How to Use a Circuit Breaker Finder

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Finding the correct circuit breaker to turn off or the right fuse to remove is a snap with the Sperry circuit breaker finder.

Have you ever tried to locate the circuit breaker controlling the branch circuit that you want to work on? If you have a relatively new home, the circuit directory may be correct so finding the right breaker is a snap. The circuit directory on breaker panels in older homes is illegible or missing. The easiest way was to plug a radio into the receptacle, turn the volume all the up and then turn the breakers off one at a time until the radio stops blaring. Now there is a better way, the electronic circuit breaker finder. I was introduced to this gem 10 years ago, and I am still using the same A.W. Sperry CS500A model that I bought 10 years ago. There are newer models available, but this one has proven dependable and indestructible.

The A.W. Sperry CS500A Circuit Breaker Finder

The A.W. Sperry CS500A Circuit Breaker Finder is a Two-piece set-a transmitter and a receiver. The transmitter plugs into the energized outlet. The receiver, powered by a 9-volt battery beeps when it passes over the circuit breaker or fuse protecting that branch circuit. The neat thing about this tool is that it is available at better hardware stores and most home centers. It is also relatively inexpensive at less than $40. Every DIY electrician can afford to have one of these time savers in his or her tool kit.

How to Use the CS500A

The CS500A is so easy and intuitive to use that you really do not need to read the instructions that came with it, but read them anyway. Get into the habit of reading all the literature that comes with any tool that you purchase.

  • Plug the transmitter into an outlet on the branch circuit that you will be working on. The yellow LED (Light Emitting Diode) will light up, indicating that voltage is present in the receptacle.

  • Place the receiver in front of the transmitter and turn the on/off switch on and rotate it to maximum sensitivity. The LED on the receiver will remain on, and a steady beep will come from the built in speaker. Slowly reduce the sensitivity until the LED starts to blink and the beep rate is about six beeps per second.

  • Move to the circuit breaker panel or fuse panel. Place the receiver, so it is at a 90 degree angel to the panel, and move it slowly up and down the rows of breakers or fuses.
  • Slowly decrease the receiver's sensitivity by turning the knob away from the panel's front until the receivers beep over only one circuit breaker or fuse. After you have located the right breaker or fuse, turn the breaker off or remove the fuse. The receiver will stop beeping.
  • Double check that you have turned the right breaker off or have removed the right fuse by checking the LED on the transmitter. If the LED on the transmitter has gone out, you have turned the right breaker off or have removed the right fuse.
  • If you are working with a light fixture, screw an adapter into the light fixture's socket and plug the transmitter into the adapter.



Jerry Walch
Posted on Feb 7, 2012
Posted on Feb 7, 2012
Johnny Dod
Posted on Feb 8, 2011