Depends on what your talking about in an outlet or car battery. A single pole single throw switch such as a light switch.
Wire A Thermostat
Which wire is common black or white. Sometimes youll find a white wire with a piece of black electrical tape wrapped around it. Black wire is hot wireand the white is the common or white is ground. The black wire is hot. The neutral wire can also be gray. The white wire is the common or neutral wire in a 100 volt service but the wire can also be gray in color. A white or gray wire can only be connected to another white or gray wire.
This wire isnt always hot though you also cant make any assumptions about whether theres power on the wire or not at any given point in time. Neutral common or return. The hot wire in a 120 volt residential ac circuit usually is coated with black insulation while the return or neutral wire is white. The wire that carries electricity from the bulb back to the source is the neutral wire or common wire. Power flows from the box to the outlet through the black wire and back to the box through the white one. In the most basic 110 volt electrical setup youll find two wires.
Black is hot because it carries voltage current. Step 4 place the prong of the multimeters black wire on the bare metal on the end of a white wire then read the meter. Hot when a white wire is augmented with a red or black color marking this often indicates that it is being used as a hot wire rather than a neutral wire. The white wire goes by many names that all mean the same thing. In a outlet the ground wire is green or bare copper. If you get a reading the black wire is hot.
In household wiring this wire is usually black though it can also be red. White wires with black or red tape. The positive wire on a multimeter is red and the black wire is negative. If both wires are black but one has a white stripe the striped wire is negative while the plain black wire is positive. The bare wire sometimes green is a ground wire tie directly to earth ground. Typically this is indicated with a band of black or red electrical tape but other colors may be used wrapped around the wires insulation.
If the multi colored wire is black and red the black wire is the negative wire while the red one is positive. 5 look in the owner manual to determine which wires are negative in a car. White is nuetral or common because it does not carry voltage current but provides a common tie point for the return path of current and is ultimately connected to ground. If you dont the black wire isnt hot. Is the white wire or the black wire the common wire in a 100 volt service.
Gallery of Which Wire Is Common Black Or White
