Determining Outlets on Which Circuits
 

I just moved into a new house and am trying to figure out what outlets belong to which circuit. The circuit breaker labels are old and wrong and I would like to label them properly, but more importantly, I am trying to figure out which outlets in the kitchen are on different circuits. Whenever we use the microwave, somewhere between the second and fourth minute the circuit blows, and that turns off the oven, hood, fridge and anything else that I haven't realized yet. I want to move the microwave based on what outlet it will work on.

Is a circuit breaker finder the only way to do that? Is there another tool I can use? I don't want to turn off circuits to do it, so is there a tool that will work for? I don't know if the CBF needs the circuit on or off.

Here's an idea of what I'm thinking, but I don't know what specs to look for: Klein Tools CBF

I know you say you don't want to turn off the breakers, but that really is the best way. The method I use in a new house is:
(1)draw a simple floor plan noting each fixture.
(2)turn off all breakers.
(3)turn on one breaker at a time.
(4)use a circuit tester or night light and test each fixture.
(5)mark the floor plan map with the circuit when each fixture is on.
(6)return to #2

It can take a while but only once.

If you have a single outlet you are trying to determine, you can use a radio or alarm clock plugged into the outlet (take out the battery backup if using an alarm clock). Set the device to make noise, and flip breakers until the noise stops. (I have a small X10 module with an annunciator that I use for this purpose. I can hear it downstairs in the laundry where my panel is, even if the device is upstairs in a bedroom.)

You might rethink the idea of not turning off the breakers to test; it really is the most effective way. Commercial circuit testers can be very confusing to use, most transmit a signal on the circuit you are testing, but signals can cross to other circuits where the conductors come into close proximity of each other.
I think that you may find it wise to invest in new circuits for your kitchen, a minor rewiring job. Your fridge, microwave, and other appliances should have their own circuits, as most will draw large currents when compressors, transformers and motors start up. You could lose a fridge full of food, for instance, if a breaker trips and you don't notice it.
If you are testing individual receptacles, be aware that it is possible that the top and bottom receptacle on the same device may be electrically isolated from each other, and may be wired to two separate breakers. This is called a "split receptacle" and there are rules as to how they are physically wired, and how the breakers are installed and marked. The breakers usually must be side by side, with the toggles mechanically tied together. But, in an old DIY type install the rules may not have been followed closely.

Thanks for the replies guys. I wanted to check and notate all of the circuits before we moved in, but with packing, moving, unpacking being the priority, that didn't happen. The reason why I don't want to be shutting everything down is because there are 4 other people in the house and we all have different and somewhat eratic schedules. I also have certain things to worry about like if something is recording on the DVR, or if someones computer is on without files being saved. If some of the other people in the house happen to take a weekend trip, I will definitely make sure they shutdown sensitive items so I can do the project.

@hamsterpower: That was the plan, even though it will take a while (maybe my girlfriend can help me out). I like the drawing a house plan, then I can tape to the inside of the circuit breaker box door for later reference.

@where2: I like that idea. I think I might do a modified version of that for now. When that circuit blows again, I'll mark which breaker it is and leave it off while I go and try turning a night light on at the suspected outlets.

@herlichka: I didn't realize the complexities of the tester, I think I'll scrap that idea. Unfortunately, even though it may be a minor job (especially since one member of the household is an electrician), we are renting, so we can only do so much. It would be really nice and probably safer, but we will have to work with the landlord (don't get me wrong, that is possible, they're not like what you think of when you hear 'landlord'). The chances are pretty high for split receptacles. I know there at least two in two different bedrooms. Not sure of the quality of work that was done unfortunately.

Buy a clamp on amp meter instead . Take something like a corded electric drill and an assistant .

Plug the drill into an outlet you want to rest . Have the assistant repeatedly press the trigger on the drill , turning it off and on . Start checking the amperage on the single pole Circuit Breakers . When you find the one that shows a current fluctuation in sync with the sound of the drill , you have found that outlet . Go to the next outlet and repeat . Continue until you have all the CB's traced out .

It takes some time , but you have not turned any CB's off .

God bless
Wyr

Pretty easy to do. Make a trip to Harbor Freight and pick up one of these. Circuit Breaker Detective

Then pick up an edison base to 110v adapter to use it in light sockets.