Is there a tester that can check which outlets are on the same circuit?

Question

Basically what I want to know is if there is some sort of testing device you can plug into different outlets that will tell you if they are on the same circuit, and will it only test two at a time or can you do three or more? All without using the circuit breaker panel.

Answer 1

Yes: These are called "Circuit Breaker Locators" they work by impressing a low power radio frequency onto the AC line. A handheld receiver is used to sniff out the signal. You can isolate and locate a specific circuit breaker within a panel while the circuit are powered. These sniffer is noncontact (unlike an Ohm or Volt meter) You could use this device to sniff out the signal at other AC outlets on the same circuit...

Answer 2

I'm not so sure the device joe is talking about exists, or more precisely, such a device will not be able to tell you if the outlets share a breaker or are on 2 parallel breakers. First off, all the neutrals short together in the breaker panel, so they are useless. As for the hots, it would be easy to determine if 2 outlets are on the same leg of the incoming 240 (each of these 2 legs makes a 120 to neutral), but to determine if the are on the same breaker isn't quite that simple. Joe, do you have a link?

And of course, an ohmmeter is no good unless you first turn off every breaker in the panel.

Mark, I've heard of the devices you mention, but the question includes "All without using the circuit breaker panel."

Answer 3

Yes. It features a signal generator which is either plugged into an outlet or attached (ONLY by a professional) onto the circuit breaker. When the receive is plugged into an outlet, the lamp lights if on the same circuit.
These may be available in your logal electrical supply store.

Answer 4

It's called Ohmometer.