Residential Electrical Wiring Tips

By Mark J. Donovan

Though not a licensed electrical contractor I have a degree in electrical engineering, and over the past 20+ years have wired a number of homes and home additions, with the oversight of a licensed master electrician. From my experience I have acquired a number of residential electrical wiring tips. Below I share with you some of these tips to hopefully help you from electrocuting yourself and to ensure that your home’s electrical wiring meets the future demands of your family.

Residential Electrical Wiring Safety

First and foremost, when working with residential electrical wiring remember one important maxim. “Electricity can kill”. It is important you fully respect it when working on electrical wiring in the home.  In many municipalities you may not even be allowed to work on it, and in most cases you will need a permit at a minimum.  In my experience local building inspectors will provide homeowners permits for small projects if they present an electrical wiring diagram plan and can demonstrate some level of basic electrical wiring knowledge.

A couple of key things to remember when it comes to residential electrical wiring:

• Black and Red wires are typically “Hot” meaning current (Amps) are flowing from the circuit breaker to the appliance or electrical box.

 

• White wires are usually the “Returns” where current (Amps) will return back to the circuit breaker after passing through the appliance/load.

 

 

• The ground wire is normally bare and attaches to the appliance frame. Normally current should not be running through it. The only time current should be running through it is when there is a short circuit, and when this does happen the circuit breaker should trip killing current flow to the appliance and wire.

 

• White and ground wires should not be connected together, except back at the circuit panel bus bar. If so, every time the appliance is turned on, electricity will flow through both the white return wire and the ground wire which is a dangerous situation.

 

Circuit Panel and Circuit Breakers

The second most important maxim to remember when building a new home and installing your home’s electrical wiring is. “You can never have enough circuit breakers.”

As our homes today become increasingly filled with home theater systems, multiple computers, fancier lighting systems, and other new age kitchen appliances, residential electricity demand continues to rise. Gone are the days when 100 Amp circuit panel is sufficient.

This said, when meeting with your electrical contractor ask for a minimum of a 200 Amp circuit panel with 40 locations for circuit breakers. You may not initially need all of the circuit breaker locations, but over time you probably will. For example if you install a pool or build a home addition later on you will need additional circuit breakers.

If you are unfamiliar with a circuit panel, it is where all of the wires in your home get tied into and connected to circuit breakers. These circuit breakers are fed by one large circuit breaker that connects your home to the local electric grid. Typically each circuit breaker is targeted towards a specific room within the home. In some cases there may be multiple circuit breakers for a room.

There are national, state and local residential electrical wiring codes that specify the maximum number of outlets, switches and appliances that can be on a circuit breaker. Also, circuit breakers come in different shapes and sizes with different current rating capacities. The electrical codes also specify the current capacity of the circuit breaker for particular rooms. They also specify the types of rooms that need ground fault interrupt circuit breakers. For example, typically kitchens and bathrooms will require 20amp ground fault circuit breakers due to the number of appliances that are used in these rooms and the higher risk of electrical shock. Ground fault interrupt circuit breakers are designed to trip in the event an electrical appliance comes in contact with water, thus potentially saving your life.

Residential Electrical Wiring

Another important residential electrical wiring tip is the choice of electrical wiring. Many codes only require the use of 14-2 wire, which consists of a black, white and bare ground wire that is typically tied into a 15-amp circuit breaker. Again, with the increase of electronic technology in the home I would suggest using 12-2 wire in all rooms. This is a thicker wire usually used in conjunction with 20amp circuit breakers. With more current carrying capacity you will have less chance of tripping circuit breakers when the home theater, computer and vacuum cleaner are all running simultaneously. If you have kids, you know this is possible.

Also, if you plan on building a workshop in your garage or basement you’ll definitely want to use 12-2 wire. I’ve been in too many homes where I turn on the table saw and trip the circuit breaker because someone else was simultaneously using an electric drill.

Location and Height of Electrical Outlets

Again, codes dictate minimum heights off of the floor and maximum distances between outlets. However, I typically install outlets so that the bottom of the box is 16 inches off the floor. I also try to install outlet boxes near where I anticipate furniture to reside.

Location of Electrical Switches

When installing light switches carefully consider the locations of them. You don’t want them installed behind doors. You want them to be intuitively located when walking into the room. Usually you will want to place them within arm reach of the doorway at a height of 48 inches or so off of the floor.

Also consider 3-way switches, which means you can turn the light off at two locations within the room. This is particularly helpful if there are two ways of egress from the room. Don’t forgo this type of switch, if your wiring your own home or room, just because it seems too complicated. You will regret your decision over an over. A 3-way switch is not too complicated. It just requires the right type of switches (two 3-way switches) and reading the wiring instructions in the 3-way switch packaging. You can also find instructions online.

Installing Ceiling Lights and Ceiling Fans

When installing ceiling/wall lights and ceiling fans, assemble them as much as possible on the ground to eliminate neck strain and the need for having another set of hands to hold them up when installing them.

Use the Right Tools

Always use the right tools when installing residential electrical wiring in your home. Pliers and screwdrivers should have insulated grips. Also, needle nose pliers are great for creating the loops in the wire to fasten the outlet/switch screws to. In addition, use insulated wire stripping tools for stripping wires. Finally, there are also some inexpensive casing strippers to help to quickly remove the white casing around the 12-2 or 14-2 wire.

For information on Changing a Light Switch, See HomeAdditionPlus.com's  "How to Change a Light Switch Ebook". It provides detailed, easy to understand, step-by-step instructions and pictures, on how to replace a Light Switch.