The Klein Tools RT310 is an AFCI/GFCI outlet tester for North American 120V three-wire grounded outlets. It tests wiring conditions, simulates arc fault conditions to inspect AFCI devices, simulates ground faults to inspect GFCI devices, and detects dual-open wiring faults with simultaneous open neutral and open ground. A 10-inch flexible cord reaches difficult outlets and the unit auto-powers off after 2 minutes. Rated CAT III 135V with 6.6-foot drop protection. Includes three AAA batteries. Backed by Klein Tools' 1-year limited warranty.
How does the AFCI test actually work?
The RT310 contains a component that generates a real electrical arc — not a simulated signal. This trips compliant AFCI breakers and receptacles the same way an actual arc fault would. The device also has a thermal protection circuit that prevents the arc generator from firing when it's overheated, such as after repeated tests on a non-AFCI circuit.
The tester keeps shutting off while I'm working alone — is that normal?
Yes — the RT310 auto-powers off after 2 minutes of inactivity to conserve battery. When working between panel and outlet, pull the tester out before it shuts off, press the button to restart, then reinsert. If the 2-minute window is consistently too short, the RT390 extends auto-shutoff to 5 minutes.
Can it detect pre-existing wiring faults unrelated to AFCI or GFCI?
Yes — the RT310 reads full outlet state before and after each test. Several reviewers have discovered pre-existing open grounds and other wiring faults during what they expected to be routine AFCI/GFCI verification.
What is the flexible 10-inch cord for?
It keeps the LED display visible regardless of outlet orientation. In tight spaces, low outlets, or behind appliances, the tester body may face the wrong direction — the cord lets you position the indicator where you can see it.
Will it work on ungrounded two-prong outlets?
No — the RT310 requires a three-wire grounded 120V outlet. AFCI and GFCI protection cannot be tested on ungrounded circuits.
What's the difference between the RT310 and RT390?
RT390 adds a color LCD display (vs. LED indicators), load testing at 12/15/20A to verify circuit capacity under load, and a 5-minute auto-shutoff window. RT310 covers all the same AFCI/GFCI/dual-open tests at a lower price with an LED readout.
# Klein Tools® RT310 AFCI/GFCI Outlet Tester **Model:** `RT310` **Brand:** Klein Tools **Category:** Voltage Tester > The Klein Tools RT310 is an AFCI/GFCI outlet tester for North American 120V three-wire grounded outlets. It tests wiring conditions, simulates arc fault conditions to inspect AFCI devices, simulates ground faults to inspect GFCI devices, and detects dual-open wiring faults with simultaneous open neutral and open ground. A 10-inch flexible cord reaches difficult outlets and the unit auto-powers off after 2 minutes. Rated CAT III 135V with 6.6-foot drop protection. Includes three AAA batteries. Backed by Klein Tools' 1-year limited warranty. ## Specifications | Attribute | Value | |---|---| | Product Type | AFCI/GFCI Outlet Tester | | Voltage Range Ac | 120V AC | | Cat Rating | CAT III 135V | | Tests Gfci | Yes | | Tests Afci | Yes | | Detects Dual Open Fault | Yes | | Outlet Types Tested | 3-wire grounded 120V AC | | Cord Length In | 10 | | Auto Poweroff Min | 2 | | Display Type | LED | | Battery Type | 3 × AAA | | Battery Required | Yes | | Drop Protection Ft | 6.6 | | Overall Length In | 7.4 | | Assembled Weight Oz | 8.5 | | Barcode (UPC) | 092644691829 | | Warranty | 1-year limited | ## What's Included - Outlet tester - 3 × 1.5V AAA alkaline batteries Source: https://www.jaspecs.com/klein-tools/voltage-tester/rt310-klein-tools-afci-gfci-outlet-tester/