How should I connect my new Fagor wall oven to the existing wiring?

Question

I just picked up a Fagor wall oven off Craigslist to replace our existing and deteriorating (very old) 240/120V Tappan wall oven. The old home wiring from the wall is a metal encased 3 wire Black, Red, White combo.The new oven is rated 240v (60hz, 3600w.) The problem is the Fagor oven’s 3 wires do not match up - they are Black, White and Green. How do I connect these up?

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The newer oven is from Europe - maybe explaining the white L2?

So I can connect the white (neutral) from the house to the green (ground) from the oven?

Answer 1

This is a great example of color codes not meaning that much in North American wiring.

Ground color codes are very clear -- ground is always green, green/yellow or bare. Other colors not so much though.

The nameplate on the oven is extremely clear: It is made for North America (60Hz rating, highly relevant to the clock). It is made for 208-240V, which means aside from ground, it needs two hots. That white wire is a hot, and should be marked with black tape to indicate it as such. It is not a 120/240V appliance, which means it does not need neutral.

The white wire in your wall is neutral, and is useless for this oven (but useful for most other ovens). Cap it off. I certainly can't tell you to mark it with green tape on both ends and open up your panel and move it from the neutral bar to the ground bar, because remarking wires to be grounds is not allowed unless the wire is #4 or larger.

While it is "technically leeegal" to use a neutral wire as a ground wire on a 120V/240V appliance, it is not for a 240V-only appliance. Therefore I would aim for the best of all worlds, and retrofit a ground wire from the oven location to the panel the oven is powered from. #12 will suffice. Bare wire will suffice, otherwise it must be green or green/yellow. The stuff in the wall isn't MC, it looks to me like flexible metal conduit - and it's possible (easy?) to push/pull additional wires into conduit.

On ovens, "which hot is which" doesn't matter. It's perfectly fine to hook up two hots (black and black-taped-white) to two hots (black and red).

Answer 2

Take a good look at your nameplate. It says it is a 208-240V, 60Hz circuit. So unless the nameplate is incorrect, it doesn't require a neutral. So you need to mark your white wire coming out of your cooktop with tape to indicate it is now being used as a hot conductor. Then you need to mark your white wire coming out of the wall with green tape at that point and also mark it at the panel to indicate it is being used as the ground. Also if you have a separate ground bus in the panel. You need to move it to that bus.

So now we are connecting the black to black, marked white to red and green to white marked with green. Make sure the circuit is connect to a 20A 2 pole breaker in the panel.

I am assuming the feeder conductors are a minimum #12 conductor.

Hope this helps.

Answer 3

Ok, old oven didn't have 'ground protection' and only L1, L2, Neutral, new oven has Ground protection and only L1 and neutral. New oven (if it's really 240V) has to be wired oven -> wall. Black -> Black(L1), White -> Red(L2), ground protection (yellow) -> not connected. The white from the wall (N) has to be capped. BUT, because you don't have a ground protection you'll have to install new ground to the oven. you could connect the white from the wall with the green/yellow (those connectors are both connected to the ground so it'll protect the same way but it's not the right way to do, but this way was allowed up to 1996). It's not regoular that the cable coming from the oven has a white conductor for L2 (white should be used as neutral) so check on the manual if it's a 220V (L-L) or 120V(L-N).

EDIT: I found that before 1996 was standard to wire ground to neutral in appliances wiring. So, if your home is old, just do that way.

this is, more-or-less your same issue: example on other site

Answer 4

These are two different configurations of wiring.

• Old wiring: Most likely 3 Pole/3 Wire, which uses 2 hot 120V legs and 1 neutral leg (Example plug wiring)
• New Wiring: Most likely 2 Pole/3 Wire, which uses 2 hot 120V legs and 1 ground (Example plug wiring)

The wiring on your new unit would actually indicate 1 hot leg (black) and 1 neutral (white) which would be 120V. However, if you are absolutely certain that it wants 220/230V, then we can assume that black is L1 and white is L2, with green being ground. If you have any doubt at all about any of this, please stop and contact a qualified electrician. Saving a few dollars on DIY is not worth risking your life.

To check the wiring from the wall, you should use a multimeter. If you don't have one, you can get a cheap one from your nearest home improvement store. They are well worth having. You will want to configure your multimeter to measure Volts AC (Usually a V with a squiggly line over it). If you are not comfortable with this, please contact a qualified electrician.

Then, after ensuring that no wires are touching, and with the breaker turned on, take the following measurements: Red to Black (should be 210-240V), Red to White (should be 110-130V), and Black to White (should be 110-130V). If these measurements are correct, shut off your breaker and wire the black (wall) to black (oven) and the red (wall) to the white (oven). Unless the manual specifies in the wiring that the green is neutral and not ground, DO NOT wire the white (wall) to the green (oven). This is considered a bootleg ground and is most certainly not safe and against code. Your safest option is to add a ground wire to the run. The other option would be to shut off your main breaker box and rewire the white (wall) from neutral to ground. Then you can use it as ground at your new oven. This is not recommended as this further strays from accepted color conventions, but if you explicitly label the white wire on both ends as ground, I believe it would be an adequate (although not ideal) solution. Finally, if any part of this is unclear or you are uncertain, do not proceed and consult a trained electrician (or at the very least, a very knowledgeable friend).