---
product_id: 748753355
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: "HK$318051"
currency: HKD
in_stock: false
reviews_count: 5
category: "Klein Tools"
url: https://www.desertcart.hk/products/748753355-klein-tools-rt390-circuit-analyzer-with-large-lcd-identifies-wiring
store_origin: HK
region: Hong Kong
---

# Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time

**Brand:** klein tools
**Price:** HK$318051
**Availability:** ❌ Out of Stock

## 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?** HK$318051 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.hk](https://www.desertcart.hk/products/748753355-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

## Description

desertcart.co.jp: Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time : Industrial & Scientific

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

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN  | B0BT87LJRL |
| Batteries  | 4 12V batteries required. (included) |
| Customer Reviews | 4.7 4.7 out of 5 stars (229) |
| Date First Available  | March 20, 2023 |
| Item model number  | RT390 |
| Product Dimensions  | 17.96 x 6.91 x 3.84 cm; 222.26 g |

## 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/41+ow4W+XSL.jpg)
![Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time - Image 2](https://m.media-amazon.com/images/I/41BMv5uopGL.jpg)
![Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time - Image 3](https://m.media-amazon.com/images/I/41DfuCzpHVL.jpg)
![Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time - Image 4](https://m.media-amazon.com/images/I/41d6ulusSFL.jpg)
![Klein Tools RT390 Circuit Analyzer with Large LCD, Identifies Wiring Faults, GFCI and AFCI Tester, Voltage Drop, Displays Trip Time - Image 5](https://m.media-amazon.com/images/I/51HpLwedTVL.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."

## Customer Reviews

### ⭐⭐⭐⭐⭐ Review
*by M***T on January 6, 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 August 4, 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 December 30, 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

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*Product available on Desertcart Hong Kong*
*Store origin: HK*
*Last updated: 2026-03-03*