It is very important to know which wire is positive and which is negative, especially when dealing with electrical wirings. You can easily identify it by the color of the wire.
However, you may find white and black wire and get confused that which one is positive and which is negative. Don’t worry at all, it is not as confusing as it looks.
We have explained how you can identify the positive and negative wires and you will learn by the end of this article whether black is positive and white is negative or not. So, let’s find out below.
Caution: We have provided the basic information about positive and negative wires in this article. As dealing with wires is risky, you always need to ensure the positive and negative wires or seek help from professionals.
How to Determine the Positive and Negative Wires Based on Color?
The color of a wire indicates whether it is positive or negative. However, it may vary on the type of current. Let’s check them out.
Wire Color for Direct Current (DC)
The source of DC power is batteries, solar cells, and fuel cells. In this power methodology, the electricity flows in one direction. Direct current (DC) usually contains 2 to 3 electrical wires. Here are the types of wires:
- The RED wire is Positive.
- The BLACK wire is Negative.
- The WHITE wire is Neutral.
However, if a DC source has two wires – one is black and another one is a white stripe, then the black wire is positive and the stripe wire is negative.
Wire Color for Alternating Current (AC)
Alternating Current (AC) normally comes from the power outlets. It passes electricity in two directions and handles 110, 220, or 440 volts. The alternating current usually uses 3 wires and a maximum of 5 wires to handle electricity. All colors of wires bare an individual sign which are:
- The BLACK wire is the Positive or Hotwire Phase 1. It passes electricity from the power outlet to the switch.
- The RED wire is also Positive but the Black is Primary. It is also called Phase 2 Hotwire.
- The BLUE wire is Phase 3 Hotwire.
- The WHITE wire is Neutral.
- The GREEN wire is the Ground wire.
Wire Color for Appliance Plug or Power Cord
The appliance plugs or the power cord don’t have any positive or negative wire. One wire if the plug is hot and another is neutral. So, it doesn’t matter whether you are putting the plug into the positive port or the negative port.
What Color Is Positive – Black or White?
The black wire is always Positive unless it is installed in the negative port from the power outlet. The black wire is the primary phase 1 Hotwire and it passes electricity from the power source to the switch.
The white wire is normally neutral. But if the cable has only two wires – black and white, then the white wire is the negative wire. However, if the white wire is marked red or black, then it means that it is no longer a neutral or negative wire, rather it is the hot wire or the positive wire.
How to Identify Positive and Negative Wire?
If you follow the standard, then the black wire is positive and the white wire is negative. But if someone installs it by mistake and you go to work with that cable, it can be dangerous for you.
Again, if you accidentally, connect the negative wire to the positive port, and the positive wire to the negative port, then it may cause a short circuit and for AC power, it may put your life at risk.
So, it is important to check and ensure which one is the positive wire and which one is the negative wire. If you don’t know how to check that, then don’t worry, here are the instructions on how you can do that:
Step 1: You need to use a digital multimeter to figure out whether the wire is positive or negative.
Step 2: Connect the red clip to one end of a wire and the black clip to another end of that wire.
Step 3: Follow the reading screen of the device. It will show a number that defines the voltage.
- If you see the + (Positive) sign before the voltage, then it means the wire is Positive.
- If you see the – (Negative) sign before the voltage, then it means the wire is Negative.
Bonus Tip: Standard Positive and Negative Wire
- The Stripped or Ribbed wires are always Negative.
- The Extension cords always have Negative wires.
- The Speaker cords always have Positive wires.
- Plain black wire is always positive.
- For multi-colored wires, the Red wire is Positive and the Black wire is Negative.
- Do not touch the wire with a wet hand.
- Do not touch the wire if you are not sure what the wire is for.
- Use gloves before dealing with electricity.
- Do not work alone if you are unskilled.
Frequently Asked Questions
Is Black Positive or Negative?
For DC power, the red cable is positive and the black cable is negative. So, if you are using a battery or cell then the black wire is Negative. On the other hand, if you are using AC power, then the black cable is positive and the other cable is negative. Never connect the black cable to the negative terminal when you are using the alternating current as the power source.
Is White a Positive or Negative?
It depends on the number of wires in a cable whether a white wire is negative or neutral. Usually, the white wire is never used as positive. If the cable has three wires – black, red, and white, then the white is the neutral wire. On the other hand, if the cable has two wires – black and white, then the white wire is negative.
What Is a Black and White Wire?
In a random electrical wire, the black wire is the hotwire or the positive wire. It carries the electricity from the power breaker to the switch. The white wire is the neutral wire which carries the unused electricity back to the breaker point from the switch. However, the white wire sometimes uses as the negative wire.
Why is white positive and black negative?
Generally, a black is a positive wire in AC power outlets. But if someone mistakenly used a white wire on a positive outlet, then it may happen that you will find the black wire as negative and the white as positive. However, in DC power such as batteries, the black wire is always negative and the other one is the positive wire.
What Is the Color Code for Electrical Wiring?
Here is the color code for electrical wiring:
Alternating Current (AC)
- Black – Positive (Primary), Hotwire, Live wire, Phase 1.
- Red – Negative, Live Wire, Phase 2.
- Blue – Positive (Secondary), Hotwire, Phase 3.
- White – Neutral.
- Green – Ground.
Direct Current (DC)
- Black – Negative
- White – Neutral
- Red – Positive
Hopefully, this guide has proven helpful to you in determining whether the black wire is positive or not. If you are dealing with AC power that has a black and white cable, then the black one is positive and the white one is negative. However, it is the opposite in DC power where the black wire is the negative one. If you find no other color except black, then use a multimeter and check which one is positive and which is negative as instructed above. If you have any suggestions, then feel free to tell us in the comment section below.