Correct way to install an oven

Hi my oven came with a metallic cable sheath that contains 4 wires, black, red, and white and green.

To be fully code compliant:

1. Do I need a range style plug or can I just connect the wires with properly sized wire nuts?
2. I will be installing a new electrical box. If I need a plug/socket it's obvious, but if wire nuts are allowed what is the best way to close the box so the sheath goes into the box providing protection to the wires?
3. This oven does not need neutral to work. In fact, ground and neutral are "bound" together (will send a picture). As I need to run a new cable from the panel, am I correct when I say that that a 3 wire cable of the correct gauge is enough?

 

You wrote: That would indicate you need a neutral. So further explain: Yes a picture would help. http://www.doityourself.com/forum/li...-pictures.html

No, would be my answer based on the fact you have a four wire whip. Explain more fully your statement about neutral being bonded to ground and we will go from there. It sounds like neutral and ground need to be separated.

 

As soon as I get home I will take a picture, I am sure that will explain everything.

Let's assume we figure out if I need 3 or 4 conductors; what about the best way to close the box and the sheath? I tried to look for pictures all across the web but could not find an example

 

You would use a blank cover plate with knockout and an MC connector.

 

The white and green are connected for an older 3 wire installation. If you have 4 conductors you would split the white and green or bare into their respective colors and splice.

While Ray shows an 8B cover I would use a 4" square deep box and cover. I also don't like using a center knockout in the cover.

 

Thanks, that blank cover plate is exactly what I wanted.

 

pcboss, why do you not like the center knockout? Yes the square box seems a good idea, I will have a look at the store, but what other method do you suggest to let the wires in?

 

I now include the instructions and some pictures.

These are the instructions found on the label; I am not a Native English speaker, and I find this label pretty hard to understand. The appliance is a Kenmore "Made in Canada" probably they use a different slang over there.

************
If your appliance is equipped with a white neutral connector:
This appliance is manufactured with a white neutral power supply and a frame connected copper wire. The frame is grounded by connection of grounding lead to neutral lead at the termination of the conduit, if used in a new branch circuit installation (1996 NEC), mobile home, recreational vehicles, or where local code do not permit grounding trough the neutral (white) wire, disconnect the white and green lead from each other and use ground lead to ground unit in accordance with local codes, connect neutral lead to branch circuit-neutral conductor in usual manner see Figure 4. If your appliance is to be connected to a 3 wire grounded junction box, where local code permit connecting the appliance-grounding conductor to the neutral (white) see Figure 2.

If your appliace is not equipped with a white neutral conductor:
Connect only to a 3-wire, 120/240V power supply,; the neutral conductor is not required for the operation of the appliance. The potential at the power supply electrical connections shall be 150V to ground or less. See figure 1 or 3.
************

Figures (higher resolution photo):


Picture of the wires. Note that the green and white are "taped" together (higher resolution photo):



My understanding at this point is that I need to run a 4-wire cable.

 

Figure 4 of your picture is correct for a four wire circuit.

Note while I showed a straight MC connector a 90° connector would be better. Trying to get the MC to conform to the radius of the MC is difficult I think PCBoss was suggesting a surface mount box with the MC out the side. A 4" box as he suggested gives you more room.


What is the amp rating of the oven? Do you want to use cable or conduit?

 

Correct Ray. I just come out of the side knockout in the box. That way I don't have to work behind the box cover. It also make it easier to dress the wires before putting the cover on.

 

Amp rating of the oven. Good question; I was getting there. I read all the manuals that came with the oven and also looked for a label on it without finding it. Suggestions where to look for? The only info I have at this point are from the website:

Kenmore Elite 30in double wall oven
Lower Oven Broiler Element Wattage: 4000
Lower Oven Convection Wattage: 2500
Upper/Single Broiler Element Wattage: 4000
Upper/Single Convection Wattage: 2500 watts


The wires coming out of the oven are #10 and the insulation is rated for high temperature.

As it is a double oven with convection on both units etc, I think I should be abundant with the wiring and maybe assume 50A. What do you suggest?

 

For the box: I thought I would mount the box flush to the drywall screwed to a beam. The wiring will come up from the lower floor through a hole. That lateral 90 degrees connector would make things complicated... unless there is something, a mounting technique that I'm not understanding at this point!

Thank you

 

If I am understanding you intend to run the whip into the basement or instead of beam did you really mean stud?. Usually the surface mounted box would be in the cabinet below the oven. A picture of the cabinet the oven goes in might help us help you.

 

Ray: sorry, but as I am not a "native" English speaker and I have just bought my first house, I am building by technical vocabulary "as we speak" I also realize that I must have made a lot of confusion with terms. And yes, I meant "stud".

My kitchen is on the upper floor. The floor below has a so called "acoustic ceiling" with "panels" or "tiles" that I can easily remove and that space is already used to run wiring. In fact I can also access gas and water pipes. That is where I wanted to run the new wiring (oh, I'd like your opinion there). Tonight when I go back home I can take a picture.

About the kitchen. We plan to remodel later this year or next year. For this reason, for now I have bought just a cabinet that I was going to put against a wall that is not used for anything else now, and where I need to bring the new wiring to. It's a simple "IKEA" cabinet that is 30" wide 88" tall, has a drawer below the "oven" space and a shelf above. Almost identical to this one:



So my idea was to make a hole in the cabinet for the oven wires to exit the cabinet and having a box in the wall. Any idea or comment here is appreciated!

 

Easiest in my opinion would be to surface mount a 4X4 box above the oven in the space where the doors are. You'd just drill a hole through the wall into the cabinet for the power cable to the box and surface mount the box. The whip, metal cable on the oven, would go up into the top cabinet and into the surface mounted box.

Assuming the oven is a single oven and won't fill the space below and you plan to cover the space below the oven with cabinet doors the Jbox could go below the oven.

I have not suggested putting the Jbox behind the oven because there may not be enough space and wiring is very tricky since you must some how hold the oven out while working to wire behind it.

P.S. Your English is too good for me to remember you aren't American.

 

OK good idea but which type of cable should I use to run the wiring from the main panel to the cabinet? SER? NM? What gauge? Conduit or not?

 

NM-b probably 8-3 on a 40 amp breaker but you have not given me the amps of the oven so it may be different. If you use NM-b you would only use conduit for protection where it is exposed to damage.

Note I edited my post above so you might want to re-read it.

 

Oh you must have missed message #11 in this thread, where I explain what type of oven it is, and where I wonder why they do not simply state how many amps it requires. Can you have a look there?

 

I missed that post, my bad. There should be a metal name plate in or on the oven that gives the full load amps. Based on what you posted though it would be 6-3 on a 60 amp breaker but that would be unusual for an oven. If you can't find the name plate and FL amps wait for the pros to comment.

It does have just the one whip doesn't it?

 

OK I will try again to find the plate. There is only one "whip", correct.

 

OK I have checked all the oven inside and outside and I have only found this label (full resolution):



Bottom line it says 9.2kW that at 240V it's about 38A accoding to ohm's law (an oven should be a mostly resistive load).

Suggestions? Should I get a 50A breaker and wiring??

 

Yes, 6-3 NM-b on a 50 amp breaker.

 

6 gauge? Ouch I was hoping I could get away with a #8 OK, I will see if I can find a good price

 

You would have to use a 40 a breaker on # 8 and while the oven might never draw full amps it is best to go to the larger feed. For the record most ovens are on 40a circuits. You might want to look at the owners manual to see what is recommended. You could use #4 aluminum SER or individual #4 aluminum wires in conduit.

 

No it's OK I do not want to be cheap on wiring. Now that I think I have all my answers I will check with the inspector, I will let you know how it works out.

bye! Thanks!!!

 

It's too bad more people don't have your attitude.

 

If you check the installation manual you will see where to mount the junction box.

Be sure to use a flex connector on the end of the whip.

 

So I went to Home Depot (for not knowing anything better) and now I am pretty confused. Apparently at least in this store they only sell by the foot, and not a whole spool.

In any case a question: why "NM" cable and not THHN like? I mean the "stranded" version. My understanding is that the stranded one has better electrical properties, it is rated higher amps for the same gauge (but may cost more) and is much more flexible and easy to work with.

Isn't it better?

 

THHN must be installed in conduit.

Electrical properties are the same. Slightly higher rating is based on insulation. What would be easiest for you is 6-3 NM-b. Were you told different by and HD associate? If so what did they say?

 

OK so there isn't a stranded type of wire/cable that does not need the conduit?

No, I do not generally talk to associates, nothing wrong with them, it's only that my vocabulary is limited in this matters and my pronunciation is not perfect so it's always a problem to communicate effectively. The reason I was attracted by the stranded wire is that I worked under an electrician a couple of summers back in Europe when I was a teenager, and we would always remove the old solid wire and replace it with stranded. I do not even think solid wire is sold anymore in my country but this is besides the point, I do not even know the reason.

Thanks

 

#6 NM-b if I recall correctly does have stranded conductors.

 

I'm pretty sure that all insulated wire #6 and larger is stranded. Stranded wire is easier than solid to pull through conduit and generally easier to stuff into boxes but it has no electrical advantages over solid wire, at least not in any normal less-than-600 volts application.