[BrynMcbain]

Boy I stepped in it this time.
I am remodeling my own kitchen. I decided to group the new wall oven in a cabinet (to be built) with a built in microwave I just bought on eBay.
I have the dedicated 220 wiring already in place for the oven.

The problem is the microwave circuit. My old microwave was under counter and was on a dedicated 110v line, 20A feed by 12ga romex.
The new beast is 1200 Watts and wants a 220V dedicated circuit.

Question. Can I take the existing circuit, go back to the service panel and install a 220v breaker, tape the white wire (say red), and thus convert the 110v circuit to a 220?
If I do this, what size breaker should I install?
Thanks for any advice in advance.

[Ira]

No you can't, that wire goes to feed other places... Run a new line... FIRE BURNS

[stanfortyman]

No you can't, that wire goes to feed other places

Ira, what mkes you say this?? Bryn specifically staes that this is a DEDICATED 120v circuit for the micro.



Bryn, if you are absolutely certain this is a dedicated circuit you certainly CAN do exactly as you propose.
You need to match the receptacle to the plug on the new micro. It will be either a 15a or 20a, 250v plug. Use the matching receptacle and breaker.
Your #12 wire can be used for wither 15a or 20a circuits.
I'd also use a permanent marker instead of tape. Tape does not last on such small wire.

[BrynMcbain]

Ira, Stan was correct. The existing circuit is a home-run directly back to the main service panel.
Both of you --- thanks ever so much. It's nice to have feedback when you are going it alone.

I will proceed, now (phew).
BTW assuming the new microwave now draws oh about 5 1/2 A (say it's 1200Watts on a 220V line), wouldn't a 10Amp 220V breaker do since I do not intend to ever have anything other then the microwave on this circuit? I see little purpose for throwing on a 15A or 20 A breaker which would never trip in that case unless the microwave was already smoking and on fire.

Oh and since I have you guys ear(s), The rules regarding outlets in a peninsula in the kitchen (assume everything is wider then 12"), state no point on the counter can be > then 24" from an outlet, then it goes on to say something like "...but if you have a peninsula, you only need one outlet to service the entire (unbroken) counter. I understand the "breaks" they refer to (in my case the cooktop). I also understand the concerns with "under counter" outlets. (kids pulling fry pans onto their heads etc (---Shouldn't we just let Darwin's rules apply here though :) )

But if I have the entire rightside of the cooktop peninsula raised up 4" higher then the cooktop, BUT, it is a flat unbroken 32" counter for the next 6 feet, it should only require one receptacle correct? And this one can be on either end correct?
Why did I raise it you might ask? Because I wanted to surround the cooktop with a right edge and I figured since I was hand fashoning the cabinets, why not continue that height all the way around. That way it gives me a nice area for bar stools on the non-kitchen side. (and I get 4 extra inches of cabinet space too. Trying to get the rail lines even around the kitchen though has been a trying experience but not germane to this forum so I'll shut up.

[Washington1]

the new beast is 1200 Watts and wants a 220V dedicated circuit.

Please post the model number and manufacture

[stanfortyman]

I will proceed, now (phew).
BTW assuming the new microwave now draws oh about 5 1/2 A (say it's 1200Watts on a 220V line), wouldn't a 10Amp 220V breaker do since I do not intend to ever have anything other then the microwave on this circuit? I see little purpose for throwing on a 15A or 20 A breaker which would never trip in that case unless the microwave was already smoking and on fire.

Your logic on this is flawed. The breaker does not protect the appliance. It protects the branch circuit.
What you propose could be applied to any small appliance in your home.


Like I said, as long as the wire is appropriately sized, match the breaker and receptacle to the appliance plug.

[KISS]

A 10A breaker will probably be just fine. It's best, though to see what the manufacturer wants.

True, it really doesn't matter, because internally the micowave generally has an internal fuse.

It does matter that the breaker does not exceed the rating of the wiring used. In your case 20A.
If a 10A breaker is cheaper, then by all means use it.

[stanfortyman]

Show me a 10A "standard" breaker.

[Ira]

Sorry I didn't see it as a dedicated line. The microwave has a fuse in it.