Klein Tools ET310 Digital Circuit Breaker Finder and Integrated GFCI Voltage Tester

Product Overview

The Klein Tools ET310 Digital Circuit Breaker Finder and Integrated GFCI Voltage Tester is a compact handheld device that assists electricians, contractors, and maintenance personnel in identifying circuit breakers and verifying GFCI voltage presence. Designed for field use, the tool offers a dual function that merges breaker locating technology with a voltage tester that can detect GFCI operation at the point of use.

Key Features

• Digital Circuit Breaker Finder – Uses a sensor to detect the magnetic field of an energized circuit breaker, providing an audible or visual cue to the user.
• Integrated GFCI Voltage Tester – Allows quick assessment of voltage presence and GFCI status directly from the same device.
• Handheld Design – Sized for easy handling in tight spaces, facilitating work near walls, panels, or conduit.
• Clear Readouts – Displays information on the device’s screen to indicate breaker location and voltage status.
• Built for Professionals – Meets the needs of electricians and maintenance teams who require reliable breaker identification and voltage testing in a single tool.

Applications

The ET310 is suited for tasks that involve locating the breaker that powers a specific outlet, light fixture, or appliance. By sending a probe from a known circuit, the user can quickly find the corresponding breaker without guessing or opening panels. The integrated GFCI voltage tester enables on‑site verification that a circuit breaker is properly protecting a GFCI outlet or that the outlet is correctly receiving voltage. These functions support troubleshooting, code compliance checks, and routine maintenance.

How It Works

When the user activates the breaker finder function, a probe placed near a suspected breaker emits a signal that the device receives through its sensor. The sensor’s response is interpreted and shown on the display, indicating whether the targeted breaker is on. For voltage testing, the user connects the tester’s contacts to the outlet or device in question. The device measures the voltage present and indicates whether a GFCI is functioning. Because both functions are integrated, the tool reduces the number of separate instruments required on a job site.

Design and Construction

Constructed from durable materials suitable for repeated field use, the ET310 balances robustness with a lightweight form factor. The housing protects internal components from impacts and environmental exposure common to construction sites. An ergonomic grip ensures the device remains secure during operation. The screen is positioned for clear visibility in various lighting conditions, aiding accurate reading of results.

Installation and Calibration

Setup requires no external power; the device operates with built‑in batteries that support the functions during a typical work shift. Calibration is performed automatically upon startup, allowing the user to rely on the tool for accurate readings without manual adjustment. This straightforward operation streamlines workflows and keeps downtime to a minimum.

Safety Considerations

Users should follow standard electrical safety practices when working with energized circuits. The ET310 is designed to handle the voltage levels associated with residential and commercial wiring. Proper use includes ensuring that the device’s contacts are insulated and that the tool is handled in accordance with general electrician safety guidelines.

Warranty and Support

Klein Tools offers support for the ET310 through its warranty program, ensuring that customers have access to assistance and replacement parts if needed. Contacting the manufacturer for service information or troubleshooting can resolve any issues that arise during use.

Why It Matters

Combining breaker locating with voltage testing into a single tool reduces the number of instruments a technician must carry, simplifying job sites and decreasing equipment inventory. This integration also speeds up the process of identifying faulty or improperly wired circuits, contributing to more efficient maintenance and repair schedules.