Klein Tools RT390 Circuit Analyzer

Product Overview

The Klein Tools RT390 is a circuit analyzer designed to test the wiring condition of North American 120V AC 3-wire electrical outlets. It features:

• Inspection and checking of AFCI (Arc Fault Circuit Interrupter) and GFCI (Ground Fault Circuit Interrupter) devices.
• Detection and identification of common wiring faults.
• Display of AC line voltage.
• 12A, 15A, and 20A load testing to measure percentage voltage drop.

The tester has a 2-meter cord and an IP40 ingress protection rating.

General Specifications

The Klein Tools RT390 circuit analyzer tests wiring conditions, displays AC line voltage, inspects GFCI and AFCI devices (including trip time), and performs voltage drop tests at 12A, 15A, and 20A loads. It is designed for North American 120V AC 3-wire outlets.

• Environment: Indoor. Do NOT expose to moisture, rain, or snow.
• Operating Altitude: Up to 6562 ft. (2000m)
• Relative Humidity: Less than 85% non-condensing
• Operating Temperature: 32°F to 122°F (0°C to 50°C)
• Storage Temperature: -4°F to 140°F (-20°C to 60°C)
• Dimensions: 7.1" x 2.7" x 1.5" (17.93 cm x 6.93 cm x 3.86 cm)
• Cord: 14AWG, 15A, 12" (30.5cm) NEMA 5-15P to IEC 320 C13
• Weight: 10.92 oz. (311.1 g) including batteries
• Battery Type: 3 x 1.5V AAA Alkaline
• Standards: Conforms to UL STD.61010-1, 61010-2-030, 1436. Certified to CSA STD C22.2 # 61010-1, 61010-2-030, 160.
• Pollution Degree: 2
• Drop Protection: 6.6 ft. (2m)
• Ingress Protection: IP40 dust resistant
• Safety Rating: CAT III 135V. Measurement category III applies to test and measuring circuits connected to the distribution part of a building's low-voltage MAINS installation.

Specifications are subject to change.

Electrical Specifications

Warnings

To ensure safe operation and service of the tester, follow these instructions. Failure to observe these warnings can result in severe injury or death.

• The RT390 is designed for use with North American 3-wire grounded 120V electrical outlets. DO NOT connect to higher voltage electrical supplies.
• Only use the tester with the supplied NEMA-rated cord.
• Prior to use, always verify tester operation by testing on a known live and correctly wired electrical outlet.
• DO NOT attempt an AFCI testing event on a circuit with powered ON equipment or devices. Remove or power OFF prior to testing.
• DO NOT use if the tester appears damaged in any way.
• The tester is intended for indoor use only.
• To reduce the possibility of erroneous readings:
  • All appliances or equipment on the circuit being tested should be disconnected.
  • Turn off or move away from equipment that causes electromagnetic interference.
• DO NOT attempt AFCI, GFCI, 30mA ground fault testing, or load testing on an incorrectly wired outlet. Consult a qualified electrician to resolve wiring problems.
• This tester only detects common wiring problems. ALWAYS consult a qualified electrician to resolve wiring problems. The device:
  • Will not indicate quality of ground.
  • Will not indicate two hot wires in a circuit.
  • Will not detect a combination of multiple wiring faults.
  • Will not indicate reversed ground and neutral.
• AFCI indicators produce characteristics that mimic some forms of arcing. Because of this, the indicator may give a false indication that the AFCI is not functioning properly. If this occurs, recheck the operation of the AFCI.

Symbols on Tester

Risk of danger. Important information: It is important that users of this tester read, understand, and follow all warnings, cautions, safety information, and instructions in this manual before operating or servicing this tester. Failure to follow instructions could result in death or serious injury.

Risk of electric shock.

i Read instructions.

Tester Feature Details

NOTE: There are no user-serviceable parts inside the tester.

Front of Tester:

• 1. Power/Reset Button: Used to power the tester ON/OFF.
• 2. LCD Screen: Displays test results, wiring conditions, and messages.
• 3. "ENERGIZED" Indicator: Illuminates when voltage is detected.
• 4. GFCI Test Button: Initiates a GFCI test.
• 5. AFCI Test Button: Initiates an AFCI test.
• 6. 30mA Ground Fault Test Button: Initiates a 30mA ground fault test.
• 7. Load Test Button: Initiates a load test to measure voltage drop.
• 8. Battery Cover: Provides access to the battery compartment.

Top of Tester:

• 9. Plug Connector: Connects to the electrical outlet.
• 10. NEMA Rated Cord: The power cord for the tester.

LCD Feature Details

The LCD screen displays various indicators and messages:

• A. Auto-Power Off Indicator: Shows when the auto-power off feature is active.
• B. Circuit Energized Indicator: Appears at the top of the LCD when voltage is detected.
• C. Battery Life Indicator: Turns red when batteries need replacement.
• D. AC Line Voltage: Displays the measured AC voltage.
• E. Wiring Condition: Shows the detected wiring status (e.g., "CORRECT WIRING", "OPEN GROUND").
• F. Test Performed: Indicates that a test has been completed.
• G. Trip Time: Displays the time it took for a GFCI or AFCI device to trip.
• H. Trip Current: Displays the current that caused a GFCI or AFCI device to trip.
• I. Voltage Drop: Shows the percentage of voltage drop during a load test.
• J. Allow Unit to Cool Down Message: Appears when the tester needs to cool down between tests.
• K. Circuit Not Energized Indicator: Appears when no voltage is detected.
• L. HOLD Indicator: Displays when the tester is holding the last reading for 10 seconds after being removed from an outlet.
• M. Trip Failure Message: Indicates a failure in the GFCI or AFCI trip test.
• N. Disabled Due To Improper Wiring Message: Appears when test buttons are deactivated due to incorrect wiring.

The LCD can display specific wiring conditions like "CORRECT WIRING", "OPEN GROUND", "HOT & GRD REVERSED", "OPEN NEUTRAL", "OPEN GROUND OPEN NEUTRAL", "HOT & NEU REVERSED", and "OPEN HOT". It also shows LINE VOLTAGE, NO VOLTAGE, or >30V VOLTAGE. If detected voltage is low (30-85V AC) or high (135-150V AC), the voltage display may change from white to red, even if "CORRECT WIRING" is indicated.

Operating Instructions

The RT390 is designed for North American 120V AC 3-wire grounded electrical outlets. Do not connect to higher voltage supplies. Always verify tester operation on a known live and correctly wired outlet before use.

Power ON/OFF

Press and hold the Power/Reset button (1) for two seconds to power the tester ON or OFF. When powered ON and not connected to a circuit, the LCD will display "000" and "Open Hot". The tester automatically powers OFF after 5 minutes of inactivity to conserve battery life, unless it is plugged into an energized circuit.

Wiring Condition

With the tester powered ON and inserted into an outlet, the "ENERGIZED" Indicator (3) illuminates, and the Circuit Energized Indicator (B) appears on the LCD if voltage is detected. The tester displays the wiring condition (E) and line voltage (D). If removed from the outlet, the tester holds the information on the LCD for 10 seconds, displaying the Hold Indicator (L), and the Wiring Condition Indicator (E) blinks. The LCD resets when plugged into another circuit or if no voltage is detected.

If the tester indicates an incorrect wiring condition, consult a qualified electrician. The tester does not indicate ground quality, multiple hot wires, reversed neutral/ground conductors, or combined defects.

To reduce the possibility of erroneous readings, disconnect all appliances/equipment on the circuit and move away from equipment causing electromagnetic interference.

Wiring Diagram Representation:

*Expected voltage reading on LCD based on the indicated wiring condition. If detected voltage is low (30-85V AC) or high (135-150V AC), the voltage display may change from white to red, even if "CORRECT WIRING" is indicated.

GFCI, AFCI, and 30mA Ground Fault Functions

Refer to the respective device user manuals for installation and operation. Power on the tester and plug into the outlet. The wiring condition should indicate "CORRECT WIRING", the "ENERGIZED" Indicator (3) should be illuminated, and the Circuit Energized Indicator (B) should appear on the LCD.

If the outlet is not wired correctly, DO NOT attempt testing; consult a qualified electrician.

• Press the GFCI button (4) to create a 6mA to 9mA ground fault to trip the GFCI device.
• Press the AFCI button (5) to simulate a parallel arc condition to trip the AFCI device.
• Press the 30mA Ground Fault Test button (6) to create a 30mA ground fault to trip a 30mA GFCI device. (Note: 30mA ground fault protection is not standard in all GFCI circuit breakers.)

If the Circuit Not Energized Indicator (K) is displayed and the "ENERGIZED" Indicator (3) is off, reset the device being tested. After reset, the wiring condition should show "CORRECT WIRING", and the "ENERGIZED" Indicator (3) and Circuit Energized Indicator (B) should be illuminated.

If the circuit remains energized or shows other conditions, the device may be miswired, improperly installed, or malfunctioning. Consult a qualified electrician.

Notes:

• The GFCI (4), AFCI (5), and 30mA (6) buttons are deactivated if wiring is incorrect; an error message (N) will appear on the LCD.
• Allow 20 seconds between successive AFCI testing events.
• An error message may appear indicating the tester needs to cool down (J) during AFCI testing. A subsequent test cannot be initiated until the unit cools down.
• Some AFCI devices may not trip if the cable run from the test location to the breaker exceeds 100 ft. (30.48 m).
• If an AFCI test fails to trip, the RT390 performs a background Load Test to check for high line impedance. An error message (M) may appear.

Test Load Function

Plug the tester into the outlet and ensure the wiring condition (E) shows "CORRECT WIRING" and the "ENERGIZED" Indicator (3) and Circuit Energized Indicator (B) are illuminated.

If the outlet is not wired correctly, DO NOT attempt testing; consult a qualified electrician.

Press the Load Test button (7). The 12A, 15A, and 20A test load voltage and percentage voltage drop will be displayed. If the voltage drop exceeds 5%, the background color changes to red.

Notes:

• The Load Test button (7) is deactivated if the outlet is not wired correctly.
• During a Load test, a "cool down" message (J) may appear. A successive Load test cannot be initiated until the unit cools down.

Battery Replacement

When the Battery Life Indicator (C) turns red, replace the batteries.

1. Loosen the screw on the battery cover (8).
2. Replace the 3 x AAA batteries, observing proper polarity.
3. Replace the battery door and fasten securely with the screw.

Safety: To avoid risk of electric shock, unplug from any voltage source before removing the battery door. Do not operate the tester while the battery door is removed.

Cleaning

Ensure the tester is turned off. Wipe with a clean, dry, lint-free cloth. Do not use abrasive cleaners or solvents.

Storage

Remove batteries if the tester will not be used for a prolonged period. Do not expose to high temperatures or humidity. After storage in extreme conditions, allow the tester to return to normal operating conditions before use.

Warranty

Information regarding warranty is not detailed in the provided text.

Disposal / Recycle

Do not place equipment and accessories in the trash. Dispose of items properly according to local regulations. For additional information, please see www.epa.gov/recycle.

Customer Service

For customer service, contact:

• Phone: 1.888.610.7664
• Website: www.calcert.com
• Email: sales@calcert.com