Which sequence correctly tests a GFCI device?

• A. Push the test button; plug in the tool; Try tool (should not operate); Press the reset button; Now the tool should operate.
• B. Plug in the tool; Push the test button; Try tool (should operate); Press the reset button; The tool should operate.
• C. Push the reset button; Press the test button; Plug in the tool; Try tool (should not operate); The tool should operate.
• D. Press the test button; Leave the tool unplugged; The tool should operate.

Answer: (A)

Testing a GFCI focuses on two things: that it shuts off power when a fault is signaled and that power is restored after resetting. The built-in test button is used to simulate a ground-fault condition; when you push it, the GFCI should trip and cut power to the outlet immediately. After that, you verify the absence of voltage by plugging in the tool and attempting to operate it—the tool should not run because the outlet is de-energized. Finally, you press reset to restore power, and the tool should operate again if the load is connected. This sequence confirms both the protective trip function and the ability to restore normal operation after an outage.