North Carolina Home Inspector Practice Exam

When testing a GFCI outlet that is not grounded, how will the outlet respond when the test button is pushed?

1. It will reset automatically

2. It will test mechanically, but not electrically

3. It will trip and cut power

4. It will show a fault indicator

The correct answer is: It will test mechanically, but not electrically

When testing a GFCI (Ground Fault Circuit Interrupter) outlet that is not grounded, pressing the test button will engage the internal mechanism of the GFCI. The purpose of the test button is to simulate a ground fault condition, prompting the GFCI to interrupt the circuit and cut power. In an ungrounded scenario, the GFCI is still capable of operating correctly, as it will function by monitoring the current flowing in and out of the hot and neutral wires. While the lack of a ground does mean the outlet is not protecting against all electrical fault conditions, pressing the test button will still mechanically activate the internal components. This is why the outlet will test mechanically; however, because it is not grounded, it might not provide a standard electric response that would be observed in a properly grounded outlet. In essence, the testing action itself doesn't depend on grounding; it's about the GFCI's ability to detect imbalances in current flow. It’s key to remember that even without a ground, the GFCI will try to perform its function. Thus, while the test mechanism works mechanically, it may not fully simulate the complete conditions of an electric fault due to the lack of grounding.