Re:Why we ground electrical systems (2015)
by fsh on Friday August 02, 2019 @03:31PM
(#20595875)
And the neutral is tied to (earth) ground. Otherwise all metal devices would shock you if you touched something earth referenced, such as a radiator, at the same time.
Edit to clarify: In principle, only the voltage difference between Live and Neutral matters for running a device. So theoretically one could construct a building supply where Neutral is not at earth potential. However, EGC has to be at earth potential, otherwise there would be a voltage between any metal electronic device and earthed objects, such as radiators or your feet standing in a puddle. This means that in practice both Neutral and EGC are always physically connected to the earth in some way and have to be for the system to work properly.
Edit to clarify: In principle, only the voltage difference between Live and Neutral matters for running a device. So theoretically one could construct a building supply where Neutral is not at earth potential. However, EGC has to be at earth potential, otherwise there would be a voltage between any metal electronic device and earthed objects, such as radiators or your feet standing in a puddle. This means that in practice both Neutral and EGC are always physically connected to the earth in some way and have to be for the system to work properly.