Double Oven replacement – use existing wire?
We are currently replacing a double oven in our home that was originally installed in 1978. It was a 23″ Whirlpool rated at 6.3kW/208V @ 7.3kW/240V. All of our large appliances are wired with Stabiloy SEU XHHW 300V to ground 3 conductor #6 aluminum wiring (two blacks and an uninsulated neutral). It has been running on 30A breaker since it was installed. The new oven is a 24″ Kenmore that is rated at 5.1kW/208V @ 6.8kW/240V. It is requiring a 40A breaker.
My questions are:
1. Is the 6/3 Al wire fine to use? I removed the old oven because I will need to enlarge the hole and build a short base to bring the new unit up a bit. The whip was wire nutted (gray nuts) and I saw no evidence of arcing or anything else going on. I would prefer to run new copper wire, but with the price of copper here it would most likely be prohibitive at this point in time.
2. I know the new unit is asking for a 40A breaker, but the old one pulled more juice than this one and it has been fine with a 30A breaker. I could see going too large and there being problems, but a smaller breaker shouldn’t be a problem unless it’s causing it to trip. This leads back to question #1.
I will not be doing any electrical work myself on the installation, but would like to be informed before it is done.
Thanks for your time.
Replies
6 ga al is OK with a 40a breaker.
OTOH 6.8KW @ 240v is only 28amps so your 30 breaker will work.
Two problems
One is that it is AL
The other is that the new codes requitre an extra wire that you don't have
So long as the unit doesn't require a 4-wire service (and I doubt that a 208/240V unit would) then the existing wire should be fine with a 40A breaker. Be sure to use some anti-oxidant grease on the connections.
Thanks everyone. We had the oven delivered today and it looks like it will only take a 30A breaker according to the installation manual.
Now the lousy part. The cabinet is 24" deep, the oven 23" deep, the whip 1" in diameter coming from the top of the oven behind the panel controls. The outlet box is recessed right in the middle of the cabinet back wall. The old oven was only 21 1/2" deep. Guess we'll find out if it's gonna fit or not.
There's always this answer to tight quarters..........
Hog out the back of the cabinet to make room for the sheathed wires.
But, even with a ninety deg. connector on the box, you might be maxed out for room.
Sometimes, there's enough cable in the right direction to allow moving that box to another location.
The instructions should give you the optimum place-then it's fly by the seat of your pants.....................