Quick Answer: The blue wire is the negative, or “return” wire.
If you open up just about anything electrical you’re going to be confronted with wiring that follows a specific colour code. Each colour signifies that particular wire’s function in the circuit as a whole.
You’ve got to make sure that you make yourself very familiar with this colour code before you attempt any repair work or new installations.
The general rule is to assume that every electrical wire is carrying a live current, and could severely shock you. If you’re ever in any doubt, don’t take any chances. It would be best to contact a professional who will help you out with your electrical work.
Since there are many coloured wires that you need to be familiar with, why not get a head start now?
What Do The Different Colours Of Electric Wires Mean?
Before jumping to the main colours, let’s know more about wires with colour coding! You were not aware, but all colours have different meanings.
The black wire is used for the transfer of power switches and outlets in every type of circuit. Black cables are also commonly utilised as switch legs.
It means it served as the connection link between a switch and the electric load. At all times, assume that black wires are live. Treat them as such.
Red wires are the secondary or backup live wire in all 220-volt circuits. Similar to black wires, red wires can also be used as switch legs at times.
Red wires are used to connect hardwired smoke detectors to the power system of your home. Linking two red wires or a red and black wire is possible.
Blue and Yellow Wires
Blue and yellow wires generally do carry power, but they aren’t utilised in standard outlet wiring. Blue and yellow wires are used as livewires that are pulled through a conduit. Yellow cables might be used as switch legs to ceiling fans, outlets connected to light switches and such.
Blue wires are most commonly used as travellers for three or four-way switches. (An example of a three-way switch is if you have a button on either side of the bed that control the same ceiling fan)
White and Gray Wires
If you ever come across wires in white or grey, know that these are neutral wires. White is more commonly used as a neutral wire colour, but grey is the same, too. The primary function of a neutral wire is to connect to the neutral bus bar.
The neutral bus bar is a conductive metal that attracts electric current for distribution through the house.
It sits within an electric panel. White and grey wires only connect. Even though they are named ‘neutral wires’, they may carry current. More so if there is an imbalance in the current load within the circuit. Be very cautious while handling these wires.
The primary function of the green wire is to ground the circuit. The cables connect from a grounding terminal within an outlet box, running to the ground bus bar within an electric panel.
Thus, green wires act as a failsafe for your electric circuit. If a livewire comes in contact with metal or any other conductive material, the green wires step in.
They allow the electricity to escape into the ground. Green wires only connect with other greens. Remember that if there is some sort of a fault anywhere in the circuit, they could be live. Be careful while handling them.
Now let’s come back to the question at hand.
Is The Brown Or The Blue Wire Positive?
It could be an LED light for the parking lot, or even lighting for a warehouse. The lights are following the international colour standard.
Brown, blue and green wiring is more common globally, compared to black white and green in the USA. The Brown wire is the ‘hotwire’, so you have to connect it to the building’s Black wire. The Blue wire is negative, so that would be connected to the white wire.
The Green Wire is the ‘ground wire’ that would be connected to your building’s green wire. If you’re looking at a circuit that’s over 220 Volts, you will most probably have multiple ‘hotwires’ that are connected to the Brown wire and Blue wire of your fixture.
Only run a higher voltage if it is indispensable. Most LED light fixtures do not require such high power. 110 Volts is more than enough for them to function correctly.
Safety Tip: Always remember to kill the power at the main electrical breaker, not only the switch. It is crucial when you are attempting any work involving electricity. Make sure to secure your connections properly, with the adequate equipment. When it comes to electric work, safety always comes first.
The Bottom Line
It is the age of DIY. There’s so much information available online. From self-help articles, to step by step tutorials and even videos of other people showing you precisely what you need to do. People take pride in fixing things and setting things up by themselves, rather than paying for someone else to do it.
The same goes for electrical work, too. For example, setting up new light fixtures, small problems with air conditioners, ceiling fans, etc. Many people are willing to have a crack at the main circuit board if there’s a sudden power outage or failure.
While it is good to be self-sufficient, there’s something significant to remember. Safety has to be the first on your list. There are substantial amounts of current flowing through different spots in your homes.
They power many lights and appliances, so the volume of the current can be very high. If you aren’t a hundred percent sure about what everything means, and what you have to do, it’s best not to. Don’t take a risk. Electrical injuries could be life-threatening.