Your home will have multiple circuit breaker types. As the name implies they break the current for circuits in your home. This would happen for one of two reasons. One the circuit gets overloaded or a short occurs. The breaker will trip before the wire gets too hot. The other would be the ability to manually shut the power off to work on the electric or a device.

Not sure if this is the right place? See the article on 'Basic House Wiring' for information on all the wiring topics. Got an electrical project that you need to get done? See 'Wiring Electrical Fixtures' and 'Home Electrical Repair' for a listing of all the related articles.

Breaker Types

The following is a brief overview of the various circuit breaker types found in most residential homes:

Single Pole Breaker - This breaker works on one side or 'pole' of your 240 volt service. Thus, it controls a 120 volt branch circuit. The amperage can range between 15 and 30 amps with 15 and 20 amps being the most common. This type of breaker will be used for outlets and lights in your home. They can also be used for individual circuits that require 120 volts, such as furnaces, washing machines and sump pumps.

Double Pole Breaker - This circuit breaker type picks up both poles of a 240 volt service. So this type provides 240 volt power to the circuit. They are used for appliances like ranges, ovens, dryers and water heaters. Double pole breakers can go up to 100 amps or more. Higher than fifty amps is usually to feed a sub panel somewhere else in the home.

GFCI Breakers - Ground Fault Circuit Interrupters are for circuits that service areas of your home where water is present. Bathrooms, kitchens, garages and outdoor receptacles all require GFCI protection. This type of circuit is not always opted for, since it can involve an lot of extra wire to pick up the individual wet location devices. GFCI protections can also be achieved by installing protected outlets at key spots.

AFCI Breakers - Arc Fault Circuit Interrupters protect against arcing that can cause fires. Home built since 2008 are required to have arc fault protection for bedrooms and living spaces. These breakers generally have a gray color and a special reset switch on them. The wiring in older homes may not allow for the use of an AFCI Breaker.

Half Size or Mini Breakers - Standard single pole and double pole breakers are available in a half size model by many manufacturers. Standard single pole breakers are 1" thick and a 'Mini' will be 1/2". this a great feature for adding circuits to an existing panel. The panel box must be set up for the use of mini breakers. Some panels do not allow for them or only allow for a certain number.

Adding Circuits

The ability to add circuits to a panel box will depend on a couple of factors. The first would be the load on the panel. Is the main breaker large enough to accommodate another circuit. The second would be available spaces. For a panel that is filled you may be able to purchase half size or mini breakers. You can put two of these in place of one full size breaker. See the article 'Adding a New Circuit Breaker', for more information.

Breakers are usually specific to the panel manufacturer. Some are interchangeable but it best to check and make sure the breakers are compatible with the panel you have. Take one with you to be sure.

Replacing Breakers

Yes, circuit breakers can go bad. They usually fail on the side of tripping when there is no overload. When they go bad, the only option is to replace the breaker.

Another reason to replace a breaker would be to change the type, although this would be uncommon. You could add a GFCI breaker to your panel if wanted to cover a group of plugs with this protection, maybe in your garage as an example.

The two key concerns for replacing a breaker are: First, getting the right one and Second shutting the power to the panel off before you attempt to change the breaker.

For a complete discussion on replacing a breaker, see the article 'How To Replace a Circuit Breaker'. This information will provide step by step information changing out the breaker.

The basic house wiring in homes built in recent decades have copper wire in them. Houses built in the 1970's may have aluminum wire in them. Aluminum wire has been linked to fires and is no longer allowed in most places. If you encounter aluminum wire in your home you may want to have an licensed electrician check it out.

Got an electrical project that you need to do? See the articles 'Home Electrical Repair', 'Residential Wiring Projects' and 'Basic House Wiring' for a listing of do it yourself projects that a homeowner can accomplish.

Wire or Cable?

Sometimes we use these terms interchangebly and there is nothing wrong with that. Technically speaking 'Wire' is the individual strands that are used for various purposes in an electrical installation. Wire can have insulation or be bare. It can also be made of different materials. However, most wire used in residences that is available for purchase is copper.

Wire

Wire comes in several gauges. The gauge of the wire is simply the diameter or a way of specifying how much current it can carry. Wire gauges that you are likely to encounter in your home are sized from 24 to 6. Guage sizes are counterintuitive since the larger the number the smaller the wire is. A wire rated 24 AWG is a very thin wire that you would use on a doorbell or garage door opener. Wire that is rated 6 AWG would be used for an electric range or an central airconditioning condenser.

Common Wire Sizes In Your Home

Amperage for Wire Sizes

16 - 24 gauge low voltage

14 gauge 15 amps 1440 watts (120) volt

12 gauge 20 amps 1920 watts (120) volt | 3840 watts (240) volts

10 gauge 30 amps 2880 watts (120) volt | 5760 watts (240) volts

8 gauge 40 amps 7680 watts (240) volts

6 gauge 55 amps 10560 watts (240) volts

Wire Colors

Bare

Not really a color, but worth mentioning. The bare wire if there is one, is always the ground wire. Inside of 'Romex' or NM-B cable, the ground is bare and it is wrapped with kraft paper.

White

Black, Red, Blue, Orange, Yellow, etc....

Wire Insulation

THHN; THWN

Bare

Wire Types

Solid

Stranded

Cable

Cable generally refers to a group of wires. The wires are not necessarily all the same size and are usually different colors. Cable is shielded with either abmetal or plastic casing. This serves to protect the wires. Inside the cable the individual wires will also have a plastic insulation. Sometimes the ground wire inside of a cable will not have any insulation.

Cables can have different quantities of wires. They can also have different gauges in them. Most of the time when you are talking about wire, you mean a cable that has all the conductors that you need for a particular application.

Shielded cable is usually three or four wires. A designation such as 12-2 w/Ground or 10-3 w/Ground refers to the wire gauge and number of conductors. The first number is the gauge. Standard gauges are #14, #12, #10, #8 and #6. The second number indicates the number of insulated conductors. A "2" would mean a black and white wire. A "3" will likely mean a black, red and white wire. The w/Ground would mean that it has a bare ground wire inside also. Almost all shielded cable, that is sold today, comes with a ground wire in it.

Cable Designations

There are certain designations for cables that tell you what it is used for in general. For residential applications, you will likely run into three different types. The desinations are listed below:

NM-B

NM = Non Metallic, B = Temperature Class (194 deg farenheight). This is probably the most common wire you will find in your home. It is often called 'Romex' and is fairly easy to work with. If you don't have this type already, it is still the type you will most likely use for any upgrades. Originally, NM-B cable was all white, no matter what gauge of wire was inside of it. Now the jacket for the cable is color coded for the conductors that are inside of it, see 'Cable Colors' below.

Installing NM-B Cable

There are some restrictions for installing this type of cable. It is a flexible cable so it needs to be attached to something that provides support. It needs to have approved fasteners within a foot or less of a termination box and every four feet along an otherwise unsupported suface. Running a non metallic sheathed cable through the holes in wood studs counts as support.

NM cable is generally used for wood frame buildings. It cannot be used for metal studs without additonal protection. For wood studs the cable should be kept a minimum of 1 1/4" back from the edge of the stud. If this cannot be done, a metal protection plate needs to be installed.

UF-B

UF = Underground Feeder, B = Temperature Class (194 deg farenheight). This type of cable is a direct burial cable that can be used for outdoor and underground applications. The plastic jacketing is bonded to the wires, creating a tough cable that resists moiture and damage. You would normally use this wire in a wet environment and buried in the ground.

Installing UF-B Cable

MC Cable

MC = Metal Clad Cable, Temperature Class (194 Degrees farenheight). Similar to 'romex' or NM cable, this type can have multiple conductors of various gauges. It can also include a ground wire

AC Cable

NM-B Cable Color

White = 14 ga wire; Yellow = 

Orange

Gray

Black

Using Wire & Cable

The wire you need to use will depend on the situation. For outlets and lights you will use 14-2 or 12-2 w/Ground in most situations. Exceptionally long runs or high amperage devices may require heavier wire. Examples of this might be a sump pump, furnace or refrigerator.

Some 240 volt devices such as a hot water tank or electric base board heaters might use 12-2 or 10-2 w/Ground. Local codes, amps and distance will govern the correct wire size. Ranges and electric ovens require a lot more amps and are usually wired with 8-3 or 6-3 w/Ground. Appliances that are 240 volt but do not use as much amperage, like a dryer can be wired with 10-3 w/ground.

Remember, local codes govern and some areas require installations that are more stringent than national codes. Check with your local building inspector before beginning a project.

Purchasing Wire

Basic house wiring can involve several types of electrical circuits and wiring configurations. A few types of circuits you might normally find in a home are described below along with reasons why they might trip. Amperage of the breakers may vary. For special appliance circuits you will need to know the required amperage of the device.

Not sure if this is your problem? See the aricles 'Household Electrical Repair' and 'Residential Electrical Wiring' for more information and a listing of electrical topics.

Outlet circuits - Local codes and requirements will vary, but you will usually have between around six outlets on a single circuit. This number could be lower for circuits that are planned for appliances that use a lot of power. Kitchens, garages and workshops might be examples. These types of electrical circuits will include a 15 or 20 amp single pole breaker.

If this type of breaker trips, it is usually due to an overload. Too many devices are running at the same time. This will be especially true if you are running high wattage items, like heaters or fans. Try unplugging one item and reset the breaker. If it holds, try moving the item to an outlet on another circuit.

Lighting Circuits - Many homes are wired with the lights on separate circuits. You may have ten to fifteen lights wired to a single circuit. These circuits will usually be on a 15 amp single pole breaker.

Lighting circuits are not prone to being overloaded unless you have fixtures with auxiliray plugs in them. If you have a lighting circuit that continues to trip you will have to see if you have a short or a 'malfunctioning breaker'.

Room Circuits - Another method of laying out circuits would be to have an entire room on one circuit or two small rooms. This method can simplify the identification of breakers in the panel. The breaker type would likely be a 15 or 20 amp single pole.

Similar to outlet circuits, a room circuit breaker will likely trim when it is overloaded. Try shutting off one item at time and reseting the breaker to see what is causeing the problem.

Special Circuits - Certain appliances like a furnace or a refrigerator may be given dedicated circuits. The wiring would be for only the one device and the breaker would be sized per the requirements of the appliance. Dedicated circuits may also be installed for computer equipment.

240 Volt Circuits - Heavy duty appliances such as ranges, hot water tanks, air conditioners and dryers will require 240 volt dedicated circuits. These types of electrical circuits will have double pole breakers sized for the requirements of the device.

GFCI Circuits - Ground fault interrupters are a safety feature for outlets that are near any wet conditions. A special circuit with a GFCI protected breaker may be set up to cover the bathrooms, kitchens and outside receptacles. GFCI receptacles can also be used and may affect other outlets within the circuit they are installed in. GFCI circuits will be 15 or 20 amp single pole circuits.

This type of breaker is designed to prevent shocks from wet environments that can cause a device to ground out through a person. If any of the wiring gets wet it will trip the breaker. Remove the item that has gotten wet and do not plug it back in until it is thoroughly dry.

AFCI Circuits - Newer homes are equipped with arc fault circuit interupter breakers. These are designed to improve safety by preventing fires. They are more expensive and are wired differently that normal breakers. These are required in homes built since 2008 for many circuits in a home. These breakers have a test button, a neutral terminal and an extra wire that goes to the neutral bar. You will need to check with your local building department for arc fault requirements in your area.

Arc fault breakers can sense an 'arcing' occurance. A short in a wire will definately trim them. However, they are very sensitive and can at times be tripped by something as simple as plugging in a device. Try reseting the breaker after the item is plugged in. The breaker should hold, it is the arcing that trips it.

Summary

Do you have an electrical project you are working on? Some related articles are 'electrical repair', 'fixing outlet problems', 'wiring light fixtures', 'troubleshooting ceiling fans', 'wiring switches' and 'wiring three way switches'. Follow the links for more information.

This article gives you a brief overview of the different types of breakers in your home. We have also included what will cause them to trip. This will help you when you try and figure our why you are losing power.

The above is not a comprehensive listing of all the possible types of electrical circuits and combinations of electrical device. It does give you an idea of what you are likely to encounter.

Basic house wiring starts with your main service panel. This is where the main power comes into the house from the street. It is also the place where breakers need to be reset when they trip and the power goes off.

Not sure if this is your problem? See the articles 'Basic Residential Wiring' and 'Home Electrical Repair' for a listing of all the electrical topics.

Purpose of the Main Breaker Panel

Sometimes call a 'load center' or 'distribution panel', this is the nerve center of the homes electrical system.

At the top you will usually find a main breaker. I say breaker, but some houses still have fuse boxes. Fuse boxes are becoming less and less common. A main breaker may be anywhere from 50 amps to 200 amps for an all electric home.

Most new homes have between 100 and 200 amp services installed. The main breaker shuts off the power to the two bars that run down the center of the panel. These are the hot lugs of the panel. In one way or another, all the basic house wiring in your home involves these three wires.

How a Main Panel Works

Located along the sides you will find a ground bar and a neutral bar. The neutral bar is connected to the main neutral wire coming into your home. You will normally hook white and sometimes bare ground wires into this bar. The ground bar as the name implies is hooked to grounding wire that is attached to a ground rod or sometimes a copper plumbing pipe. Note: Attaching a ground wire to a plumbing pipe does not meet code in most places.

Black, red and sometimes white wires are hooked to the individual breakers, depending on the type of circuit. The breaker interrupts the hot wire, similar to what a light switch does. Some breakers are two pole, providing 240 volt current for heavy duty appliances. Every other breaker, as you move vertically down one side is hooked the same hot side. Thus a two pole breaker picks up power from both sides of the panel.

Installing a new panel is a pretty big job and will usually be left up to the professionals. Not impossible for a homeowner, but it you will need to read more than one article about basic house wiring before you tackle it. Unless of course, you cousin is an electrician, then you are good to go. Adding a circuit may be something you would consider tackling.

Safety Concerns

Do not work in the panel without shutting off the main breaker. Even then you still have power in the top of it. Don't have a main breaker? Then you will probably have a disconnect below the meter. Essentially the same as main breaker, just in a different location.

See the article 'Electrical Safety at Home' for tips on what to do to prevent shocks and injuries when working with electricity.

Common Main Panel Repairs

Tripped Breakers

Without a doubt this is the main reason you will be interested in the main panel. Whenever you lose power to an area of the house, the 'breaker panel' is the first place that you go.

A tripped breaker is easily identified. It will be at about the mid point between fully on and off. You have to switch the breaker to off and then turn it back to the on position.

Replacing Breakers

Circuit breakers can go bad. If one keeps tripping when there is no extra load on it and no short, then it is likely not working properly. You need to get the correct breaker for a replacement.

See the article 'Replacing Circuit Breakers' for instructions on how to replace one.

Adding Breakers

Adding a circuit breaker usually means adding a circuit. A new circuit mean more electrical devices and the associated wiring. This is a bigger job that may be prohibitive for more than one reason.

First would be the wiring. Would you have access to run the wiring. This might not be a problem in an attic, basement or garage. But in areas that are already finished it can be a big problem.

If you are able to run the new wiring, you may be able to add a new circuit. See the article 'Adding New Circuit Breakers' for more information and instructions on what to do.