Copper or Aluminum feed for range?

WSG

MN elec contractor
Location
Minnesota
Occupation
Electrician & Contracor
I'm wondering why I would not use an aluminum cable for my range feeds!? Can you talk me out of it? I've almost exclusively used a 6/3 NM cable in the past when roughing-in a range feed. Now I'm leaning away from that past practice. Check out my latest costs for 125ft of the cables shown below. Tax not included.
  • $153.48 -- SER 6-6-6-6 AWG Aluminum Round Service Entrance
  • $192.89 -- SER 4-4-4-6 AWG Aluminum Round Service Entrance
  • $618.49 -- NM-B-6/3-CU-WG-1R Copper with Ground
If using the Aluminum SE cable, I would use either a 50A 4-wire receptacle for appliances with a cord or I would use CuAl insulated lugs for hardwired situations.

At these prices, why use a copper feeder for any other residential work I do?
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Aluminum for anything above 30 amps.
I used it for my own oven/ cooktop combo also, and have for 20+ years (when I did that). AC units are aluminum, etc..
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
We always used copper but now the aluminum wire is made from a different alloy and it doesn't have the problems associated with the old aluminum wires. We use aluminum alot for larger cable runs
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
If using the Aluminum SE cable, I would use either a 50A 4-wire receptacle for appliances with a cord
Just make sure you get a receptacle labeled for aluminum and for 75C terminations. The latter lets you use #6 Al on a 50A breaker that is also labeled for 75C terminations. If you are limited to 60C terminations, then you need the #4 Al you mentioned for a 50A breaker.

Cheers, Wayne
 

WSG

MN elec contractor
Location
Minnesota
Occupation
Electrician & Contracor
It's interesting that NM-B is limited to 60C for ampacity while SE cable can be used at 75C ampacities. The SE cable must have a superior conductor insulation and outer jacket system.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
It's interesting that NM-B is limited to 60C for ampacity while SE cable can be used at 75C ampacities. The SE cable must have a superior conductor insulation and outer jacket system.
I doubt that there is a technical justification for the difference in treatment in the NEC.

Cheers, Wayne
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
It's interesting that NM-B is limited to 60C for ampacity while SE cable can be used at 75C ampacities. The SE cable must have a superior conductor insulation and outer jacket system.
Se cable went from 60C to 75C back to 60C and now it is 75C in most cases.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
We always used copper but now the aluminum wire is made from a different alloy and it doesn't have the problems associated with the old aluminum wires. We use aluminum alot for larger cable runs
Just be sure that if you install compression lugs on aluminum conductors they are rated for use on aluminum. A guy I know learned this lesson the hard way a few weeks ago. The project experienced multiple thermal events at many connection points, and a lot of wiring and equipment had to be replaced.
 

WSG

MN elec contractor
Location
Minnesota
Occupation
Electrician & Contracor
I use insulated lugs from Ilsco. Other mfgrs make similar products. These connections are dual rated (CuAL) and nice to work with.

In the case of a hardwired range I would use three or four of these lugs. Cost is around $20 each for a 2-port, 14-4AWG. That is an offset to the lower cost of Aluminum cables.
Screenshot_20210922-112750.png
 

WSG

MN elec contractor
Location
Minnesota
Occupation
Electrician & Contracor
I agree AL is great. IVe pretty much always used 6 SER for range feeds my entire 20 year career. Large
NM is the worst: expensive, low termperature rating/ampacity, dry only, no free milkshake with purchase......
I'm on the AL train, bought a ticket!
 
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