Non metallic or nm 120 volt and 240 volt electrical cable come in two main. R wire red for power.

Neutral Wire Color Creative Safety Supply
What color is the common wire. Is that white or black wire. The gauge or size of the wire may change depending on the current requirement of the circuit but the color is a consistent feature. Electrical wiring color coding system electrical cable and wire color markings. Stack exchange network stack exchange network consists of 177 qa communities including stack overflow the largest most trusted online community for developers to learn share their knowledge and build their careers. Green in north america the common neutral conductor is white. One screw known as the common is a darker color than the others.
What color is the common wire. Back in the olden days thermostats were simple onoff devices that didnt need their own continuous power supply. If you recall your science classes in school you probably built simple circuits using a battery and a light bulb. Y wire yellow for air conditioning. The ground wire is green or bare. Note that colors may vary and the labeling on systems may be inconsistent.
Standard colors used for home wiring. He makes no recommendation for ungrounded power system colors. Your house wiring works on the same principle just on a larger scale and at higher voltages. Parts of a three way switch. A three way switch has four different screw terminals on its body. Grounding screws on.
As a neutral wire the white wire connects to. Electrical current travels from the source to the bulb then back to the source. However common practice per local electrical inspectors is for the first hot live or active wire to be black and the second hot to be red. The wire that carries the current from the power source to the outlet or receptacle is the hot wire. However red and black follows the coloring of the grounded systems in the table. The white wire is the common or neutral wire in a 100 volt service but the wire can also be gray in color.
The recommendations in table below are by wiles. Knowing the color code is essential for setting up the correct configuration of an electrical system and for safety. Usage of the ungrounded system is discouraged for safety. 2012 10 07 171652 2012 10 07 171652. C wire blue or black common for 24 volt power to the thermostat. G wire green for a fan.
There are other wires called travelers that carry current in more complicated circuits but. The other two screws usually a lighter brass color are known as the traveler terminals. The common wire is a trick that saves wiring and simplifies electrical panel design. Modern thermostats with wi fi and backlit display by contrast need a steady supply of juicethe c wire or common wire enables the continuous flow of 24 vac power to the thermo. The green screw attached to the metal strap of the switch is always for the ground wire this is the bare copper or green insulated wire within the circuit. 5 main types of electrical switches explained.
A white or gray wire can only be connected to another white or gray wire. Black insulation is always used for hot wires and is common in most standard household circuits. The wire that carries electricity to the source is the hot wire. W wire white for heat. What follows here is the standard coloring for wires throughout a home. In household wiring this wire is usually black though.
Whenever you see a black wire you know it is hot.