Home Electrical Wiring

Everything You Need to Know About Home Electrical Wiring

Ian Mutuli
Updated on
Ian Mutuli

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
Get Smarter On Architecture and Design

Get the 3-minute weekly newsletter keeping 5K+ designers in the loop.

Enter your Email to Sign up

People depend on electricity, but understanding its operation can be difficult. A problem with your electrical supply can be confusing. The problem might not be easy to fix, and professional assistance might not be available right away. A homeowner should be familiar with the basics of electricity and some of the terms associated with electrical work. Whether you need to update your switches or are replacing your home transformers, having the proper knowledge will help you finish the job safely. Let's take a closer look at what you need to know about home electrical wiring. 

Wiring Types

It can be overwhelming when you open up your electrical panel and are faced with a tangle of various colored wires. Knowing what each wire is for is the first step to understanding your electrical problem.

Black Wires 

  • Due to their electrical conductivity, they are known as "hot wires." There is no switch to turn them off, so they always remain on. A black wire carries high voltage and little current.

Yellow Wires

  • Heavy appliances such as stoves and ovens use blue and yellow wires. A minimum amount of electricity is required to power these appliances, which is more than the electricity needed to power lights.

Green Wires

  • The grounding terminal on the outlet box is connected to these wires. Any electrical device can be shut off by cutting off the current.

White Wires

  • Electricity is sent back to the ground through these wires, typically concrete outside your home, by providing an alternate path. During an electrical malfunction, electricity does not pass through you.

Red Wires

  • As soon as appliances or lights use electricity, it is returned to the utility company through the "neutral" switch. Low voltage, high amperage electricity is sent through red wires by a utility company's generator.

Bare Copper

  • A grounding wire is usually made from bare copper.

Connections and Meters

Residential panel electrical wiring begins with the connection point. Meters measure the monthly electricity consumption of your household and communicate this information to the power company. Electricity is distributed throughout the house by the electrical panel. To control electricity in your home, there is a circuit breaker near the meter. Black wires run underground from your meter to your neighbor. This electrical wire also powers your home. Service entrance conductors are large copper bars connecting to your house's panel. 

Circuit Breaker Panel

Circuit breakers connect all of the electrical wires in your home. Every breaker on the main service panel controls a different electrical circuit; between 100 and 200 breakers are usually located there. Load and line service panels are the two main types. Wires connect to the panel on the load side, while power lines enter the house on the line side. Any electrical system work should be performed on the load side. Before you begin working on these panels, you should turn off the power from the panels to the meter.


Most homes have plastic or metal electrical boxes. A house's electrical system typically has many breakers and fuses that trip if the voltage is too high, as well as the various rooms' wiring. A junction box should be in each room of the house. Color-coded wires run to these boxes. A 3-way switch will require two more white wires to come out of this junction box. 


Devices are powered on or off by switches. An outdoor breaker box is usually located near the entrance to the house, or an indoor breaker box can be found near the door. Switches are often controlled manually with screws. When mounted on a wall, most switches also include an electrical box. The wires of the power lines connect directly to the lugs on the switch in such cases. Outlets and switches both come in 15- and 20-amp versions. A small triangle next to the switch number indicates an amperage load.


The electrical outlets that supply power to your home's appliances and devices are called receptacles. Understanding how an outlet is wired is essential. There are two types of home outlets: 15-amp and 20-amp. A 15-amp outlet has a different color code than a 20-amp outlet.

In the middle of an ordinary home outlet, there are two horizontal and two vertical slots. Wide blade plugs can be accommodated in the left slot, which is wider than the other two slots. Under the right side slot, there is a round hole for grounding but no cut-out in the middle. In some outlets, you can plug in a load up to 15 amps, while others are designed for loads up to 20 amps.

If you have no home electrical experience, it's crucial that you learn the basics. If you are nervous about attempting simple electrical tasks, it's always best to bring in a professional electrician. 

Ian Mutuli

About the author

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.