---
product_id: 509901809
title: "Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time"
brand: "klein tools"
price: "€ 323.06"
currency: EUR
in_stock: true
category: "Klein Tools"
url: https://www.desertcart.be/products/509901809-klein-tools-rt390-circuit-analyzer-with-large-lcd-identifies-wiring
store_origin: BE
region: Belgium
---

# Load testing at 12A, 15A, 20A Large color LCD for clear results Dual wiring fault detection & AFCI/GFCI testing Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time

**Brand:** klein tools
**Price:** € 323.06
**Availability:** ✅ In Stock

## Summary

> ⚡ Power Up Your Precision: The Ultimate Circuit Analyzer for Pros Who Demand More

## Quick Answers

- **What is this?** Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time by klein tools
- **How much does it cost?** € 323.06 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.be](https://www.desertcart.be/products/509901809-klein-tools-rt390-circuit-analyzer-with-large-lcd-identifies-wiring)

## Best For

- klein tools enthusiasts

## Why This Product

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

## Key Features

- • **Dual Fault Detection:** Identify open neutral and open ground faults for unmatched safety assurance.
- • **Powerful Load Testing:** Test voltage drops under 12A, 15A, and 20A loads to ensure peak electrical performance.
- • **Effortless Portability:** Detachable cord and auto power-off keep your workflow smooth and battery life long.
- • **See Faults in Full Color:** Large, vibrant LCD display makes wiring faults instantly clear—no guesswork.
- • **Smart AFCI & GFCI Inspection:** Measure trip time and current to verify critical device functionality with precision.

## Overview

The Klein Tools RT390 Circuit Analyzer is a professional-grade tester designed for North American 120V AC outlets. Featuring a large color LCD, it detects wiring faults including dual faults, inspects AFCI and GFCI devices by measuring trip times, and performs load testing at 12A, 15A, and 20A to assess voltage drops. Compact and battery-powered with a detachable cord and auto power-off, it delivers reliable, easy-to-interpret diagnostics trusted by electricians since 1857.

## Description

The Klein Tools RT390 is a Circuit Analyzer that tests the wiring conditions at an electrical outlet, displays AC line voltage, inspects AFCI and GFCI devices with time to trip device, and performs voltage drop tests at 12A, 15A and 20A current loads. Results are easy to understand with large, color LCD. The tester is designed for use with North American 120V AC 3-wire electrical outlets. For more than 160 years, Klein Tools has manufactured premium-quality, professional-grade hand tools that deliver the performance, durability and precision needed to get the job done right. Our family of engineers, workers and craftsman continue to put six generations of expertise into every tool we create by using only the highest quality materials, superior workmanship, and keeping manufacturing as close to home as we can. Klein isn't just the name of our company, it's also our family name. And since we're an American company that's family-owned and family-run, you know you can count on us to be here tomorrow. Klein Tools doesn't just make great products, we make great products that stand up to the demands of the professionals who use them every day ... Since 1857.

## Features

- CLEAR COLOR LCD DISPLAY: Circuit Analyzer with large color LCD provides easy-to-understand results for wiring faults, AFCI, GFCI, voltage drops, and device trip time
- COMPREHENSIVE WIRING FAULT DETECTION: Detect and identify common wiring faults in standard, AFCI, and GFCI electrical outlets, ensuring thorough evaluation
- DUAL WIRING FAULT DETECTION: Capable of detecting dual wiring faults, including open neutral and open ground, enhancing safety measures
- AFCI AND GFCI DEVICE INSPECTION: Inspect AFCI and GFCI devices, measuring trip time and trip current for accurate functionality assessment
- LOAD TESTING CAPABILITIES: Conduct 12A, 15A, and 20A load testing to measure percentage voltage drops, providing valuable insights into electrical performance
- AUTO POWER OFF: Automatically powers off after 5 minutes of inactivity, conserving battery life and ensuring long-term usage
- DETACHABLE CORD: Detachable cord allows for easy storage, providing convenience and organized handling of the Circuit Analyzer
- For use with North American 120V AC 3-wire electrical outlets
- Safety Rating: CAT III 135V

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0BT87LJRL |
| Best Sellers Rank | #26,687 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #48 in Circuit Testers |
| Brand Name | KLEIN TOOLS |
| Color | Orange |
| Customer Reviews | 4.8 4.8 out of 5 stars (282) |
| Global Trade Identification Number | 00092644693632 |
| Included Components | 3 x AAA Batteries, Instructions, and Pouch |
| Item Dimensions | 7.07 x 2.72 x 1.51 inches |
| Item Type Name | Building Material |
| Item Weight | 0.49 Pounds |
| Manufacturer | Klein Tools |
| Measurement Type | Voltmeter, Ammeter, Ohmmeter, Time-based |
| Minimum Operating Voltage | 135 Volts (AC) |
| Model | RT390 |
| Part Number | RT390 |
| Power Source | Battery Powered |
| Specification Met | Cat Iii 135v, Afci, Gfci, Ul, Fcc |
| Style Name | Receptacle Tester w/Load Test |
| UPC | 092644693632 |
| Unit Count | 1.0 Count |
| Upper Temperature Rating | 55 Degrees Celsius |
| Warranty Description | Call vendor for warranty |

## Product Details

- **Brand:** KLEIN TOOLS
- **Color:** Orange
- **Item Weight:** 0.49 Pounds
- **Power Source:** Battery Powered
- **Style:** Receptacle Tester w/Load Test

## Images

![Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time - Image 1](https://m.media-amazon.com/images/I/51n2Tv4OxkL.jpg)

## Questions & Answers

**Q: does this actually place a load on the circuit for for voltage drop?**
A: It simulates a 12,15, and 20 amp load and displays the percentage drop, according to the operating instructions.

**Q: Will this indicate open neutral or open ground when circuit is not energized?**
A: Way late on answer this.
If you’re talking about (Klein Tools RT210 Outlet Tester) then no, it has to have power on the circuit as this is not battery powered to show the tester how it’s wired.

**Q: Does this simulate and test both serial and parallel arc fault conditions?**
A: This tester plugs into an outlet on the circuit under test, so it seems to me that automatically makes it a parallel device. Therefore it can only simulate an arc fault such as might occur in a parallel device, i.e. what you normally plug into an outlet. (A typical faulty item being be a lamp with a frayed power cord.) I believe the tester would have to be wired into the circuit in series to simulate a serial arc fault. I don't know the nature of the tester's design but it may be that tripping an AFCI unit (an AFCI outlet, for instance) with a parallel fault simulation may also prove the AFCI's ability to respond to a serial arc fault, at least in part. Disclaimer: I'm not an electrician or EE so you may want to dig farther on this subject, but I believe I have the basics right.

**Q: Does this protect trip a gfci protected receptacle with an open ground?**
A: No it will not. No tester will trip a GFCI with open ground. You have to use the button on the receptacle/breaker in that case. Make sure the outlet is labeled with "no equipment ground."

## Frequently Bought Together

- Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time
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*Product available on Desertcart Belgium*
*Store origin: BE*
*Last updated: 2026-07-12*