Identifying circuit breakers

Thread Starter

ApacheKid

Joined Jan 12, 2015
385
OK so not electronics per-se but I must post this somewhere.

Is there any kind of tools or technologies that can simplify the identification of exactly what parts of my house are controlled by which circuit breaker?

I have two large panels at my house one is outdoors and is where the master power switch is, that turns off/on all power to the building.

Another equally large panel is in the garage and seems to be similar (but has no master power switch) but is for the attached "casita" which is like part of the same physical building but isolated, having its own door (like a place a relative could live).

So there are switches for "general lighting" and "small appliances" and "air handler" etc etc.

My workshop (which I'm setting up and equipping these past few months) is part of the Casita, its one of three garages on the property.

Well I need to adjust some smoke alarm wiring in the garage's ceiling as part of some work I'm doing getting the workshop set up, but I can cut the power to it.

Yesterday I tried switching off all kinds of stuff but none of them led to power in that smoke alarm ceiling connector, being cut, today I'll shut off the entire building and be done with it, but I always hate doing that and like to avoid it.

So are there tools that make this easier? doing this even with two people seems like a huge pain in the ***.
 

Tonyr1084

Joined Sep 24, 2015
5,969
Perhaps you DID answer your own question. Somewhere those detectors are on a breaker. But for determining when power is cut and I'm all alone - I hook up either a radio or a vacuum cleaner and turn them on. When I hit the breaker that shuts that circuit off I mark it. Then I go around testing all the outlets for power. When I know which outlets are controlled by which breaker - I have the answer I need. It IS a pain. Having to reset clocks and such. But it's doable.
 
Is there any kind of tools or technologies that can simplify the identification of exactly what parts of my house are controlled by which circuit breaker?
Your hands and a tick-tracer. Switch off a circuit, probe things with the tick-tracer.

You can try a circuit tracer, but those tend to be hit or miss in my experience unless you can connect them directly to the conductors being tested. 50 feet or so seems to be their effective range with the inductive clamps. Completely useless for finding individual breakers. Locating which panel out of 20 it's fed from is the best you can realistically hope for.

Otherwise there's always the oldschool way as long as you don't have an FPE or Zinsco panel.:p
 
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Tonyr1084

Joined Sep 24, 2015
5,969
My breakers were also poorly marked. I made a shorted plug and when plugged into a receptacle the breaker did its job. I needed to go up and down the stairs each time because my wife was afraid of the sparks.
Not something I would recommend. The sparks are hot and can fall down inside the wall where they COULD start a fire. But at least then you won't have to be running up and down the stairs. Just up once. And out.

As for the trick - much of my home is 12 gauge 20 amp wiring to all the outlets. Blowing a 20 amp breaker is going to produce a lot of light and excitement. AND the outlets in my home are the 15 amp design, NOT the 20 amp outlets. I have no desire to go through the entire house replacing them. Two days ago I replaced a light switch with an "Occupancy" switch. (motion detector) The steel box that was in the wall was not deep enough to accommodate the new switch so I had to cut open the wall and replace the box with a deeper one. Also had to run new power, as the old power was "Interrupt" wiring. Also called by other names, I'm not sure which.

But instead of using a dead shorted plug, just use a vacuum cleaner. Or if you really just want to blow the breaker, plug two hair dryers into the same outlet and turn them both on high. 1500 watts each (3KW) will draw 25 amps, and you don't burn up any plugs or receptacles. Come to think of it - I might just do that. The wife has a curling iron and a hair dryer. I bet that would overload a 20 amp breaker. Certainly would overload a 15 amp breaker.
 
Also had to run new power, as the old power was "Interrupt" wiring. Also called by other names, I'm not sure which.

[...]

if you really just want to blow the breaker, plug two hair dryers into the same outlet and turn them both on high.
Switch leg?

And again, hope you don't have a sh*tty FPE or Zinsco, etc. panel. What's the statistic again? 33% of tested FPE Stab-Loks just sit there and burn instead of tripping? These evil little things. Orange handle - replace it. Ran across a maintenence department once with a whole drawer full of brand new old-stock Stab Loks ready to install. At least all the electrical rooms were lined with asbestos. :p
 

Tonyr1084

Joined Sep 24, 2015
5,969
Yeah, I have the "Magnetrip type O" Zinsco breakers. Expensive as all hell too.

One thing for sure, if I turned on two hairdryers and they didn't blow the breaker I'd be on that like white on rice. Like crunch on Laura Scudder's Potato Chips. You remember those chips? "Laura Scudder's Potato Chips are the noisiest chips in the world."
 

SamR

Joined Mar 19, 2019
3,405
First turn on all the switched lights, fans, etc. Second test each receptacle with a plug-in tester that lights up if hot. This eliminates any dead bulbs or bad receptacles. Third turn-off breaker. Then see which lights went out and repeat the receptacle test. Trick is many breakers may serve more than one room or area. Also note that many breakers are mismarked as to area served.

EDIT: Another good test is to remove the panel front cover and do an IR scan for hot spots.
 
Looks like a basic cat-and-mouse circuit tracer. Like I said, they're hit or miss. Useful for getting in the ballpark or finding the right panel but very rarely will they land you on exactly the right breaker unless it's a very short run. In a residence it's faster and easier to just guess and check. Not like you're worried about shutting off power to something important at an airport or something.
 

Thread Starter

ApacheKid

Joined Jan 12, 2015
385
It would be so helpful to have a spreadsheet that has every room and area, then for each of those every kind of connection (wall outlet, light socket, smoke alarm etc) and then for these the number identifying the circuit breaker.

I created something like this once but it was a small building, not many rooms etc.
 

Tonyr1084

Joined Sep 24, 2015
5,969
Now you have me reconsidering replacing the whole breaker box. Mine doesn't even have a ground bar in it. And having replaced all the copper piping with PEX Tubing, I've had to add ground wiring every place I've touched the electricity. The original 12/2 wiring does not have a ground lead in it. The whole basement has been rewired WITH grounds. The jetted tub with built in water heater is on GFCI outlets that did not trip when tested. Had to install a ground rod just outside and run a dedicated ground just for that.

To be honest, my house wiring is a bit of a hodge podge.
 
Might be a good opportunity to just go through your panel and label everything.

Smokes are usually piggy-backed off of one of the lighting circuits or whatever feeds the living room. Bathrooms sometimes share lights with the rest of the house unless they are piggy-backed off of a bathroom receptacle - bathroom receptacles can't feed anything outside the bathroom. Dishwasher and garbage disposal usually share a multiwire branch circuit. Two small appliance branch circuits for the kitchen. One more if your microwave is fastened in place. Range and clothes dryer, plus a laundry area receptacle on it's own. Newer garages have their own circuit.

Mine doesn't even have a ground bar in it.
That's normal for a service panel. Neutral and ground are always bonded together at the service equipment to provide ground reference and a return current path for ground faults. Everywhere else they should be strictly separate. As for the rest of that wiring... oof. I hope you bonded that ground rod to the rest of the grounding electrode system and the panel, otherwise it won't do much good in the event of a ground fault. Sounds like you could really benefit from a professional inspection.
 
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There is like a $50.00 USD device that you "plug in" to a receptical and you go to the panel and locate the breaker. they m might be battery backed up too.

If they are known to be on GFCI's, 20 mA from HOT to ground should trip it.
 
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