First of all, the correct term is 'line' and not'phase' wire. The reason a switch is always placed in the line conductor, rather than in the neutral conductor, is that its function is not simply to break the circuit, but also to ensure that the circuit's load is disconnected from the line potential. If the switch were to be placed in the neutral conductor, it would still break the circuit, but the load will still be at line potential and present a shock hazard to anyone attempting to work on the load (e.g. to remove a lamp from its holder).
because its much safer to switch the hot wire then the neutral wire because if you are working on a light fixture for example and the switch is off if you ground yourself out to the neutral you become the load or return. a neutral shock can me more dangerous at times
motherboard
You should never switch the neutral wire. The neutral of the appliance should be connected directly to the neutral wire leading to the service panel neutral bar.
No, the switch just breaks the hot side of the circuit. The incoming hot wire should be connected to the top screw and the load side of the switch should be connected to the bottom screw. The neutral wire is usually connected together with a wire nut and pushed to the back of the switch box.
It sounds like your switch is a three way switch. The wire that is on the different colour screw of the three screws will either be the "hot" wire or the wire to the load. The neutral might or might not be in the box that the switch is in depending on which end of the three way system you are at. See discuss question button below.No wires connected to a switch are neutral. A switch breaks the circuit of the hot wire. Black AND red are hot wires. White is used for neutral and is almost never connected to a switch.
because its much safer to switch the hot wire then the neutral wire because if you are working on a light fixture for example and the switch is off if you ground yourself out to the neutral you become the load or return. a neutral shock can me more dangerous at times
motherboard
The speed sensor wire is connected to the speed sensor and goes to the speed sensor relay switch. The speed sensor relay switch is connected to the computer by a separate wire.
High or "wild" leg phase to ground.
You should never switch the neutral wire. The neutral of the appliance should be connected directly to the neutral wire leading to the service panel neutral bar.
No, the switch just breaks the hot side of the circuit. The incoming hot wire should be connected to the top screw and the load side of the switch should be connected to the bottom screw. The neutral wire is usually connected together with a wire nut and pushed to the back of the switch box.
(Note: this is US information. Other countries may use other color codes; consult an electrician in your local area.) Standard color coding for single-phase electrical wiring is that the neutral wire is white and the "hot" wire is some other color, usually but not always black. If the switch has instructions or a wiring diagram, follow that. If not, normally the white wire should be connected to the lighter (silver colored) terminals on the switch and the "hot" wire should be connected to the darker (brass colored) terminals. Some switches interrupt both electrical paths, and in those the terminal screws may be the same color and it doesn't matter which wire goes to which set of terminals (just don't cross them). If there are green terminal screws, those are for the green grounding wire.
Yes
A delta connected appliance can be connected to a 3-phase system by leaving the neutral unconnected. The appliance must be properly earthed.
It sounds like your switch is a three way switch. The wire that is on the different colour screw of the three screws will either be the "hot" wire or the wire to the load. The neutral might or might not be in the box that the switch is in depending on which end of the three way system you are at. See discuss question button below.No wires connected to a switch are neutral. A switch breaks the circuit of the hot wire. Black AND red are hot wires. White is used for neutral and is almost never connected to a switch.
The ground wire must remain connected to the box. The frame of the switch, and therefore also the screws, must remain connected to the box as well.
The radio was wired wrong. Sounds like the hot wire for the radio was connected to the hot wire for the headlight switch.