BasicB-003-019-006
Where should the green wire in a three-wire AC line cord be connected in a power supply?
B
Answer
Basic radio theory
Type
A
To the white wire
B
To the chassis
C
To the fuse
D
To the "hot" side of the power switch
Answer Notes
In standard North American AC wiring, the green wire (or bare copper wire) is the designated equipment ground. Its primary purpose is safety: it connects the metal chassis of the equipment directly to the earth ground of the electrical system.
By connecting the green wire to the chassis, any internal fault that causes a live wire (the 'hot' wire) to touch the metal casing will immediately short to ground. This rapid surge of current trips the circuit breaker or blows the fuse, removing power and protecting the user from a potentially fatal electric shock.
Connecting the green wire to the white (neutral) wire, the fuse, or the hot side of the switch would defeat this critical safety mechanism and create a severe shock hazard.
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