating purposes. You cannot select your overcurrent protection based on ampacity from the 90deg column.
Once again, #4 AL needs to be protected by a 60 amp breaker in 99% of all cases.
It's protected by a 100amp breaker. Wired by an electrician so it's not anything I did.
The Wire runs in the attic I think. Meter box is outside the house on the bedroom wall and the panel is in the garage which is the opposite side of the house.
I would not think something that obvious could be done if it wasn't ok.
The Wire runs in the attic I think. Meter box is outside the house on the bedroom wall and the panel is in the garage which is the opposite side of the house.
I would not think something that obvious could be done if it wasn't ok.
obviously that electrician didnt know what he was doing. I would replace that 100a breaker with a 60 asap, especially if its running through the house.
Gary S
Well-known member
#4 aluminum with a 100amp breaker ain't going to happen on my property no matter who put it together. My garage has #2 copper with a 100amp breaker.
hidollartoys
Well-known member
I have read and reread this post and it seems that the wire in question is actually a "feeder" as defined by the 2005 NEC code. Per Table 310.15(B)(6) pg 70-141 the wire size for 100 amp feeder is #2 al or #4 cu.
That is Incorrect. 310.15 B 6 is for the service feeders that supply main power to a dwelling. A set of conductors supplying a sub panel cannot use the reduced sizes offered by that table.
Aceman
Well-known member
He's right mrb. If that is the only lighting/appliance panel in the home, that feeder qualifies.
I misinterpreted his post. I thought we were talking about a panel for the garage which was a sub panel coming off the main on the side of the house.
So this panel supplied with the #4 carries the entire load of the house? In that case, the #4 would need to be a #2 AL, but only if that panel its supplying carries the entire load of the house. If there is another breaker at the main which supplies anything on the house or attached garage then 310.15B6 is out for sizing that feeder.
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Its #4 al not CU
right, so per 310.15(B)(6) it would need to be #2 AL. Thats 2005. Is it conductors in conduit or is it cable? If its cable i think there is additional derating for SER if under 2008
Schrodingers Cat
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this is confusing:
is this the main feed for the house/garage?
or just a 100A feed from the service entrance to the garage alone?
is the SE overhead or underground?
is the wire from the meter box/100A CB to the garage panel in conduit?
my understanding:
SE into meter box (OH or UG)
meter box has a 100A Main CB
then the #4 Al goes from the meter pnl/100A CB to the main (and only) house/garage dist panel 125A (located in garage)
is this correct?
is this the main feed for the house/garage?
or just a 100A feed from the service entrance to the garage alone?
is the SE overhead or underground?
is the wire from the meter box/100A CB to the garage panel in conduit?
my understanding:
SE into meter box (OH or UG)
meter box has a 100A Main CB
then the #4 Al goes from the meter pnl/100A CB to the main (and only) house/garage dist panel 125A (located in garage)
is this correct?
hidollartoys
Well-known member
Yes and garage is attached to dweling. Service disconnect and main panel are 40 ft apart. Wire is routed through attic.
Yes that's correct. Juice runs from the power company underground to the meter box on the side of the house and the main breaker, (which is 100amp) is there as well.
From the meter the wire in question (#4 AL) is used to get to the one and only breaker panel which is in the garage, about 40 ft from the meter.
It's not in conduit, just sheathed the same way Romex would be. 2 hots, 1 neutral and a ground wire. The pic of the grey wire shows what it looks like. (That wire is a "spare" #6 for the electric oven which I don't have)
From the meter the wire in question (#4 AL) is used to get to the one and only breaker panel which is in the garage, about 40 ft from the meter.
It's not in conduit, just sheathed the same way Romex would be. 2 hots, 1 neutral and a ground wire. The pic of the grey wire shows what it looks like. (That wire is a "spare" #6 for the electric oven which I don't have)
Attachments
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I sent an email to the builder's agent with the info you posted. Do you have a copy of the page with the exact info I need? I searched on the web and can't see to find it. I'd rather not spend $75-80 for the code book just for this one thing.
"...The last concern is the feed wire from the meter panel outside the house
to the main panel. I pulled the breaker panel cover off in the garage to prep for painting the walls and I noticed that the feeder into the panel is #4 XHHW-2 Aluminum wire. It seemed small for 100 amp service, so I checked into it. Per the NEC (National Electrical Code) 2005 codebook, Table 310.15(B)(6) (pages 70-141), the wire size for 100 amp feeder should be #2 Aluminum OR #4 Copper. The #4 Aluminum wire is only rated for 65 amps. I'd like to know why #4 was used and how this can be legal since #2 is required by the NEC."
"...The last concern is the feed wire from the meter panel outside the house
to the main panel. I pulled the breaker panel cover off in the garage to prep for painting the walls and I noticed that the feeder into the panel is #4 XHHW-2 Aluminum wire. It seemed small for 100 amp service, so I checked into it. Per the NEC (National Electrical Code) 2005 codebook, Table 310.15(B)(6) (pages 70-141), the wire size for 100 amp feeder should be #2 Aluminum OR #4 Copper. The #4 Aluminum wire is only rated for 65 amps. I'd like to know why #4 was used and how this can be legal since #2 is required by the NEC."
i have the online nec, cant print or copy. Maybe someone else has the book and can scan the page for you.
that panel is a mess. Whats the jumper thing between the two neutral bars above the top two breakers? is it bare? Doesnt look factory. Wheres the factory jumper? I dont like how this passes across the two hot busses.
that panel is a mess. Whats the jumper thing between the two neutral bars above the top two breakers? is it bare? Doesnt look factory. Wheres the factory jumper? I dont like how this passes across the two hot busses.
Why are the grounds from the romex all black looking? When was this house built?
see this http://www.chinesedrywall.com/
and the ground bus picture at the bottom of this page http://www.chinesedrywall.com/gallery.html
see this http://www.chinesedrywall.com/
and the ground bus picture at the bottom of this page http://www.chinesedrywall.com/gallery.html
Panel isn't the neatest, but I have seen worse with "pro" jobs. As with anything, some people take more pride in their work than others.
The jumper is factory I think, I'm not sure. It's a Siemens panel. It has insulation on it, just hard to tell in the pic. It runs in front of the hots, about 3/4" away from them.
Bare copper is black a little from dust (cover has been off for a while) and also when I did the epoxy on my floor the acid didn't like the copper too much. The water pipes in the garage are like that as well.
Mistake I made not covering everything up, but I didn't know it would do that until after the fact, so not much I can do now.
It's not as bad as it looks in the photo, just the lighting makes it look like that.
No China drywall in the house, it's all made in the USA stuff.
The jumper is factory I think, I'm not sure. It's a Siemens panel. It has insulation on it, just hard to tell in the pic. It runs in front of the hots, about 3/4" away from them.
Bare copper is black a little from dust (cover has been off for a while) and also when I did the epoxy on my floor the acid didn't like the copper too much. The water pipes in the garage are like that as well.
Mistake I made not covering everything up, but I didn't know it would do that until after the fact, so not much I can do now.
It's not as bad as it looks in the photo, just the lighting makes it look like that.
No China drywall in the house, it's all made in the USA stuff.
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ah ok. good you didnt end up with that drywall. I would clean the ends of and reterminate all the copper wires in that panel. An hour of work that could save a bigger headache later. Were the breakers installed when doing the floor which caused the corrosion? If so, I would replace any that carry a high load.
hidollartoys
Well-known member
Nate, maybe a call to your local codes inspection office is in order. If the house was given a certificate of occupancy then it might be something that needs to be addressed at the codes dept. management level. You might want to contact your insurance co to assist in your efforts. I believe the way it is now is wrong and should require a change. Just my two cents.
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hidollartoys
Well-known member
Nate in that last picture it appears to be a #6 AWG that you have shown. Is it feeding the range or is this the wire in question?
That #6 wire would feed the range if it the range were electric (both the range and dryer are setup for electric and gas).
I took a pic of it because the #4 feeder wire is the same type of wire.
I sent the builder's rep an email and I'll see how that goes. I have a 2 year "bumper to bumper" warranty plus a 10 year structural and so far they have been pretty good to deal with thankfully.
I took a pic of it because the #4 feeder wire is the same type of wire.
I sent the builder's rep an email and I'll see how that goes. I have a 2 year "bumper to bumper" warranty plus a 10 year structural and so far they have been pretty good to deal with thankfully.
Nate, Maybe it is just the picture quality, but it sure looks like I see some copper strands coming out from the bottom of the main lugs in the second photo. I also see the AL on the neutral conductor. Is it possible that it is just the neutral that is AL and the other two are copper... or am I just seeing anti-oxidant paste?
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Electrician is supposed to come by today to take a look.
I told him 125 amp breaker, #4 Aluminum and right away he said, HUH??
He wanted to know the timeframe it was wired so he can figure out who did the work. I was digging through paperwork a couple days ago and found that there was actually an electrical inspection done.... or... well signed off at least.
Futher proves my point that permits/inspections are a complete waste!
I told him 125 amp breaker, #4 Aluminum and right away he said, HUH??
He wanted to know the timeframe it was wired so he can figure out who did the work. I was digging through paperwork a couple days ago and found that there was actually an electrical inspection done.... or... well signed off at least.
Futher proves my point that permits/inspections are a complete waste!
Aceman
Well-known member
Not all inspectors are clueless. You simply had a complete failure of the system.
I'd probably look for contractor/inspector info on your permit label and bring it up to the local building dept. That's BS they wired your home that way and got away with it. You shouldn't be the one having to pay to fix it. On the bright side, at least it looks like you found an electrician who seems to know what he's doing.
glad to hear its getting straightened out. I dont know I would completely blame the inspector (although they should have caught this), as the electricians are the ones who are supposed to make sure they do their work to code. The inspectors cannot possibly catch every little thing, and they usually just have a laundry list of things they check for.
Aceman
Well-known member
sberry
Banned
I don't hang out a sign but on occasion get a call from friends, I can tell right away when the local "handyman" did the work to a place. Cut every ground wire off he come across. An Uncle called me a while back with water heater problem, I don't remember what was exact issue but the joker that replaced it snipped the ground wire off both ends of the cable. Went to another buds garage, same deal on every outlet and wires are now to short to re-use, gfci time. Did this to hundreds of things he worked on, just couldn't grasp the concept I guess and knew more than most people do about it, enough he never ask anyone WTF.
sberry
Banned
I am not a neat freak, my own panels got some strangled wire in them but I don't put both wires under the same screw thats for sure and make sure stuff is grounded and the bonds are in place.