The 6 Parts of Your Circuit Panel
The circuit panel is the hub of your whole home electrical wiring system. Now that we have learned safety, let's take a look at the main component of household electrical service - the circuit breaker panel.
The Components Inside Your Circuit Panel...& What They Do.
1. This is what your circuit panel looks like.
Most panels will look something like the one shown in the image to our left. This is essentially a meeting spot where either excess current leaves your house (through the neutral/ground bus) or where current is distributed (through the main service, and each individual circuit breaker controlling an individual circuit.)
For those of us who do not know, the 'hot' wire is the wire that contains the current. The neutral wire is the wire that will bring back any excess current and send it safely to ground. The neutral wire (white wire) is very closely related to the bare or green sheathed wire you'll see in any 120+ volt system which is called the ground wire. The ground was designed as a pathway for electrical current to go into the Earth via a ground rod as a means of electrical safety under ground fault conditions.
For those of us who do not know, the 'hot' wire is the wire that contains the current. The neutral wire is the wire that will bring back any excess current and send it safely to ground. The neutral wire (white wire) is very closely related to the bare or green sheathed wire you'll see in any 120+ volt system which is called the ground wire. The ground was designed as a pathway for electrical current to go into the Earth via a ground rod as a means of electrical safety under ground fault conditions.
2. After you have turned off the main power (if allowable), next you will want to remove the panel cover screws in order to gain entry inside your panel.
IMPORTANT If you were in such a situation where you were allowed to turn off the main power, the electricity is flowing through one side of the main breaker. It should not be hot on the bus, but always check with your multimeter first before doing anything else.
If you were not able to turn off your main power, keep in mind that the panel bus bars are hot and extremely dangerous. All it takes is 5 milliamps to electrocute someone so whatever you do, make sure to stay as far away as possible from the main busses inside a 120 - 240 V residential circuit breaker panel. The buss bars will be on both sides of the panel which is actually touching the breaker. (We'll cover this a little bit more coming up.)
If you were not able to turn off your main power, keep in mind that the panel bus bars are hot and extremely dangerous. All it takes is 5 milliamps to electrocute someone so whatever you do, make sure to stay as far away as possible from the main busses inside a 120 - 240 V residential circuit breaker panel. The buss bars will be on both sides of the panel which is actually touching the breaker. (We'll cover this a little bit more coming up.)
3. This is what your ground bar should appear as when you open your cover to your circuit breaker panel.
As a beforehand warning, your ground bar may or may not have the neutral (white) wires attached to it. The ground bar is a tiny bar, about the size of a ball point pen, with a bunch of screws tapped through it. Most ground bars are made of zinc coated copper, although some are completely aluminum. The ground bar is easy to take out of the panel box itself, as it is only held on by a few 10-32 or 10-24 sized screws. You may have more than one ground bar inside your box when you inspect it upon removing the panel cover.
4. The neutral bar
As already mentioned, in a lot of areas of the country the ground and neutral bar are all attched on the same bus (or bar). But, it is correct when the ground wire from the ground bar goes straight to a designated neutral bar (if you have one inside your box). 9 times out of 10, it will be a hodge-podge of bare copper wires and neutral wires all co-mingling on the same bus(ses) or bar(s). Usually this happens as the house gets older and older. As limited space on certain bus bars is taken, most post-house construction contractors (retro fitters) will place a neutral or a ground on whatever bus is available. Sometimes you will even see two wires occupying one slot. These configurations are not optimal as an inspector will possibly fail the contractor (or you) with ground wires on the neutral bus (and vice versa).
5. The Main Breaker: A Switch Inbetween The Service & Every Circuit In Your House Inside That Panel.
A circuit breaker is nothing but a single pole switch (most of the time). It's sole purpose is to act as a barrier inbetween the electricity being supplied by the outside source (ie power company, solar panel, wind generator, generator, etc.) and the circuits inside your house. The mission of a breaker is to trip once a certain, predetermined amount of current has passed through it all at once. Although some breakers may have different names (ie arc-fault, ground fault, main, etc) and some are made by different manufacturers (ie Siemens, GE, etc) every breaker is simply a safety switch. With the main breaker shown in the picture, it depicts a 240 Volt, 100 amp breaker. This means that this breaker is only capable of supplying 24,000 Watts of power (Power = Volts X Amps). This is fairly common in houses nowadays, although you do see a lot of 150 Amp breakers too, especially in larger houses, such as the one you would find in a posh area such as Loudoun County.
6. The Circuit Breakers Themselves...
Like we said above, breakers come in many different sizes, shapes and forms. We'll start off with one of the most basic you'll find in a house inside Loudoun County at the time of this writing - the 15 amp 120 Volt breaker. If you look all the way to the bottom right-hand side of this picture, you'll see a 15 amp, 120 V breaker. These breakers are usually meant for common areas that will have a high unlikelihood of getting wet by any type of water (from a bathroom, for instance). Directly above our 120V, 15 amp breaker is a 240V 20 amp breaker. As you can see, this breaker is twice the size of the 120V, 15 amp competitor. The reason for this is because it has to touch both of the phase bus bars which holds the current responsible for your home. Some 240V breakers you can turn off individually, while others you are only allowed to turn them off all at once (such as the breaker shown to the left of the 240V, 20 amp breaker we have just used as an example). All of the various shapes, sizes and forms of breakers are meant to supply the right amount of current to a device or prevent injury to you (or whomever) in the event of an electrical fault.
As a final word of advice, it is highly recommended that you do not go inside a live circuit breaker box ever. The potential for extreme bodily harm is too great to you and those around you. The best advice to follow is to hire a professional electrician to assure that the problem is located and solved, and to keep you alive and intact for your loved ones.
As a final word of advice, it is highly recommended that you do not go inside a live circuit breaker box ever. The potential for extreme bodily harm is too great to you and those around you. The best advice to follow is to hire a professional electrician to assure that the problem is located and solved, and to keep you alive and intact for your loved ones.