---
product_id: 10938836
title: "Sperry Instruments CS550A Circuit Breaker Finder, Quickly Locate AC Circuits/Fuses, Visual LED, Plug Style Transmitter/Auto-Sensing Receiver, 120V AC, Yellow"
brand: "sperry"
price: "$79.02"
currency: USD
in_stock: true
reviews_count: 8
category: "Sperry"
url: https://www.desertcart.us/products/10938836-sperry-instruments-cs550a-circuit-breaker-finder-quickly-locate-ac-circuits
store_origin: US
region: United States of America
---

# 120V AC operation Bright LED visual indicator Audible alert for precise locating Sperry Instruments CS550A Circuit Breaker Finder, Quickly Locate AC Circuits/Fuses, Visual LED, Plug Style Transmitter/Auto-Sensing Receiver, 120V AC, Yellow

**Brand:** sperry
**Price:** $79.02
**Availability:** ✅ In Stock

## Summary

> ⚡ Find your circuit, own your space — no guesswork, just precision!

## Quick Answers

- **What is this?** Sperry Instruments CS550A Circuit Breaker Finder, Quickly Locate AC Circuits/Fuses, Visual LED, Plug Style Transmitter/Auto-Sensing Receiver, 120V AC, Yellow by sperry
- **How much does it cost?** $79.02 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/10938836-sperry-instruments-cs550a-circuit-breaker-finder-quickly-locate-ac-circuits)

## Best For

- sperry enthusiasts

## Why This Product

- Trusted sperry brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Dual Alert System:** Simultaneous audible and LED signals guarantee you never miss the right circuit.
- • **UL Listed Reliability:** Certified for safety and performance at 120V AC, trusted by pros and DIYers alike.
- • **Compact & User-Friendly:** Plug-in transmitter and auto-sensing receiver make complex electrical tasks effortless.
- • **Safe Around Sensitive Tech:** Non-intrusive design ensures zero interference with your delicate electronics.
- • **Pinpoint Circuits in Seconds:** Quickly identify the exact breaker or fuse without interrupting power.

## Overview

The Sperry Instruments CS550A Circuit Breaker Finder is a compact, UL-listed tool designed to quickly and safely identify individual AC circuits or fuses at 120V without power interruption. Featuring a plug-style transmitter and auto-sensing receiver, it uses both audible alerts and bright LED indicators to ensure accurate circuit location, making it an essential device for electricians and home professionals aiming to eliminate guesswork and mislabeled breakers.

## Description

Product Description Sperry Instruments CS550A Circuit Breaker Finder, Quickly Locate AC Circuits/Fuses, Visual LED, Plug Style Transmitter/Auto-Sensing Receiver, 120V AC, Yellow From the Manufacturer Circuit Breaker Finder. By using a transmitter and receiver, this circuit breaker finder quickly and easily identifies individual branch circuits at the panel box without interrupting power. It is the best way to accurately locate circuit breakers. They are compact in size and extremely easy to use. UL listed to both US and Canadian standards. Locates AC Breakers or Fuses. No need to interrupt Power. Distinctive Signal, Audible and Visual Indication. Does not interfere with sensitive electronic equipment. Uses one 9V battery not included. Includes one transmitter and one receiver.

Review: This Sperry Instruments CS550A Circuit Breaker Finder is awesome! - Since desertcart often mixes products, this review is on the Sperry Instruments CS550A Circuit Breaker Finder. I understand Sperry's paper conservation efforts but they really should include a little something more in the package to avoid all the 1-star reviews. While some tools calibrate automatically, you have to calibrate the CS550A manually. With the transmitter plugged into an outlet (or light socket adapter ASIN: B002DN6QX2) and the pistol grip receiver switched on and trigger firmly held in, slowly pass over the center of breakers top to bottom, left column, then right, until there's no more beeping from the receiver. This takes mostly two passes but sometimes just 1 or even 3. Then, release the trigger and slowly scan over the center of the breakers again with the trigger released. Don't be tempted to pull the trigger during the final scan! The black arrow will point to the correct breaker. A really handy feature is you can turn the breaker off and listen for absence of the transmitter beep to verify you have located the correct breaker. Using this procedure, I got NO false positives and the tool (with one exception) always identified the correct breaker. Often I had a hard time believing the tool, however, by actually turning off the identified breakers and listening for the absence of the transmitter beep to verify, I located a total of 8 mislabeled breakers out of 24! Great job electrician and shame on the city inspector. No wonder I was so confused every time I worked on something electrical! The one breaker the tool had trouble identifying was the one I was most interested in identifying. I guess I've now identified what's on it by process of elimination! This circuit has a home theater, a TV, a cable modem, a WiFi router, a VOIP box, 2 network switches, an HDHomeRun tuner, 4 Western Digital NAS drives, a Synology NAS drive, a remote start fireplace, ceiling lights, nook light, porch light, and several wall outlets with fans plugged in. The tool did identify this breaker from the nook & porch lights and from the outlets located furthest from the electronics. I'm sure it would have done better if I'd have wanted to shut down the NAS drives but then I'd hoped to avoid that by purchasing the tool. Observations: 1) The tool has trouble with heavily loaded circuits. Unplug heavy loads (fans, heaters, hairdryers, etc.) and turn off any incandescent lights that might also be on the same circuit you're testing. 2) The tool seems to remember the previous calibration setting. You have to turn it off and recalibrate each time you move the transmitter. 3) The tool seems to remember the previous calibration settings even if you just flick the power off and back on. It works best if you switch it off, go move the transmitter, switch back on, and recalibrate. 4) OK, it's cheap plastic and you have to furnish your own 9v battery but it cost just over $20 and it works great!
Review: Fines the breaker!! - While some tools calibrate automatically, you have to calibrate the CS550A manually. With the transmitter plugged into an outlet and the pistol grip receiver switched on and trigger firmly held in, slowly pass over the center of breakers top to bottom, left column, then right, until there's no more beeping from the receiver. This takes mostly two passes but sometimes just 1. Then, release the trigger and slowly scan over the center of the breakers again with the trigger released. Don't be tempted to pull the trigger during the final scan! The black arrow will point to the correct breaker. A really handy feature is you can turn the breaker off and listen for absence of the transmitter beep to verify you have located the correct breaker. Using this procedure, I got NO false positives and the tool always identified the correct breaker. Often I had a hard time believing the tool, however, by actually turning off the identified breakers and listening for the absence of the transmitter beep to verify. Observations: 1) The tool has trouble with heavily loaded circuits. Unplug heavy loads (fans, heaters, hairdryers, etc.) and turn off any incandescent lights that might also be on the same circuit you're testing. 2) The tool seems to remember the previous calibration setting. You have to turn it off and recalibrate each time you move the transmitter. 3) The tool seems to remember the previous calibration settings even if you just flick the power off and back on. It works best if you switch it off, go move the transmitter, switch back on, and recalibrate. 4) OK, it's cheap plastic and you have to furnish your own 9v battery but it cost just over $20 and it works great!

## Features

- QUICKLY AND EASILY: identifies correct circuit breaker or fuse protecting a specific electrical circuit
- SAFE FOR USE NEAR: Sensitive electronic equipment and no need to interrupt power when using
- INCLUDES: A plug style transmitter and an auto sensing receiver
- AUDIBLE ALERT AND BRIGHT LED: Visual indication on both transmitter and receiver
- DESIGNED FOR: Operation at 120V AC, 50-60Hz - UL Listed
- Receiver operates from one 9 volt battery included.Audible alert and bright LED visual indication

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B000ET403A |
| Best Sellers Rank | #108,798 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #74 in Miniature Circuit Breakers |
| Brand | SPERRY |
| Brand Name | SPERRY |
| Circuit Breaker Type | Standard |
| Current Rating | 550 Amps |
| Customer Reviews | 4.0 out of 5 stars 1,489 Reviews |
| Global Trade Identification Number | 00035632106585 |
| Included Components | Sperry Instruments CS550A Circuit Breaker Finder, Quickly Locate AC Circuits/Fuses, Visual LED, Plug Style Transmitter/Auto-Sensing Receiver, 80-140V |
| Item Dimensions D x W x H | 1.3"D x 3.4"W x 6.3"H |
| Item Type Name | Sperry Instruments CS550A Circuit Breaker Finder, Quickly Locate AC Circuits/Fuses, Visual LED, Plug Style Transmitter/Auto-Sensing Receiver, 80-140V |
| Item Weight | 3.68 ounces |
| Manufacturer | A.W. Sperry |
| Model | CS550A |
| Mounting Type | Plug-In Mount |
| Number Of Poles | 1 |
| Number of Poles | 1 |
| Product Dimensions | 1.3"D x 3.4"W x 6.3"H |
| UPC | 035632104444 035632106585 |
| Unit Count | 1.0 Count |
| Voltage | 120 Volts |
| Warranty Description | Limited One Year Warranty |

## Images

![Sperry Instruments CS550A Circuit Breaker Finder, Quickly Locate AC Circuits/Fuses, Visual LED, Plug Style Transmitter/Auto-Sensing Receiver, 120V AC, Yellow - Image 1](https://m.media-amazon.com/images/I/715YImK9VfL.jpg)

## Available Options

This product comes in different **Size** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ This Sperry Instruments CS550A Circuit Breaker Finder is awesome!
*by K***G on April 12, 2021*

Since Amazon often mixes products, this review is on the Sperry Instruments CS550A Circuit Breaker Finder. I understand Sperry's paper conservation efforts but they really should include a little something more in the package to avoid all the 1-star reviews. While some tools calibrate automatically, you have to calibrate the CS550A manually. With the transmitter plugged into an outlet (or light socket adapter ASIN: B002DN6QX2) and the pistol grip receiver switched on and trigger firmly held in, slowly pass over the center of breakers top to bottom, left column, then right, until there's no more beeping from the receiver. This takes mostly two passes but sometimes just 1 or even 3. Then, release the trigger and slowly scan over the center of the breakers again with the trigger released. Don't be tempted to pull the trigger during the final scan! The black arrow will point to the correct breaker. A really handy feature is you can turn the breaker off and listen for absence of the transmitter beep to verify you have located the correct breaker. Using this procedure, I got NO false positives and the tool (with one exception) always identified the correct breaker. Often I had a hard time believing the tool, however, by actually turning off the identified breakers and listening for the absence of the transmitter beep to verify, I located a total of 8 mislabeled breakers out of 24! Great job electrician and shame on the city inspector. No wonder I was so confused every time I worked on something electrical! The one breaker the tool had trouble identifying was the one I was most interested in identifying. I guess I've now identified what's on it by process of elimination! This circuit has a home theater, a TV, a cable modem, a WiFi router, a VOIP box, 2 network switches, an HDHomeRun tuner, 4 Western Digital NAS drives, a Synology NAS drive, a remote start fireplace, ceiling lights, nook light, porch light, and several wall outlets with fans plugged in. The tool did identify this breaker from the nook & porch lights and from the outlets located furthest from the electronics. I'm sure it would have done better if I'd have wanted to shut down the NAS drives but then I'd hoped to avoid that by purchasing the tool. Observations: 1) The tool has trouble with heavily loaded circuits. Unplug heavy loads (fans, heaters, hairdryers, etc.) and turn off any incandescent lights that might also be on the same circuit you're testing. 2) The tool seems to remember the previous calibration setting. You have to turn it off and recalibrate each time you move the transmitter. 3) The tool seems to remember the previous calibration settings even if you just flick the power off and back on. It works best if you switch it off, go move the transmitter, switch back on, and recalibrate. 4) OK, it's cheap plastic and you have to furnish your own 9v battery but it cost just over $20 and it works great!

### ⭐⭐⭐⭐⭐ Fines the breaker!!
*by E***C on March 22, 2024*

While some tools calibrate automatically, you have to calibrate the CS550A manually. With the transmitter plugged into an outlet and the pistol grip receiver switched on and trigger firmly held in, slowly pass over the center of breakers top to bottom, left column, then right, until there's no more beeping from the receiver. This takes mostly two passes but sometimes just 1. Then, release the trigger and slowly scan over the center of the breakers again with the trigger released. Don't be tempted to pull the trigger during the final scan! The black arrow will point to the correct breaker. A really handy feature is you can turn the breaker off and listen for absence of the transmitter beep to verify you have located the correct breaker. Using this procedure, I got NO false positives and the tool always identified the correct breaker. Often I had a hard time believing the tool, however, by actually turning off the identified breakers and listening for the absence of the transmitter beep to verify. Observations: 1) The tool has trouble with heavily loaded circuits. Unplug heavy loads (fans, heaters, hairdryers, etc.) and turn off any incandescent lights that might also be on the same circuit you're testing. 2) The tool seems to remember the previous calibration setting. You have to turn it off and recalibrate each time you move the transmitter. 3) The tool seems to remember the previous calibration settings even if you just flick the power off and back on. It works best if you switch it off, go move the transmitter, switch back on, and recalibrate. 4) OK, it's cheap plastic and you have to furnish your own 9v battery but it cost just over $20 and it works great!

### ⭐⭐⭐⭐ Great!!! (But read the OPERATING INSTRUCTIONS Model CS-550A CIRCUIT BREAKER FINDER)
*by L***R on November 6, 2021*

Model CS-550A CIRCUIT BREAKER FINDER I intended to write an unfavorable review because it doesn't work more than about 20 feet from the transmitter. Then I read the Amazon review by William G. Finley. Search the Internet for the "OPERATING INSTRUCTIONS Model CS-550A CIRCUIT BREAKER FINDER" PDF. Read Step 4) LOCATING A CIRCUIT BREAKER". It worked great after I followed the instructions. Four stars for neither an intuitive tool nor clear instructions. This is Step 4 from the online instructions: "4) LOCATING A CIRCUIT BREAKER (figure 3): 1. With the transmitter plugged into an AC outlet to go the circuit breaker panel and open the cover. 2. Turn on the receiver and place target on the tip firmly against the first circuit breaker in the panel. 3. Press and hold the calibration switch while moving the receiver across the circuit breakers. 4. When the receiver responds to a circuit breaker stop movement until the receiver stops responding, then continue moving the receiver to the next breaker. 5. 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. 6. After scanning all the circuit breakers in the panel release the calibration switch and rescan the circuit breakers. 7. Only one breaker will now produce a response in the receiver. 8. While continuing to hold the receiver against this breaker turn off the breaker, this will remove power to the remote transmitter and the receiver will cease producing a response. This confirms that the transmitter is no longer receiving power. 9. Turn off receiver; additionally this resets the calibration circuit if another scan is desired. 10. Always confirm that power to the outlet has been removed by noting the absence of sound and light when in the presence of the transmitter. 11. Unplug transmitter when not in use

## Frequently Bought Together

- Sperry Instruments CS550A Circuit Breaker Finder, Quickly Locate AC Circuits/Fuses, Visual LED, Plug Style Transmitter/Auto-Sensing Receiver, 120V AC, Yellow
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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-02-20*