The GFCI/RCD: A Simple but Life-Saving Protector
Why Home Improvement Stack Exchange recommends it
DIY Stack Exchange (Home Improvement) users link it when explaining that a GFCI looks for current imbalance rather than using the ground wire, and how the test button works.
Recommended by 1 people across 1 different months, 2020 to 2024.
What it is
A 16-minute explainer from Technology Connections on what a GFCI (also called an RCD) is, why homes and businesses need one, and how it detects a ground fault by comparing current on the hot and neutral wires. It also covers the test button, which creates a deliberate imbalance with a resistor.
What people said
Recommends Greg · 2020-09 · Home Improvement Stack Exchange · on “I'm getting a fake short on my fuse tripping GFCI”
It does slip my mind that GCFI measures imbalance rather than amp spikes and etc. Thank you, its good to learn that about transformers [this video] has a good video as well Thanks
Cites Eric Stdlib · 2024-02 · Home Improvement Stack Exchange · on “Why does a GFCI test button work during a power outage?”
I have a GFCI receptacle (commonly found in North America) in my home. Recently I switched the power to the outlet off using the circuit breaker, then pressed the "Test" button on the outlet. To my surprise, the outlet tripped. The outlet does not reset unless I switch the power back on using the circuit breaker. Why does the GFCI test functionality work when there is no power? I watched a youtube video [this video] by Technology Connections regarding the GFCI receptacle. At 12:40 the video mentions that when the "Test" button is pressed, a resistor creates an intentional ground fault and causes the receptacle to trip. I also read parent US5757598A [LINK] . In Fig. 1, SOL1 receives power from the
Cites Harper - Reinstate Monica · 2024-06 · Home Improvement Stack Exchange · on “New Eaton AFCI/GFCI 40A 220V GFCI breaker signals (4 blinks) ground fault”
A GFCI breaker is not grounded at all. There is no way for a GFCI breaker to access ground. However, that is fine, since GFCIs don't use ground in any way. They are looking for differential current on the wires (i.e. current unaccounted for, that went out and did not return via this path). [this video]