--- product_id: 513814177 title: "Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time, Orange" brand: "klein tools" price: "€ 442.94" currency: EUR in_stock: true reviews_count: 5 category: "Klein Tools" url: https://www.desertcart.at/products/513814177-klein-tools-rt390-circuit-analyzer-with-large-lcd-identifies-wiring store_origin: AT region: Austria --- # Measures voltage drop at 12A, 15A, 20A loads Large color LCD for clear results Displays AFCI/GFCI trip time & current Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time, Orange **Brand:** klein tools **Price:** € 442.94 **Availability:** ✅ In Stock ## Summary > ⚡ Power Up Your Precision – Test Smarter, Work Safer! ## 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, Orange by klein tools - **How much does it cost?** € 442.94 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.at](https://www.desertcart.at/products/513814177-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 - • **Advanced AFCI & GFCI Testing:** Measure trip time and current to ensure your outlets meet the highest safety standards. - • **Comprehensive Wiring Fault Detection:** Identify open neutral, open ground, and other common wiring issues effortlessly. - • **Instant Clarity with Large Color LCD:** See wiring faults and test results at a glance—no guesswork, just precision. - • **Trusted Professional Grade Since 1857:** Crafted by Klein Tools, a family-owned brand synonymous with durability and accuracy. - • **Voltage Drop Testing at Multiple Loads:** Test under 12A, 15A, and 20A loads to guarantee optimal circuit performance. ## 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 identifies common wiring faults, inspects AFCI and GFCI devices with trip time and current display, and measures voltage drop under multiple load conditions. Lightweight and battery-powered, it delivers trusted accuracy and durability from a family-owned brand with over 160 years of expertise. ## 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. Review: One has the option of a number of GFCI testers of which the Klein RT 310 and 350, the Fluke Pro 120+ are generally the best. But there's a new king in town. The RT390 is expensive and bulky, but it absolutely demands to be in the kit of any home inspector, safety inspector, electrician, or any homeowner who plans to do more than incidental work on their electrical systems. First, the arrival of AFCI's and especially hybrid AFCI/GFCI's has changed the outlet tester game. These breakers, Arc Fault Circuit Interruptors, detect arcs in the wiring and are most effective in identifying and protecting against electrical fires (GFCI's protect more directly against shocks emanating from the outlet and attached products). Most outlet testers don't test AFCI's. The Klein RT250 is a basic GFCI tester. Bump up to a RT310 and you get AFCI testing as well, but there's no diagnostic capability in the 310 -- it's a simple go/no-go tester that can't tell you anything about what's wrong. The RT350 does a bit more, but doesn't generate enough data for you to figure out what's wrong or how to fix it. I wouldn't generally recommend the 350 now that the 390 is available. The RT390 offers a number of significant advantages: First, it tests any outlet for both arc and ground fault integrity. Second, it tests at multiple trip levels so you can predict whether you just have a tired or non-exercised interruptor. Testing it side by side with a 350, the 390 was notably more consistent and accurate than the 350, in particular with regards to false negatives (the 390 identified arc faults in four times more installations than the 350. And lastly, the 390 is much more rugged in the case design, the cable connector, and the sturdiness of the internal circuit boards and components. What is missing in the 390? I'd love to see a set of clip leads so I could test an outlet box at the bare wires before installing the receptacle, And at nearly $200 a hard foam case would be appreciated. However, these are nits. This can be the most significant risk-prevention tool in your toolbox and should replace non-contact sniffers and the cheaper GFCI testers that we all carry around and rely on. Five stars from me. Review: Lo único vamos del producto es que las baterías se dañan muy rápido, hablo que una semana después de ponerlas se vaciaron :( así que recomiendo quitarlas cada que no lo usen o ponerle desde el principio unas de buena calidad ## Features - LARGE COLOR LCD: Easy to understand results displayed on a large LCD - DETECT COMMON WIRING FAULTS: Identify common wiring faults, including open neutral/open group - INSPECT AFCI AND GFCI DEVICES: Along with time to trip and trip current in electrical outlets - MEASURE PERCENT VOLTAGE DROP: 12A, 15A, and 20A load testing to measure percentage voltage drops - International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0BT87LJRL | | Brand | KLEIN TOOLS | | Colour | Orange | | Customer Reviews | 4.8 4.8 out of 5 stars (258) | | Global Trade Identification Number | 00092644693632 | | Included Components | 3 x AAA Batteries, Instructions, and Pouch | | Item Dimensions | 18 x 6.9 x 3.8 centimetres | | Item Type Name | Circuit Analyzer | | Item Weight | 222 g | | Manufacturer | Klein Tools | | Maximum Operating Voltage | 120 Volts | | Measurement Type | Voltmeter, Ammeter, Ohmmeter, Time-based | | Minimum Operating Voltage | 135 Volts (AC) | | Model Number | RT390 | | Power Source | Battery Powered | | Specification Met | Cat Iii 135v, Afci, Gfci, Ul, Fcc | | Style Name | Receptacle Tester w/Voltage Drop | | UPC | 092644693632 | | Unit Count | 1.0 count | | Upper Temperature Rating | 55 Degrees Celsius | ## Product Details - **Brand:** KLEIN TOOLS - **Colour:** Orange - **Item weight:** 222 g - **Power source:** Battery Powered - **Style:** Receptacle Tester w/Voltage Drop ## Images ![Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time, Orange - Image 1](https://m.media-amazon.com/images/I/51n2Tv4OxkL.jpg) ![Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time, Orange - Image 2](https://m.media-amazon.com/images/I/61dL1IUkdTL.jpg) ![Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time, Orange - Image 3](https://m.media-amazon.com/images/I/614yoSvuN-L.jpg) ![Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time, Orange - Image 4](https://m.media-amazon.com/images/I/71FxkqNd7pL.jpg) ![Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time, Orange - Image 5](https://m.media-amazon.com/images/I/61UorKMK6zL.jpg) ## Available Options This product comes in different **Style** options. ## 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." ## Customer Reviews ### ⭐⭐⭐⭐⭐ Review *by M***T on 6 January 2026* One has the option of a number of GFCI testers of which the Klein RT 310 and 350, the Fluke Pro 120+ are generally the best. But there's a new king in town. The RT390 is expensive and bulky, but it absolutely demands to be in the kit of any home inspector, safety inspector, electrician, or any homeowner who plans to do more than incidental work on their electrical systems. First, the arrival of AFCI's and especially hybrid AFCI/GFCI's has changed the outlet tester game. These breakers, Arc Fault Circuit Interruptors, detect arcs in the wiring and are most effective in identifying and protecting against electrical fires (GFCI's protect more directly against shocks emanating from the outlet and attached products). Most outlet testers don't test AFCI's. The Klein RT250 is a basic GFCI tester. Bump up to a RT310 and you get AFCI testing as well, but there's no diagnostic capability in the 310 -- it's a simple go/no-go tester that can't tell you anything about what's wrong. The RT350 does a bit more, but doesn't generate enough data for you to figure out what's wrong or how to fix it. I wouldn't generally recommend the 350 now that the 390 is available. The RT390 offers a number of significant advantages: First, it tests any outlet for both arc and ground fault integrity. Second, it tests at multiple trip levels so you can predict whether you just have a tired or non-exercised interruptor. Testing it side by side with a 350, the 390 was notably more consistent and accurate than the 350, in particular with regards to false negatives (the 390 identified arc faults in four times more installations than the 350. And lastly, the 390 is much more rugged in the case design, the cable connector, and the sturdiness of the internal circuit boards and components. What is missing in the 390? I'd love to see a set of clip leads so I could test an outlet box at the bare wires before installing the receptacle, And at nearly $200 a hard foam case would be appreciated. However, these are nits. This can be the most significant risk-prevention tool in your toolbox and should replace non-contact sniffers and the cheaper GFCI testers that we all carry around and rely on. Five stars from me. ### ⭐⭐⭐ Review *by E***A on 4 August 2024* Lo único vamos del producto es que las baterías se dañan muy rápido, hablo que una semana después de ponerlas se vaciaron :( así que recomiendo quitarlas cada que no lo usen o ponerle desde el principio unas de buena calidad ### ⭐⭐⭐⭐ Review *by L***Y on 30 December 2024* Works well. Expensive for what it does. If I ever need to replace it.... I would look for a cheaper option. ## Frequently Bought Together - Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time - Klein Tools 69411 Circuit Breaker Finder Accessory Kit, Circuit Breaker Leads, Circuit Breaker Adapters --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.at/products/513814177-klein-tools-rt390-circuit-analyzer-with-large-lcd-identifies-wiring](https://www.desertcart.at/products/513814177-klein-tools-rt390-circuit-analyzer-with-large-lcd-identifies-wiring) --- *Product available on Desertcart Austria* *Store origin: AT* *Last updated: 2026-04-22*