aluminum wiring

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Rweenzz

Member
I do service work for a group of condo's, and the manager is asking that I write a letter to their insurance company, reassuring them that the existing wiring is safe and up to code. The service conductors ran to the sub-panels in each unit is of Al wire. The only other Al wiring in each unit is to the water heater #10, 240 volt and to the stove #6 240 volt. I'm trying to find the code section that allows the use of Al for services and also the section that allows the service, servicing the stove and water heater to be Al as well. I would appreciate the help... I have looked up all I can trying to find the section but have found nothing that specifies what I am looking for.

thanks for your help.... Rob
 

jumper

Senior Member
No where in the code does it state that you cannot use AL conductors for those applications; therefore, it is allowed as the code is permissive.

One section that would seem to apply would be this:

310.10 Uses Permitted. The conductors described in
310.104 shall be permitted for use in any of the wiring
methods covered in Chapter 3 and as specified in their
respective tables or as permitted elsewhere in this Code.

310.104 is about insulation and not AL or CU conductor material.

Ampacity is 310.15(B)(16) which lists AL and CU.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
Nothing wrong with AL as long as the terminations are done properly.
Proper use of anti-ox. torque.
Most utilities use AL.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
What size water heater? #10 aluminum is only a 20 amp conductor.

I have seen water heaters on #10 AL . I think it was acceptable at the time from what I remember.
Sounds like this place wa built in 60's 70's. or in an area that is several cycles behing the current code.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
As far as I know forever at 60 and 75 C

at 60 deg thats 25
at 75 deg that 30

I don't know what you are speaking of.
Yes the limit was 20 amps for a receptacle many code cycles ago. However from breaker to direct wired equipment the above ampacity was used.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
Correct me if I am wrong,
Water heater 4500 watts
125 % for continous load 5625 watts

Circuit ampacity 5625

#10 wire 6000 watts @ 60deg C
 

iwire

Moderator
Staff member
Location
Massachusetts
at 60 deg thats 25
at 75 deg that 30

I don't know what you are speaking of.
Yes the limit was 20 amps for a receptacle many code cycles ago. However from breaker to direct wired equipment the above ampacity was used.

Strange, my book shows 20, 20 & 25 for 12 AWG aluminum.
 

kwired

Electron manager
Location
NE Nebraska
Strange, my book shows 20, 20 & 25 for 12 AWG aluminum.
You must have an early version and I bet you can find newer versions that have had this mistake corrected. Somewhere they have documentation that tells what mistakes were corrected in which versions.

Should be 15,20,25 for 12AWG AL per 2011



Bingo, that was the question.

And 25,30,35 for 10AWG.

But there is also a ** sending you to 240.4(D) which will tell you this conductor can only be on a 20 amp max overcurrent device. You can still use the 25,30,35 as a base before ampacity adjustments though.

Add:
Sorry 240.4(D) says 10 aluminum can be used on a 25 amp breaker max. That works just fine on your typical 4500 watt water heater.
 
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norcal

Senior Member
Local builder (built a lot of homes) used 10/3 NM AL for the dryers, combined w/ Zinsco/Sylvania panel, but they built em as cheap as they could get away with.
 

kwired

Electron manager
Location
NE Nebraska
Local builder (built a lot of homes) used 10/3 NM AL for the dryers, combined w/ Zinsco/Sylvania panel, but they built em as cheap as they could get away with.

And if they were on 25 amp breakers they were code compliant - unless 30 amps was required, but that would mean over 6kVA units to require over a 25 amp circuit.
 

kwired

Electron manager
Location
NE Nebraska
Zinsco never made a 25 amp breaker though
That I can not verify.

There are many that think there is no 25, 35, 45, 80, 90 or 110 amp breaker for several product lines out there, but I would guess that is wrong in almost all cases, they are all standard sizes. Just because HD or Lowes doesn't carry them doesn't mean they don't make them.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
That I can not verify.

There are many that think there is no 25, 35, 45, 80, 90 or 110 amp breaker for several product lines out there, but I would guess that is wrong in almost all cases, they are all standard sizes. Just because HD or Lowes doesn't carry them doesn't mean they don't make them.

For Zinsco that animal never existed. 25A
 
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