Can someone please explain the difference between the below 4 outlet
configurations. I mean what are the dangers/benefits of the different ones?
Considering I have 3 pronged devices like tv's and refrigerators connected
1. GFI outlet with good ground.
2. GFI outlet no ground connected.
3. 3 Prong outlet with good ground
4. 3 Prong outlet with no ground connected.
The above two are essentially equivalent. Any hot-ground or
neutral-ground short (even weak ones like via your body)
in the device will cause the GFCI to trip.
In the former, a hot-case short will only blow a breaker if it's
a low-impedance short.
In the latter, a hot-case short will not blow the breaker and
will energize the metal case of any three prong device.
in 2 and 4, you don't have solid grounds, hence RF interference
(both in or out) is somewhat higher, and, you don't have a good
ground for surge suppressors.
A working GFCI is always safer shock-hazard wise than a 3 prong
outlet, grounded or not.
A ground is better for, er, grounding ;-)
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