On Saturday, March 18, 2017 at 4:55:38 PM UTC-4, wrote:
On Sat, 18 Mar 2017 12:32:47 -0700 (PDT), John G
wrote:


I have had aluminum wire feeding my free-standing range for over 25 years with no problems, but now I am concerned that it still could be a problem if it is connected to a copper screw at the breaker box or the outlet behind the stove.

Could this cause a fire or should I have the wire replaced with copper wire?

The wire has no visible markings of what size it is but I would guess #6 wire.

The breaker box and stove outlet have been there since day one. I am not an electrician and could use an opinion.


Thank you Tina

(My concern came from some new reports on TV about home fires.)

If the terminals on the circuit breaker and the stove are rated for aluminum wire you should be okay as long as all connections are tight. Loose connections cause arcing which generates heat and sparks.

The circuit breaker should have a label on it with CUAL or ALCU or something similar. The stove wiring diagram or a label at the power connection should indicate the same thing.

If the stove is not rated for aluminum wire, you can install a surface mount range receptacle on the wire, and mount it on the wall very low. Then connect a range cord to the stove and plug that into the range receptacle. Make sure that the range receptacle is rated for aluminum wire (They usually are). Range receptacles and cords come in 3 wire and 4 wire versions. Four wire is preferred, but if you only have a three wire cable coming out of the wall, go with a 3 wire range receptacle and cord.

The circuit breaker can be replaced with one rated for copper and aluminum.

John Grabowski
https://www.MrElectrician.TV
The range WILL already have an outlet for the stove to plug into.
AFAIK Aluminum wiring was NEVER used "direct connected" to a stove -
at least not within code.

John

Many electric stoves were built, tested and listed by a recognized electrical testing laboratory, sold, and installed with connection blocks which were listed for both copper and aluminum conductors. The reason that the lugs are seldom used for connections of cables is the requirements for ease of servicing and cleaning in many residential codes which in turn dictate the use of cord and plug connections for kitchen ranges. In those areas where such residential codes are not adopted it is very common to see the cable connected directly to the range. With built in counter cook tops and ovens it is rare to see cord and plug connections used because of the increased cost of the additional parts and the additional labor that would be required for installation. As long as the connections are listed and or labeled for both Copper & Aluminum conductors there is no issue.

One of the factors which led to a lot of direct connection of Aluminum conductors to ranges was an exception in prior editions of the National Electric Code (NEC) in the USA which permitted the range's non current carrying conductive parts; such as the frame and metal case; to be bonded to the neutral of the supply circuit in lieu of requiring a separate equipment grounding conductor provided that the circuit originated in the Service Equipment. Since the neutral would only carry a rather small current during normal operation it was thought that the voltage drop would be low enough to avoid any hazardous difference of potential between the range and adjacent grounded surfaces such as refrigerators, metal sinks, other electrical appliances, and so forth. This exception may have originated during world war two as a materials conservation measure. Experience with it showed that although problems were quite rare any high resistance connection or open in the neutral to the Ranges and Clothes Driers installed under this exception created an extremely dangerous condition. As a result the exception now applies only to extensions of the original circuits and the installation of replacement appliances. Thousands of these installations will be around for decades.

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Tom Horne