[BobH]

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

[Tony Hwang]

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

[Tony Hwang]

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,
Can you tell the power requirement for the cook top? From the sticker or
manual? Also do you have a multi-meter of some sort?

[RBM]

Tony has the wall oven wiring correct, but the cooktop is 240 volt not 120
volt. Connect the red and black from the unit to the two black feed wires,
and connect the bare wires together and cap the "black with white stripe"


"BobH" wrote in message
oups.com...
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

[RBM]

Some appliances don't use a neutral



"RBM" rbm2(remove wrote in message
...
Tony has the wall oven wiring correct, but the cooktop is 240 volt not 120
volt. Connect the red and black from the unit to the two black feed wires,
and connect the bare wires together and cap the "black with white stripe"


"BobH" wrote in message
oups.com...
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

[Doug Miller]

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.

[Doug Miller]

In article , "RBM" rbm2(remove wrote:
Tony has the wall oven wiring correct, but the cooktop is 240 volt not 120
volt. Connect the red and black from the unit to the two black feed wires,
and connect the bare wires together and cap the "black with white stripe"

The black with white stripe is probably the neutral -- although I sure
wouldn't assume that, without verifying it with a meter -- in which case it
should be connected to the white lead for the oven, not capped.

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

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

[Doug Miller]

In article , "RBM" rbm2(remove wrote:
Some appliances don't use a neutral

True -- the OP's cooktop appears to be one of them -- but the electric oven
*does* use a neutral. The heating elements are 240V, but the control circuits
(clock, timer, etc) typically run off 120V.

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

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

[BobH]

Thanks for the answers, but I'm not quite clear on some details. I
probably should have posted the oven and cooktop questions separately.
Let me try this again.

First, three clarifications:

A. In the cooktop junction box, one of the wires has red markings on
it, so there I can distinguish between red and black. In the oven
junction box, the two blacks look identical.

B. The cooktop clearly takes 240 volts. It is marked 240/120V.

C. I don't have a multimeter.


Questions:

OVEN

1. Is there any difference between the two black leads in the oven box?
Does it matter which one goes to the black oven wire and which goes to
the red oven wire?

COOKTOP

2. Does everyone agree I should just put a wire nut on the white-stripe
wire and not connect it to anything from the cooktop?

GROUNDS

3. In both junction boxes, the stranded aluminum ground is attached to
a lug screwed to the metal box. The oven ground wire is relatively thin
copper, and the cooktop ground is relatively thick copper. What is the
best way connect them to the box ground wire? Should I use Al/Cu wire
nuts on the part of the aluminum that extends past the lug?

MULTIMETER

4. If I go buy a multimeter, is it going to be obvious which wire is
neutral? How will I know?

CONNECTORS

5. I have seen expensive Al/Cu nuts from the Ideal company (about $5
for only two nuts). I think they have antioxidant inside. They look a
little small for my wire, though.

I also have some larger wire nuts and a tube of antioxidant. As I
understand it, the preferred practice when using wire nuts is to tape
them after twisting the wires together and embedding antioxidant in the
nut.

Another recommendation I have seen is to buy a special
aluminum-to-copper "bug" that has separate screws or clamps for the two
wires, and to tape it up after connecting the wires.

The old oven and cooktop had wire nuts with antioxidant in them. Which
is the preferred method?

--Bob

[Bud--]

BobH wrote:

Thanks for the answers, but I'm not quite clear on some details. I
probably should have posted the oven and cooktop questions separately.
Let me try this again.

First, three clarifications:

A. In the cooktop junction box, one of the wires has red markings on
it, so there I can distinguish between red and black. In the oven
junction box, the two blacks look identical.

B. The cooktop clearly takes 240 volts. It is marked 240/120V.

C. I don't have a multimeter.


Questions:

OVEN

1. Is there any difference between the two black leads in the oven box?
Does it matter which one goes to the black oven wire and which goes to
the red oven wire?

No difference/doesn't matter.

COOKTOP

2. Does everyone agree I should just put a wire nut on the white-stripe
wire and not connect it to anything from the cooktop?

Assuming it is the likely neutral I agree.
If they are on the same circuit (same fuse/breaker) IIRC the max size is
50A.

GROUNDS

3. In both junction boxes, the stranded aluminum ground is attached to
a lug screwed to the metal box. The oven ground wire is relatively thin
copper, and the cooktop ground is relatively thick copper. What is the
best way connect them to the box ground wire? Should I use Al/Cu wire
nuts on the part of the aluminum that extends past the lug?

Reasonable. If the wiring to the oven/cooktop is in flexible metal
conduit (not flexible cord) that is part of the ground.

MULTIMETER

4. If I go buy a multimeter, is it going to be obvious which wire is
neutral? How will I know?

120V to each hot, 0V to ground

CONNECTORS

5. I have seen expensive Al/Cu nuts from the Ideal company (about $5
for only two nuts). I think they have antioxidant inside. They look a
little small for my wire, though.

I also have some larger wire nuts and a tube of antioxidant. As I
understand it, the preferred practice when using wire nuts is to tape
them after twisting the wires together and embedding antioxidant in the
nut.

Another recommendation I have seen is to buy a special
aluminum-to-copper "bug" that has separate screws or clamps for the two
wires, and to tape it up after connecting the wires.

There is information on making aluminum wire connections at
http://www.inspect-ny.com/aluminum/alreduce.htm
which is based extensive research, primarily for the Consumer Product
Safety Commission. It does not like the Ideal wire nuts, prefering 3M
wire nuts and antioxide paste.

Someone discovered a more recent product
http://www.alumiconn.com/details.html
but the max wire size is only #10

---
bud--

[BobH]

Thanks for all the answers. One more thing:

What do you think about using a split bolt connector rated for aluminum
and copper. Apparently the wire nuts are too small for these wires,
which I think are 6-gauge stranded aluminum on the 50-amp oven circuit
and 8-gauge stranded aluminum on the 40-amp cooktop circuit.

[Bud--]

BobH wrote:
Thanks for all the answers. One more thing:

What do you think about using a split bolt connector rated for aluminum
and copper. Apparently the wire nuts are too small for these wires,
which I think are 6-gauge stranded aluminum on the 50-amp oven circuit
and 8-gauge stranded aluminum on the 40-amp cooktop circuit.

Split bolts are good but kind of a pain to insulate (plstic tape).

--
bud--

[BobH]

So far, I haven't found any connector made for No. 6 aluminum and No.
16 copper. A split bolt I've seen is for 6 through 10, and a Polaris
I've seen is for 4 through 14. An installer says he uses a wire nut,
which an inspector and some electric supply guys think is a bad idea.
What would you do?

[Tekkie®]

BobH posted for all of us...

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


Asked and answered MANY times! Sorry, you lose, buh bye, bring in the next
player Johnny.
--
Tekkie Don't bother to thank me, I do this as a public service.

[Joe]

replying to BobH, Joe wrote:
You've got it reversed. Cooktops take more juice than ovens. Also you HAVE
to use polaris connectors or something similar to connect different metals, so
no wire nuts. You need to trace the wires and make sure you have the two hots
@ 120V each connected to the red and black from the applicance. Ground to
ground and common to common. If no common on the appliance then the common
isn't used and is not connected to the bus bar, so only the ground is used.

--
for full context, visit https://www.homeownershub.com/mainte...es-161414-.htm

[[email protected]]

On Sun, 06 May 2018 03:44:07 GMT, Joe
m wrote:

replying to BobH, Joe wrote:
You've got it reversed. Cooktops take more juice than ovens. Also you HAVE
to use polaris connectors or something similar to connect different metals, so
no wire nuts. You need to trace the wires and make sure you have the two hots
@ 120V each connected to the red and black from the applicance. Ground to
ground and common to common. If no common on the appliance then the common
isn't used and is not connected to the bus bar, so only the ground is used.

The easiest way to do this is use a receptacle and a plug. Virtually
all of the 30a and up receptacles are CU/AL rated.
I used a regular old 10-30 (30a dryer plug) on mine. (30a circuit, no
neutral). That also provides the disconnect.