Go Back  DoItYourself.com Community Forums > Electrical, AC & DC. Electronic Equipment and Computers > Electrical - AC & DC
Reload this Page >

Microwave is listed at 13A, is a dedicated 15A circuit enough?

Microwave is listed at 13A, is a dedicated 15A circuit enough?


  #1  
Old 03-13-03, 05:35 AM
M
Member
Thread Starter
Join Date: Aug 2002
Location: Indiana
Posts: 131
Upvotes: 0
Received 0 Upvotes on 0 Posts
Microwave is listed at 13A, is a dedicated 15A circuit enough?

Simple question, but I'd like someone to confirm this. My non-built in microwave (counter recepticle it's plugged into) shares the same 15A circuit with the kitchen lights, and I'm tired of seeing them dim (and wondering if the house will burn down) every time I cook something.

Further investigation revealed a 15A breaker that services nothing more than a rarely used recepticle in the basement. What I'd like to do is take that recepticle off the breaker and tie it in to one of my basement circuts, then run 12/2 from the recepticle back to the vacated breaker.

Is this okay? Or should I apply a factor of safety and replace the 15A breaker with a 20A?

Oh, and should I throw the main when I'm connecting/disconnecting from the breaker?
 
  #2  
Old 03-13-03, 05:57 AM
M
Member
Join Date: Feb 2003
Posts: 475
Upvotes: 0
Received 0 Upvotes on 0 Posts
Not quite sure I understand. Are you saying you're going to move the microwave to the basement? First you talk about a microwave in the kitchen, and then you move on to a receptacle in the basement that you plan on rewiring.

If you are saying that you plan on rewiring the kitchen (microwave) receptacle with 12/2, and are messing with the basement receptacle because you don't have any spare spaces in the panel or don't want to put in a new breaker, then you have a couple of things to consider:

1. How are you going to get the new 12/2 wiring into the box behind the microwave? What wiring is in that box now? How many cables and what guage (assuming #14 since it's on a 15 amp breaker)? What do you plan on doing with the wiring currently in the box? It may be best to cut in a new receptacle beside the existing receptacle.

2. If you run the 12 guage from the receptacle all the way to the panel, you will most certainly want to put it on a 20 amp breaker. Kitchen counter receptacles are supposed to be on 20A circuits anyway. If you have any mix of 12 and 14 guage wiring on a circuit, then the circuit must be on a 15 amp breaker. Instead of messing with the stuff in the basement, can you install a new 20A breaker in the panel? If your panel has any unused knockouts in the cover you probably can. If not, and you need the space where the 15A breaker is, I would remove the wire off the breaker in the panel and splice it to the wire on the breaker for the other basement receptacles (assuming they're both 15A circuits) and pigtail to one of the breakers. You can then replace the other breaker with a 20A for your kitchen receptacle.
 
  #3  
Old 03-13-03, 07:03 AM
M
Member
Thread Starter
Join Date: Aug 2002
Location: Indiana
Posts: 131
Upvotes: 0
Received 0 Upvotes on 0 Posts
Alright, here's some more info. Guess it wasn't a simple question.

1) The recepticle sits next to a wooden "microwave stand" that's technically isn't a countertop, nor is it attached to a countertop. The only thing that ever makes sense to go here is a microwave. As of right now, the recepticle is served from above via the kitchen ceiling lights.

1A) I'm not sure the NEC requirement for countertops necessarily applies to this recepticle. I do have two circuits for my countertop recepticles.

1B) A little while ago, I discovered this recepticle did not have a ground wire nor AC/conduit, so I drilled some holes and ran a 12-gauge green wire all the way back to the panel (per NEC for separate EGC for recepticle replacement). Yes, I should have run fresh 12/2 and put the recepticle on a separate circuit back then, but this was before I noticed the dimming.

1C) Nothing is downstream of this recepticle, I could place wirenuts over the old wires (which I think are 12, actually) or loop & tape them and run the 12/2 in the path the ground wire is in now.

2) Yes, I do have two slots for new breakers. They're both earmarked for future projects (I'm planning on converting the attached garage into a family room and converting its attic into a master bath). I'd prefer heading into that project with two breakers to spare and not have to think about recombining circuts or replacing my electric dryer with a gas one. . .

2A) If I were to reuse/replace the existing 15A breaker, the 14/2 that feeds the lone basement recepticle would be removed from the panel and connected to a basement junction box that's much closer to the recepticle.

2B) Does NEC require that circuits comprised of entirely 12-gauge wires have a 20A breaker?

Thanks for the help.
 
  #4  
Old 03-13-03, 07:12 AM
M
Member
Join Date: Feb 2003
Posts: 475
Upvotes: 0
Received 0 Upvotes on 0 Posts
1C. Either tape up and leave the cable in the back of the box or if you know where the other end of the cable is you can cut it on both ends and push it out of the boxes (I would leave it as you said).

2. Can you put tandem (piggyback) breakers in the two open slots to make room for (4) circuits. There should be a wiring configuration on your panel somewhere that will provide that information. If it is a 40 circuit panel with 40 spaces, then a tandem breaker cannot be installed.

2B. No. There is nothing to prevent you from putting a circuit composed entirtely of #12 wire on a 15amp breaker, but a single pole 20A breaker will probably only cost about 5 bucks so you may as well change it.
 
  #5  
Old 03-13-03, 08:12 AM
hornetd's Avatar
Member
Join Date: Aug 2001
Location: Maryland
Posts: 646
Upvotes: 0
Received 0 Upvotes on 0 Posts
Re: Microwave is listed at 13A, is a dedicated 15A circuit enough?

Originally posted by mrchris
Simple question, but I'd like someone to confirm this. My non-built in microwave (counter recepticle it's plugged into) shares the same 15A circuit with the kitchen lights, and I'm tired of seeing them dim (and wondering if the house will burn down) every time I cook something.

Further investigation revealed a 15A breaker that services nothing more than a rarely used recepticle in the basement. What I'd like to do is take that recepticle off the breaker and tie it in to one of my basement circuts, then run 12/2 from the recepticle back to the vacated breaker.

Is this okay? Or should I apply a factor of safety and replace the 15A breaker with a 20A?

Oh, and should I throw the main when I'm connecting/disconnecting from the breaker?
There is nothing wrong with your plan for the kitchen receptacle except the size of the breaker. Since this receptacle is in a food preparation area and is not dedicated to a single appliance it must have a twenty ampere circuit supplying it.

Proceed as follows:
Cap off the old circuit with wire nuts.
Run new circuit back to panel using 12/2 w GND cable.
Replace existing breaker with twenty ampere breaker.
Remove existing basement receptacle cable from panel.
Connect new cable from kitchen receptacle to panel cabinet.
Tie new kitchen circuit into panel's bonded buss bar, grounded conductor buss bar (these may be the same buss bar if your panel is also your service eqquipment), and the new breaker.

Your microwave problem should now be solved. If you are not practiced at panel work you should definitely deenergize the panel while installing the breaker and connecting the new circuit.

In regards to your future remodeling plans let me ask a few, hopefully cogent, questions.
What size is your present service in amperes?
Does your panel have more than one main breaker?
How many full sized slots does your panel have? In other words how many full sized single pole breakers would your panel hold if that was the only type of breaker in it?
Does the panel schedule have letters after some or all of the breaker numbers such a,b f,r or l,r?

With the answers to those questions I could provide more intelligent advice.
--
Tom
 
  #6  
Old 03-13-03, 12:32 PM
M
Member
Thread Starter
Join Date: Aug 2002
Location: Indiana
Posts: 131
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks guys. I may connect to the 15A for now and have somebody else (like my dad) do the breaker. Gotta love NEC.

In regards to the future remodel, well, this will probably be 2-3 years away. I'm storing stuff in the garage now, I haven't even had a preliminary discussion w/ a contractor. It's a 100A panel, and I can't tell you how many slots/breakers I have right now as I'm not at home.

I only brought it up to say I'm trying to save my two free slots for a "rainy day," and would prefer to work with my existing breakers/slots. The remodel will push the GLA to about 1650 sf, with a 900 sf basement. I wouldn't be afraid to spring for a 200A panel if the project dictates it.
 
  #7  
Old 03-17-03, 05:56 AM
M
Member
Thread Starter
Join Date: Aug 2002
Location: Indiana
Posts: 131
Upvotes: 0
Received 0 Upvotes on 0 Posts
Well, it's done. Fishing 12/2 AC through through a plaster/lathe wall proved to be more challenging than I thought.

The 15A breaker will get swapped out the next time my dad visits me.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: