In article xFC1h.232445$R63.215780@pd7urf1no, Tony Hwang wrote:
BobH wrote:
I am remodeling my kitchen and have a new wall oven and a new cooktop.
In the wall, there are separate junction boxes containing 240-volt
aluminum wires for the oven and the cooktop. Each junction box has four
aluminum wires -- two black, one black with a barely recognizable white
strip and a bare wire. The bare wire is connected to a lug screwed to
the metal box.

My question is how to wire the two appliances. The oven comes with a
four-wire copper cable. I suppose the bare wire from the oven should go
to the bare ground wire, white should go to the white-striped neutral
wire and black and red should go to the two black wires. Are the two
black wires in the wall interchangeable? If not, how do I know which
one goes to the red from the oven? Why are there four wires in the
first place?

The cooktop, on the other hand, has only three wires -- red, black and
bare copper. Why no white? How should I match up the three cooktop
wires with the four wires in the wall.

I realize I need to use antioxidant in the wire nuts when connecting
aluminum to copper. Any other precautions needed?

--Bob

Hi,
Do you have multi meter? Also wire nut should be Al-Cu compatible.
Oven takes 240V and it uses 120V off it. Two black is hot and one white
strip ought to be neutral.

Maybe... given his description, it's hard to tell exactly what he has. No way
should there be three black wires and one bare one in a junction box.

Top is using only 120V so you'll have to
connect it to one leg of 240V between a black and neutral.

WRONG WRONG WRONG WRONG.

The cooktop is using 240V -- as *clearly* shown by the use of red and black
lead wires with no white. The red and black lead wires must be connected to
the two legs of the 240V supply, and the bare lead to ground.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.