Re:Why Three Prongs? (1996)
by amluto on Monday July 08, 2019 @11:35AM
(#20383613)
> The statement is predicated on the entire system being ungrounded (i.e., everything on your side of the transformer).
This is not possible for AC due to capacitive coupling between everything. In a large-ish ungrounded AC distribution system, a fault from one phase to ground will carry a large amount of current due to capacitive coupling from the other phases to ground. To reduce this current, an inductor can be installed from neutral to ground [0].
Even for use within a single room, a safe isolated AC system is complicated [1]. If you’re doing benchtop AC experiments, you should not use an isolation transformer — you should use a GFCI.
This is not possible for AC due to capacitive coupling between everything. In a large-ish ungrounded AC distribution system, a fault from one phase to ground will carry a large amount of current due to capacitive coupling from the other phases to ground. To reduce this current, an inductor can be installed from neutral to ground [0].
Even for use within a single room, a safe isolated AC system is complicated [1]. If you’re doing benchtop AC experiments, you should not use an isolation transformer — you should use a GFCI.
[0] https://circuitglobe.com/peterson-coil-grounding.html [1] https://www.pglifelink.com/line-isolated-monitors