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Bob Childress
08-09-2006, 9:59 AM
Okay, here's the problem. I'm remodeling the kitchen and changing from an electric cooktop to gas. The gas cooktop need a 110V outlet for the nurner starters but I now have only a (unused) 220V junction box under the cabinet.

Is it possible to convert this no-longer-needed 220 to 110 somehow. :confused: By using one hot wire plus the neutral? I guess I just hate to tear up the wall to run off another 110 box if I don't have to.:(

What say you?

Larry James
08-09-2006, 10:35 AM
Bob,

Yes. Turn 240 volt breaker OFF. Replace the 240 volt breaker with a 120 volt breaker. Use the black and white wires, if available. With the breaker OFF, wire the black wire to the 120 volt breaker and the white and ground to the neutral bar. Fold the unused wire back into the box on both ends - tape the wire ends. Be sure the breaker is OFF before wiring at the appliance end.

Larry

Kent Fitzgerald
08-09-2006, 10:39 AM
Bob, it may be possible, but there are some considerations above and beyond what Larry outlined. Does the existing circuit have three or four conductors? What breaker size and wire gauge? Copper or aluminum?

The current draw for the gas stove should be very minimal, so it might be easisest to tap off an existing, nearby 120V circuit.

Don Baer
08-09-2006, 10:39 AM
Bob,
The anwer is it depends. If there is a neutral in the box for the 220 it would be simply a matter of taking the wires in the breaker box that feed the circuit from the 2 pole breaker (probubly a 30 or 40 amp breaker) and moving 1 of then to a seperate 20 amp breaker. Then use that 1 hot along with the neutral and hooking it up to the new duplex plug. The wire is going to be a little big since most stoves I've seen are a #8 wire which will be a little fat for at 110 plug circuit but it would work and be kosher. If ther is no neutral then your out of luck. There usualy is a neutral since oven lights are 110 volt.

Bob Childress
08-09-2006, 10:56 AM
Thanks for the replies. I'll clarify a bit if it helps any. The metal junction box in the cabinet (to which the cooktop was hard wired) contains two red, one white, and one ground wire (2 hot, 1 neutral, I assume). The ovens are wall units on a separate circuit, but the cooktop had a "burner on" light which must have been 110V.

You're right, the wires are heavy (8 gauge I would guess). They are copper. The breaker is 30 amp.

Larry James
08-09-2006, 11:31 AM
Bob,

Agree with previous posts, but important that you - DO NOT USE EXISTING BREAKER - single pole 15 amp should be ok, but 20 amp is likely code for kitchen. The larger wire size is not a problem, unless it prevents making good connections.

If you are not comfortable with doing wiring get some help.

Larry

Cliff Rohrabacher
08-09-2006, 11:38 AM
Tie a tight knot in the wire.
That will choke down on the electrons getting through.

Bob Childress
08-09-2006, 12:11 PM
Thank you Cliff, I hadn't thought of that. Seems by far the simplest solution. If I tie a half-hitch I should get half the voltage, right? :D :D

Larry, don't fret. If it happens at the breaker panel, I ain't doing it.:eek: I'm perfectly comfortable with running 110 everywhere, but the breaker panel is a deep mystery to me. But now I know what to tell the electrician I need and know if what he is telling me makes sense.

(What do you mean, don't use the same breaker? Didn't you, as a kid, replace any fuse with whatever you had on hand and then acted surprised when smoke came out? And what about copper pennies? Or am I dating myself?)

Steve Clardy
08-09-2006, 12:17 PM
Copper pennies. Hey! I remember that trick!

Kent Fitzgerald
08-09-2006, 12:47 PM
OK, you have a neutral, so you can use one hot and the neutral to supply 120V. As others have said, change to a 20A breaker. You could use a single pole breaker and abandon the unused hot conductor (cap it at both ends). You may need to use 12 ga pigtails to make the connections to the receptacle.

Jim Becker
08-09-2006, 12:51 PM
I did exactly this when I did my kitchen renovation...re-used the #10 wire that was already in place for one of the trashed Jennaire cooktops for a 120v circuit for the new gas range. It was just a breaker and outlet change. (And running a new cable would have been a pain due to access, so I was thankful to have the line already there)

Joe Pelonio
08-09-2006, 1:19 PM
Bob,

Yes. Turn 240 volt breaker OFF. Replace the 240 volt breaker with a 120 volt breaker. Use the black and white wires, if available. With the breaker OFF, wire the black wire to the 120 volt breaker and the white and ground to the neutral bar. Fold the unused wire back into the box on both ends - tape the wire ends. Be sure the breaker is OFF before wiring at the appliance end.

Larry
Rather than just taping place a wire nut on it and then tape.

Chris Padilla
08-09-2006, 1:29 PM
FWIW, #10 will work in a back-wired duplex outlet (normal 120 V outlet) but as already mentioned, if bigger than #10, you will need to connect a smaller gauge wire to the bigger one with appropriate-sized wire nut to fit the receptacle appropriately.

Oh, good luck tying a knot in #8!! :p ;) I would just cap it with a wire-nut and some electrical tape and do the same in the panel at the breaker. You might make a note in the panel as to what the wire with the cap is and where it goes if a future homeowner wants to use it or your memory fails yous 30 years from now! :eek:

Edit: Sorry, Joe, I typed out my post and submitted before seeing your post...great minds think alike?? :D

Cliff Rohrabacher
08-09-2006, 3:58 PM
Thank you Cliff, I hadn't thought of that. Seems by far the simplest solution. If I tie a half-hitch I should get half the voltage, right? :D :D

Half hitches will best attenuate the voltage as they can be tird infinitely (till the wire runs out).


the breaker panel is a deep mystery to me.

Oh stop it. The main panel is as simple as pie. Seriously no half hitches or anything so complex. Turn off the main breaker and everything on your side will be safe to work on. Once the main breaker os in the off position you can use the three wires that you normally use (Black, White, and bare) in exactly the same fashion as everywhere else save for a few minor exceptions.

Two rules for working the main panel:
1.) Don't double up on any one breaker, don't double up on the neutral bus bar (white wires go here).

2.) Don't treat bare (ground) and neutral (white) the same. There will be two seperate buss bars. One for ground and another for neutral (unless you have a brutally old or non-code main panel in which case swap it out - must have power company turn off power for a main panel swap out).

Black wires go to the breakers
White wires go to the neutral buss
Bare wires go to the ground buss

#12 wire can go to 20 amps max
#14 wire can go to 15 amps max

Never attach a smaller wire to a larger one unless it's breakered for the smaller wire. I wouldn't do it anyway.

All is right with the world

Panel installation:

Main panels have the ground and neutral bonded ("bonded" is the super secret electrical gee whizz code for "Connected together") .

For sub panels that are inside the main building or attached don't bond the neutral to the ground.

For sub panels in an out building (not attached) you must bond the neutral to ground and you must drive a copper stake in the earth as your ground. You should use a #4 or larger main grounding wire. I prefer driving the ground at least 10' deep but in some soils that is more vain hope than reality. Local code enforcement people will tell you what depth and what diameter the rod must be. Use copper or copper plated.



Didn't you, as a kid, replace any fuse with whatever you had on hand and then acted surprised when smoke came out?

I still do who are you kidding??


And what about copper pennies? Or am I dating myself?)

Yes the pennies made for the last decade or so are Zink with a 3-5 millionths of an inch thick electro-plating of copper. Zink melts faster at lower temperatures than Copper.

The new Zink pennies are graded to precisely fuse for 15 amps. You may stack them for higher amperages. I use 15 at a time and run my house on zip cord.

Norman Hitt
08-11-2006, 3:02 AM
For sub panels in an out building (not attached) you must bond the neutral to ground and you must drive a copper stake in the earth as your ground. You should use a #4 or larger main grounding wire. I prefer driving the ground at least 10' deep but in some soils that is more vain hope than reality. Local code enforcement people will tell you what depth and what diameter the rod must be. Use copper or copper plated.
.

Not in Odessa.........., the already installed underground conduit for my shop necessitates the installation of 3 lengths of 2.0 cable 115' long each, plus a bare ground wire of the same length, (seems like it said #6 wire minimum size for the ground wire, IIRC) from the 200 amp sub panel back to the main panel located on my wellhouse at the alley. (This is according to the City of Odessa permit dept, and they even gave me a handout drawing illustrating all of this), with specific instructions to NOT use an earth ground at the subpanel in the shop, and also to NOT bond the neutral and ground Buss bars in that sub panel, to prevent some form of Ground Loop, (or maybe it was Looped Ground).:eek: :confused: Heck, I thought Ground Loop was a screw up some Pilots manage to do in a Tail Dragger Airplane.:rolleyes::D

Note: I have no idea how these instructions relate to "Code", I just know it is how they require it to be done here. I guess every Permitting Jurisdiction must reserve the right to be "Different" in one way or another.:rolleyes:

tod evans
08-11-2006, 7:56 AM
Yes the pennies made for the last decade or so are Zink with a 3-5 millionths of an inch thick electro-plating of copper. Zink melts faster at lower temperatures than Copper.

The new Zink pennies are graded to precisely fuse for 15 amps. You may stack them for higher amperages. I use 15 at a time and run my house on zip cord.

:eek: :eek: :eek: caution...the electrical police will get you..

Rob Russell
08-11-2006, 10:13 AM
Note: I have no idea how these instructions relate to "Code", I just know it is how they require it to be done here. I guess every Permitting Jurisdiction must reserve the right to be "Different" in one way or another.:rolleyes:

Correctomundo. That's why they are called the "Authority Having Jurisdiction" and the AHJs can, and do, make local modifications to the code. The NEC is really a set of rules that most municipalities start from, but there is no US law that says a municipality even has to use the NEC as their base.