A.W. Sperry CS550A Circuit Breaker Finder Electrical Tool Reviews

AW Sperry CS550A Circuit Breaker Finder

When it comes to identifying circuit breakers in an existing home, using a circuit breaker finder may be the easiest way to make a difficult and tedious project as simple as possible. By using a transmitter and receiver, a circuit breaker finder like the AW Sperry CS550A can quickly and easily identify individual branch circuits at the panel box without interrupting power. This method is quite simply the easiest, if not the best way to accurately locate circuit breakers. The AW Sperry CS550A circuit breaker finder is compact in size and extremely easy to use and locates both AC Breakers and Fuses. You simply plug it into the wall outlet and the receiver issues a distinctive signal (audibly and visibly) when it passes over the correct breaker. It doesn’t interfere with sensitive electronic equipment and takes only one 9V battery to operate (not included).


Using the System – Calibration

To calibrate the system you simply install a 9V battery in the receiver. There is a rocker switch which powers on the receiver and a brightly lit LED indicates the battery is good. After you plug the transmitter into a powered electrical receptacle/outlet, its LED will flash and a beep will sound at a rate of 7Hz (7 times per second). Place the target tip of the receiver against the back of the plugged-in transmitter and you will note that the two lights and the beeper will flash in sync. While holding the receiver there, press and hold the calibration switch. The receiver then stops after a second or two. Release the calibration button and the beeps and LED will begin again. Calibration is then complete once you power off the receiver.

To locate a breaker, you first have to go through a calibration process. To begin, simply plug the transmitter into an AC outlet and take the receiver to the circuit breaker panel and open the cover. After turning on the receiver, place the target on the tip firmly against the first circuit breaker in the panel. Press and hold the calibration switch while moving the receiver across the circuit breakers. When the receiver responds to a circuit breaker stop moving it until the receiver stops responding, then continue moving the receiver to the next breaker.

Using the AW Sperry CS550A Circuit Breaker Finder – Locating & Verifying

During the calibration process, the receiver may respond to more than one of the circuit breakers in the panel, each time this occurs, wait for the receiver to stop responding before moving to the next circuit breaker. After scanning all the circuit breakers in the panel release the calibration switch and rescan the circuit breakers. Only one breaker will now produce a response in the receiver.

While continuing to hold the receiver against the identified breaker, turn off the breaker. This removes power to the remote transmitter and the receiver will cease producing a response. This is how you confirm that the transmitter is no longer receiving power.


Turning off the AW Sperry CS550A circuit breaker finder receiver resets the calibration circuit and preps the device for another scan. We found it quite easy to move through a home in little time and identify all of the correct circuits tied to any particular breaker. Of course, “little” is a relative term and you can expect to spend an afternoon on a project of this sort if you are attempting to identify the circuits in an entire breaker panel. In terms of value, this is an incredibly effective and inexpensive product to have in your arsenal and it’s perfect for the do-it-yourselfer or renovator. There are certainly better, more robust products available for journeymen and electricians who do this every day.

The kit is UL listed to both US and Canadian standards.

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