Extech CB10 Circuit Breaker Finder and Receptacle Tester Instruction Manual

1. Introduction

The Extech CB10 is an AC Circuit Breaker Finder and Receptacle Tester designed to assist in electrical diagnostics. This device efficiently locates 110 Volt to 125-Volt AC circuit breakers and fuses, and verifies receptacle wiring. It provides both audible and visual indications for circuit identification and features a variable sensitivity adjustment for precise operation. Additionally, the CB10 can test GFCI (Ground Fault Circuit Interrupter) circuits to ensure proper functionality.

Image 1.1: The Extech CB10, highlighting its functions as a 3-in-1 tester for circuit breaking, circuit testing, and GFCI receptacle testing.

2. What's in the Box

Upon unpacking, please verify that all components are present:

• CB10 Receiver Unit
• GFCI Transmitter Unit
• One 9V Battery (for the Receiver)

Image 2.1: Contents of the Extech CB10 package, including the receiver, GFCI transmitter, and a 9V battery. Product dimensions are 6.4 x 2.2 x 1.5 inches, and weight is 4 oz.

3. Safety Information

Always observe safety precautions when working with electrical circuits. This device is designed for 110V to 125V AC circuits. Do not attempt to use it on circuits outside this voltage range. Ensure the device is in good working condition before use. If the device appears damaged, do not use it.

4. Getting Started

4.1 Battery Installation (Receiver)

1. Locate the battery compartment on the back of the CB10 Receiver unit.
2. Open the battery compartment cover.
3. Connect the 9V battery to the battery clip, observing correct polarity.
4. Place the battery into the compartment and close the cover securely.

5. Operating Instructions

5.1 Locating Circuit Breakers

1. Plug the GFCI Transmitter unit into the electrical outlet that is connected to the circuit you wish to identify. Ensure the outlet is live.
2. Go to the electrical service panel (breaker box).
3. Turn on the Receiver unit.
4. Adjust the sensitivity dial on the Receiver to a medium or high setting initially.
5. Slowly slide the tip of the Receiver along the circuit breakers in the panel.
6. The Receiver will emit an audible tone and/or visual indication (LEDs) when it detects the signal from the correct circuit breaker.
7. To pinpoint the exact breaker, gradually reduce the sensitivity of the Receiver as you pass it over the breakers. The correct breaker will produce the strongest and most consistent signal at the lowest sensitivity setting.

Image 5.1: The GFCI Transmitter is plugged into an outlet, sending a signal. The Receiver is then used to scan the circuit breaker panel to identify the corresponding breaker.

5.2 Receptacle Wiring Testing

The GFCI Transmitter also functions as a receptacle tester to check for common wiring faults.

1. Plug the GFCI Transmitter into the receptacle you wish to test.
2. Observe the combination of red and green LEDs on the front of the transmitter. These LEDs indicate the wiring status.
3. Refer to the legend on the transmitter or the table below for interpretation of the LED patterns.

Image 5.2: The GFCI Transmitter displaying LED combinations that indicate correct wiring or various fault conditions.

5.3 GFCI Circuit Testing

To test the functionality of a GFCI protected receptacle:

1. Plug the GFCI Transmitter into the GFCI receptacle.
2. Verify that the wiring is correct by observing the LED indicators (refer to Section 5.2).
3. Press the red GFCI test button on the transmitter.
4. A working GFCI receptacle should trip, cutting power to the outlet. The LEDs on the transmitter will turn off.
5. If the GFCI does not trip, it may be faulty and should be inspected by a qualified electrician.
6. To restore power, press the reset button on the GFCI receptacle.

Image 5.3: The GFCI Transmitter plugged into an outlet, showing bright red and green LEDs for wiring status and indicating audible and visual circuit breaker indication.

6. Understanding Indicators

6.1 GFCI Transmitter LED Indications

The GFCI Transmitter uses a combination of red and green LEDs to indicate wiring conditions:

6.2 Receiver Indications

The Receiver provides both audible and visual feedback:

• Audible Tone: A distinct beeping sound indicates the presence of the signal from the transmitter. The tone may become more rapid or change in pitch as you approach the correct breaker.
• Visual LED: A red LED on the receiver will illuminate when a signal is detected.

7. Sensitivity Adjustment

The Receiver features a variable sensitivity dial (OFF/Lo/Hi) to help pinpoint the correct circuit breaker. This adjustment is crucial for accurate identification, especially in crowded breaker panels or when signals might bleed between adjacent breakers.

• Hi (High Sensitivity): Use this setting for initial scanning to quickly identify the general area of the circuit breaker.
• Lo (Low Sensitivity): Once the general area is found, switch to a lower sensitivity setting. This allows for more precise identification, as the signal will only be strong enough to trigger the receiver when directly over the correct breaker.
• OFF: Turns the receiver off.

Image 7.1: The Receiver unit, showing the variable sensitivity adjustment dial for pinpointing the correct circuit breaker.

8. Maintenance

• Cleaning: Wipe the device with a dry, soft cloth. Do not use abrasive cleaners or solvents.
• Battery Replacement: Replace the 9V battery in the Receiver when the indicator light dims or the device fails to operate correctly. Remove the battery if the device will not be used for an extended period to prevent leakage.
• Storage: Store the CB10 in a cool, dry place, away from direct sunlight and extreme temperatures.

9. Troubleshooting

9.1 Receiver Not Detecting Signal

• Check Transmitter: Ensure the GFCI Transmitter is securely plugged into a live outlet.
• Check Receiver Battery: Verify the 9V battery in the Receiver is fresh and correctly installed.
• Adjust Sensitivity: Start with the Receiver's sensitivity set to 'Hi' to ensure a broad detection range.
• Signal Interference: In some cases, other electrical devices or wiring configurations can cause interference. Try adjusting sensitivity or moving the receiver slowly.

9.2 Inaccurate Breaker Identification

• Reduce Sensitivity: Once a general area is identified, gradually lower the sensitivity of the Receiver. This helps to isolate the signal to the specific breaker.
• Slow Scan: Move the Receiver slowly and deliberately over each breaker.
• Multiple Signals: If multiple breakers seem to respond, it might indicate a shared neutral or other complex wiring. Use the lowest sensitivity to find the strongest, most consistent signal.

9.3 GFCI Transmitter LEDs Not Lighting Up

• No Power: The outlet may not have power. Check the circuit breaker for that outlet.
• Faulty Outlet: The outlet itself may be faulty.

10. Specifications

11. Warranty

The Extech CB10 comes with a one-year warranty from the date of purchase. This warranty covers defects in materials and workmanship under normal use. It does not cover damage resulting from misuse, unauthorized modification, accident, or neglect. For warranty service or technical support, please contact Extech customer service.