The 2 prongs on a plug, one is hot the other neutral, aka utility ground. The third is earth ground and is redundant.
My first thought when reading this was to not respond. But then after thinking about it for awhile I would be remiss if I did not.
/ /
NEC article 100 definitions.
Neutral Conductor. The conductor connected to the neutral point of a system that is intended to carry current under normal conditions.
Grounded Conductor. A system or circuit conductor that is intentionally grounded.
Informational note: Although an equipment grounded conductor is grounded, it is not considered a grounded conductor.
Grounding Conductor, Equipment (ECG). A conductive path(s) that is part of an effective ground-fault current path and connects normally non-current carrying metal parts of equipment together and to the system grounded conductor or to the grounding electrode conductor, or both.
The Grounded Conductor (neutral) and an EGC, (Equipment Grounding Conductor) are not interchangeable with with one another. The two serve entirely different functions.
The 2 prongs on a plug, one is hot the other neutral, aka utility ground. The third is earth ground and is redundant.
"utility ground" ???
"The third is earth ground and is redundant." No it is not a redundant ground ... It is an EGC as defined by the code...
The neutral conductor is a current carrying conductor and should never be used as a safety EGC.
A circuit neutral conductor is only grounded if it is connected to the electrical service Grounded Conductor.
Open Neutral:
An open neutral is where the neutral connection to the electrical service Grounded Conductor is broken, open.
An energized open neutral is dangerous and can be an electrical shock hazard or worse lead to death.
An energized open neutral? Where there is a connected load on a circuit (branch circuit wiring) and the neutral connection is broken, open, upstream (source end) from the connected load.
There will be a 120V difference of potential between the two broken conductors of the neutral. 120V as well from the load side open neutral to any grounded object.
As you can see it would be a bad idea to use a current carrying neutral conductor also as an EGC connected to the EGC ground terminal screw on a wall outlet or directly to the chassis of audio equipment.
( Existing 2 wire branch circuit wiring, (no EGC), 2 wire duplex receptacle is replaced with a 2 pole grounding type duplex receptacle outlet).
.