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Understand Your Home’s Electrical System – Main Panel

Why Is It Important to Have a Working Knowledge of Your Home’s Electrical System?

When taking on any home electrical repairs, or tackling a small electrical project, the more you know about the system you are working on, the better prepared you are to complete the task.

When I started in the electrical trade back in 1981, my journeyman was instructing me on some of the basic tasks involved in wiring a house. After being told what spool of cable to use, and to pull it in from point A to point B, we moved on to learning how to “cut in” the cables (installing the cables in the outlet boxes and making the required splices). I was told things like:

♦ connect these ground wires to the box ground terminals,

♦ splice these white wires together,

♦ connect these black wires together along with two pigtails and,

♦ do nothing with these two black wires.

Instructions like these had to be repeated for every outlet box. After about a few hours of this, I asked him to explain not only what splices to make, but why? I wanted to know the bigger picture. To understand how an electrical circuit works meant that soon I could figure out for myself what splices needed to be made in each box without him having to show me every time.

That’s why I felt a need to create a new series of videos – to help you understand the big picture that is the entire electrical system in a typical home.

Starting With the “Nerve Center” of Your Electrical System – the Main Breaker

I’m going to start with the main distribution panel. The individual videos that follow will trace each and every circuit in my panel from the beginning to the end device (s) that is fed from that circuit breaker. The goal is to give you a solid understanding of the entire system, and should something go wrong, you will have a better idea of where to look for a problem, and what needs to be done to correct it.

In this, the first of the series, I’m going to explain the nerve center of your electrical system, the main service entrance and panel. This is where the electricity from the utility supply enters your house, and is then distributed to the individual circuits throughout the home.

The Key is Understanding How to Work Safely

I have observed over the years that many of my website and YouTube visitors are quite willing to learn about and delve into problems or projects involving various outlets (light fixtures and switches for example), but if it involves the main panel, many will back off. This can be, and usually is a good thing.

However, knowledge is power (no pun intended), and if you understand that scary monster known as the service panel, there really isn’t anything to be afraid of. The key is to work safely, and the basic rule of safe work around electricity is to turn off the power! Same goes for the main panel.

How Power is Distributed Through Your Home

In most cases, your home has a combination service panel that has a main breaker. When you shut off this main breaker, it disconnects the power going into the distribution section of the panel, where all the branch circuit breakers are. If you arrange for an alternate source of good lighting in advance, it’s really not scary at all!

The power comes to your home through a power meter, and then to your main breaker. This part you should never touch. This is energized from a main distribution transformer, and can only be shut off by contacting your service provider.

The main breaker controls the power to the buss bars in the distribution section of the panel. The branch circuit breakers connect to the buss bars, and then feed the power through to the load terminal, and you connect the hot wire(s) (black and/or red) for the branch circuits to the load terminals of the breakers. The neutral (white) conductors for the branch circuits connect to a common neutral buss bar, and the ground (grounding, earthing) (green or bare) wires connect to ground lugs or bars that are common to the panel case or frame.

A picture (and better yet, a video) is worth a thousand words…..

What is your comfort level with the main panel in your home? Feel free to share your experiences, thoughts or questions below.

Don’t forget to subscribe to my YouTube Channel. By subscribing, you will be the first to know when a new video in this series is ready for viewing, as well as any other video content uploaded to the channel and to the website.

Terry Peterman, The Internet Electrician®

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The Basics of Household Wiring DVD

"If you're looking for a good reference to help you understand simple home wiring, I personally recommend 'The Basics of Household Wiring' DVD".

Terry Peterman, the Internet Electrician
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