Circuit Tracing

Thread Starter

tbhockeystud

Joined Sep 11, 2012
2
I purchased a foreclosure property and my breakers were all removed. To save myself some cash and label the box correctly, what is the easiest way to trace the individual circuits? Thanks.
 

MrChips

Joined Oct 2, 2009
30,805
You can inject a signal or voltage into the wires from either end and trace the signal at the other end or along the walls.

Or you can short the ends of the wires and locate the other end with an ohmmeter.
 

Jeffnars

Joined Sep 9, 2012
19
This is how I would do it.

Go to your neighbours house can't check whats labeled in their consumer box (breakers)

That way you know what your looking to locate and what your going to label the breakers up as.

With this you can then use logical thinking. If you know there's a light circuit. With all the power isolated put a shorting wire between the live and negative. Go back to the breaker box and bell the wires out using a multimeter.

Once you have found the wires. Place the correct breaker suitable for the job and label it up. It will get easier as you go as ull reduce the amount of wired each time u place in a breaker.

REMEMBER to remove all the shorts. :)
 

MrChips

Joined Oct 2, 2009
30,805
If you don't want to make too many trips around the house, get a whole bunch of standard value resistors, for example 100Ω or 1kΩ.

Short a pair of terminals at the outlet with one resistor,
two resistors in series at the next outlet (in a different room),
three resistors in series at the third outlet etc.

At the panel box you can locate which is which on one trip.

If you want to find out which outlet is on which circuit - do the opposite:
Put the resistors where the panel box is supposed to go and then hunt around the rooms with your ohmmeter.
 

ErnieM

Joined Apr 24, 2011
8,377
If you have to ask I would recommend you hire an electrician!

However, first off be very very careful as you can kill yourself poking in the breaker box. Make sure you know what you are touching before you touch it. Get yourself a meter to measure wires are truly dead before you touch them. You can get a meter from Radio Shack for not much money.

MY box has a main breaker before all the others. That matches the "service" you have, and the local utility may be able to tell you that number.

After you get the main breaker in, you could just buy a small breaker and install it on each branch. Go around the house with a lamp to see what outlets are getting power. Any ceiling light fixtures and the like will need working bulbs to test.

You might find some circuits doing an instant trip: these may be things like a water heater or a stove. Those branches will have heavier wire so you should have some idea what they are.

More important is sizing the breakers once you know what they do. This is done by observing the wire size used on each branch.

Being a somewhat pedantic twit I would check each and every outlet and light to insure some nitwit electrician didn't go cheap and use undersized wire anywhere.
 
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