We don’t live in the Dark Ages anymore, and so we shouldn’t have to fumble around the breaker panel trying to find which breaker controls which outlet. With a tool like Klein’s ET300 Digital Circuit Breaker Finder, you just the plug transmitter in the outlet you want to disable, and scan your circuit breakers with the receiver until you find the right one.
Well, it isn’t quite as easy as that. This tool, and tools like it, get panned by customer reviewers, usually because they don’t take the time to read the instructions. When using a circuit breaker tracer, you first need to scan ALL the breakers with the receiver for it to learn the panel. Only after this step will the receiver beep and light up with a green arrow when you are over the correct breaker.
Klein says the ET300 is “microprocessor controlled for more reliable identification.” I’m guessing that means the transmitter sends out an encoded signal identifying it to the receiver. The transmitter can send a signal down wiring for distances of up to 1000 feet, which should be plenty for most residences.
The receiver is powered by a 9V battery and automatically turns off after approximately 4 minutes to save power. Although the Klein website shows the receiver naked, all retailers’ product pages show a version of the receiver with an orange rubber jacket.
Out of the box, this tool only works for outlets, but you can buy a ~$12 adapter kit (Klein model 69411) that allows you to plug the transmitter into a medium base light socket. The optional adapter kit also comes with a 2-prong outlet and alligator clip adapter. You could also buy a light socket plug adapter for ~$2 at the hardware store.
You can find the ET300 at Amazon for about $40-42 with free shipping (if you order from Amazon directly), or you can pick it up for about the same price at Home Depot.
It is important to note that the ET300 only works with 90 – 120V outlets and breaker systems.
There are a couple of similar models by Extech ($35 via Amazon), Triplett ($30-40 via Amazon), and Amprobe ($30 via Amazon). The Extech is a little different, as their transmitter serves double duty as a GFCI outlet tester.
If you live in an older house that has suffered years of renovation, finding the right circuit isn’t always a matter of reading the labels on the breakers. Previous owners probably left useful notes like “Andy’s room,” or “Rec room” next to the breaker number, but trying to figure out who Andy was or why he slept in the basement isn’t your first priority.
When you actually throw the breaker to “Andy’s room,” you might find find it also controls the microwave, the small bedroom, the garage lights, and every outlet in the room except the one you are trying to turn off.
The last time I had to replace some outlets, I enlisted the help of my 7 year-old son. He stayed up stairs while I went downstairs to the panel. He means well, but when I yelled to ask him if the lights on the outlet tester went off, I’d hear something about the microwave clock and have to run upstairs anyway to hear what he was trying to tell me. This went on about 3 or 4 times.
The way I see it I have three options for next time. First, I could spend half a day trying to label the panel correctly, which is not very likely. Second, I could play the same shouting and running game when I need to turn off a circuit (the cardio from doing the stairs might do me some good.) Or third, I could buy a circuit breaker finder and take some of the stress out of my DIY projects.