There can be other colors of hot wires in some systems as well but black is the most common. I am not sure if your whole circuit is 120v but theres a part answer for you.
Wiring A Ge Smart Switch In A Box With 2 Light Switches
Switch hot or neutral. The standard color for your hot wire is black. Hot and neutral come into the box and the hot immediately goes into a switch. That said cables always come with at least one white so in practice where cable is used for power and switch return from a fixture to a switch it is quite common for a white not to be a neutral. Think about it this way. The neutral is required to be unswitched by code and for basic safety. One disadvantage is the design and construction of the neutral pole and contacts.
You have an appliance box. Theoretically you can touch neutral oror ground and not get shocked as long as the hot is insulated or disconnected. The question is a bit long for me to follow fully but i will say that on a 120v circuit you are not aloud to switch the neutral. The light outlet or whatever is connected to the switch will not be energized. The bare hopefully solid copper wire is the ground. This is a diagram of a switch with a neutral.
If you see a black wire you should always assume its hot. If you interrupt the hot wire at the switch the power stops at the switch and can flow no farther. The black hot connection is broken to turn the light onoff the white neutral connection completes the circuit. The other day a manufacturer inquired about switching the neutral in a branch circuit and whether the 2011 national electrical code nec would permit a switched neutral for any application within the code. This minimizes any risk of shock that might occur if a wire comes loose within your project. You always switch the hot never the neutral.
However a 3 pole transfer switch with overlapping neutral contacts has several drawbacks. Always switch the hot side. While it is true that wiring the hot or the neutral wire to the switch will both break the circuit only wiring the hot wire will do it safely. I also had thoughts about overload protection in motor circuits and control. If the person who installed the wiring followed regulations the house wiring colors should give away the identity of the hot and neutral wires. It is a code rule.
On some manufacturers switches its not identical to that of the power poles and contacts. That way if the switch is open or the fuse blows the current in the hot wire will be prevented from proceeding beyond the switch or fuse into your circuit. My first reaction was no and then i thought about the differences between neutrals and grounded conductors. You should always place switches or fuses on the hot wire rather than on the neutral wire. Never switch the neutral. Since the neutral line is at or very near ground.
Gallery of Switch Hot Or Neutral
