Black red and yellow is three-phase. there is no neutral.
In electrical wiring, the live or "hot" wire is typically brown or red, the neutral wire is typically blue or black, and the ground wire is yellow or green. So, in this case, the brown wire is likely the hot wire, the blue wire is the neutral wire, and the yellow green wire is the ground wire.
The three wires in a plug are typically called live, neutral, and earth wires. The live wire carries the current to the appliance, the neutral wire completes the circuit and carries the current back, and the earth wire is a safety feature to prevent electric shocks.
Be careful. Grey and yellow wires are typically used on 277/480v systems. Confirm you have the right voltages before connecting your equipment. If wired in a typical manner, the yellow wire is your hot (black) and grey is your neutral (white). The purple may be a hot or may be a switch leg or serve some other purpose. I suggest if you can't confirm this information you hire someone to do it for you. You might get yourself hurt or dead or start a fire.
3 colors? red black green and yellow? i count 4... red is your active, or live wire. black is return, or negative wire. green is your earthing wire and yellow is more than likely a control, for a switch, possibly a heating fan or towel railing?
Your local electrical codes will tell you what color the wires should be. In the United States, you should not see yellow wires in household electrical wiring. For 240V, you should either have two black wires or a black and a red, but once again that falls back on the local electrical codes. A yellow wire may be a white wire that is showing its age. If this is the case, then it should read around 0V to ground if everything else in the circuit is correct.
In electrical wiring, the live or "hot" wire is typically brown or red, the neutral wire is typically blue or black, and the ground wire is yellow or green. So, in this case, the brown wire is likely the hot wire, the blue wire is the neutral wire, and the yellow green wire is the ground wire.
If both wires are black then the one with the writing is the neutral wire. If the two wires are black and white then the white one is the neutral.
The three wires in a plug are typically called live, neutral, and earth wires. The live wire carries the current to the appliance, the neutral wire completes the circuit and carries the current back, and the earth wire is a safety feature to prevent electric shocks.
Be careful. Grey and yellow wires are typically used on 277/480v systems. Confirm you have the right voltages before connecting your equipment. If wired in a typical manner, the yellow wire is your hot (black) and grey is your neutral (white). The purple may be a hot or may be a switch leg or serve some other purpose. I suggest if you can't confirm this information you hire someone to do it for you. You might get yourself hurt or dead or start a fire.
If both wires are black, the one that connects to your white wire is the one that should have little writing on it. Black to the plain black wire, white to the wire with writing.
Your black wires are your hot wires. The white is your neutral or common. It would be best to run an equipment ground (green wire) too.
If this is a home wiring question and the wires are black and white then black is Hot and white is Neutral. If you also have a red wire, it is the other hot wire, and either the black or the red wire to the white one would be 120 volts, and red to black would be 240 volts.
3 colors? red black green and yellow? i count 4... red is your active, or live wire. black is return, or negative wire. green is your earthing wire and yellow is more than likely a control, for a switch, possibly a heating fan or towel railing?
Your local electrical codes will tell you what color the wires should be. In the United States, you should not see yellow wires in household electrical wiring. For 240V, you should either have two black wires or a black and a red, but once again that falls back on the local electrical codes. A yellow wire may be a white wire that is showing its age. If this is the case, then it should read around 0V to ground if everything else in the circuit is correct.
The red wire is the positive wire. The black wire is the ground wire. The green and yellow wires are the speaker wires. The white wire is the auxiliary wire.
In an electrical circuit, the red wire is typically considered the hot wire, while the black wire is usually the neutral wire.
To properly wire a light fixture with 3 sets of wires, first identify the hot (black), neutral (white), and ground (green or bare) wires in each set. Connect the hot wires together, the neutral wires together, and the ground wires together using wire nuts. Then, connect the fixture's hot wire to the group of hot wires, the neutral wire to the group of neutral wires, and the ground wire to the group of ground wires. Finally, secure all connections with electrical tape and install the light fixture according to the manufacturer's instructions.