About The Electrical Service Panel
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Service Panel
Hey, this is Jon with Two Moose Home Inspections and today we will be talking about your electrical service panel and what you need to know… welcome to inspector insights
This 6-part video series will be discussing the Service Entrance Panel, Fuses, Circuit Breakers, Ground Fault Circuit Interrupters, Arc Fault Circuit Interrupters, and Whole Home Surge Protection. This video specifically will be discussing the service entrance panel, (Confusion) or service panel, breaker box, load center, panel board, fuse box… well lets just call it a service panel.
Inside the service panel the electricity is divided into circuits which can be thought of as loops. These loops or circuits may go out to a room, loop around the room, and then come back. Some electrical systems will have one circuit for the whole room such as the “Laundry Room,” others will have separate circuits for the lights and the power receptacles. Separating the lights from power receptacles will reduce the likelihood of lights briefly dimming when an appliance such as a laundry machine first kicks on. Home theater enthusiasts will frequently have dedicated electrical circuits for audio equipment, video equipment and their lighting which helps to ensure that all of their professional equipment gets the “cleanest” power that it can without voltage drop or brown outs as components are being turned on.
The benefit of having smaller circuits instead of one large circuit is that repairs can be done more safely and more easily. When an electrical issue occurs in a room with a dedicated circuit an electrician can more quickly diagnose the localized issues because they are not looking all over the house for the problem
So where is your service panel. Service panels can be located anywhere in the house. Garages, Hallways, behind doors, and on the exterior of the home are all common locations, but we have also found service panels in closets, bathrooms, behind appliances, and covered by wall art. There are many specifications about where service panels are and are not allowed to be, but we can save that for a different video.
Service panels are made of sheet metal and normally come in grey or white. Although they are not supposed to be painted that simple fire safety precaution hasn’t stopped anyone. When properly installed the service panel is grounded and doesn’t pose a risk to anyone, but if the cover is missing or incomplete live electrical conductors can be exposed to touch which could result in serious injury or death. I can’t stress this enough, don’t mess around with electricity.
Some houses have multiple service panels which would be referred to as Sub Panels. The service entrance panel is where the electrical supply enters and is then distributed throughout the house, and the subpanel may be one on of the distributed locations. Some houses have a service panel for the house and a sub panel for the garage or workshop. This is because the workshop might have a need for multiple circuits for lights, receptacles, specialty equipment, and so one. You will also see sub panels in condos. The Condo building will have a main electrical distribution room that can control each unit when repairs need to be made and each condo unit will have a dedicated sub panel just for that unit. The only difference between a service panel and sub panel is that a service panel supplies the sub panel, and the sub panel must have an isolated neutral bar and dedicated ground bar whereas the service panel’s neutral bar is grounded to earth.
So, what is a neutral bar, glad you asked, let’s take a detailed look at a service panel.
Most service panels are 14 inches wide so they can fit between wall studs that are normally set 16” on center. The panel is made of metal, it can be located indoors or outdoors, and its purpose is to protect you from making contact with energized parts.
The cover is referred to as the dead front and if installed correctly you shouldn’t be able to touch the electrical conductors in side the panel, but far too often holes are left in the cover and not filled with a filler plate. There are two potentially deadly issues that can be resolved for less than $1 dollar. They are filler plates that fill the open spaces in the panel cover and using the appropriate blunt nose screws. Far too often people use regular screws which can cut into the electrified wires. Please stop trying to kill our inspectors and spend the extra dollar to keep you and our inspectors safe.
Next up is the main device, this can be a main breaker or a main lug. A main breaker allows the user to turn off all the power to the panel using the main breaker and it also protects the wires coming from the supply to the house. Main lug only is just what the name implies, it is a lug only. The electrical disconnect is located elsewhere and this is 100% acceptable.
The bus bar is an extension of the incoming power and is where the breakers attach to allow power distribution to the circuits. Normally there are two bus bars that each supply 120v which means that you can use both to get a total of 240 volts for large appliances such as electric ranges, and clothes dryers. Some service panels allow the use of twin breakers, but you must check the information placard to make sure your panel can accept them.
The Neutral bar is where the neutral wires go. Think of the circuit has having a positive and negative or a hot and neutral. To simplify this concept, think of the neutral bar as where the energy “comes back to.” There can only be one neutral wire installed per hole on the neutral bar because that is only correct path for the hot electricity to return to the neutral and the connection must be perfect.
The ground bar is where the ground wires go. Think of this as your electrical safety path if something goes wrong with the hot and neutral. You can have up to 3 ground wires per hole because all ground wires are all paths back to ground.
That pretty much wraps up our discussion about the service panel, but we still have to talk about fuses, circuit breakers, ground fault circuit interrupters, arc fault circuit interrupters, and surge protection. The next video will be discussing fuses and why we don’t use them anymore.
Thanks for watching, if you have any questions or if you would like to schedule a home inspection, please visit Two Moose Home Inspections .com. Have a wonderful day.
Fuse
Hey, this is Jon with Two Moose Home Inspections and today we will be talking about fuses and why your electrical system might be outdated if you have them, welcome to inspector insights
This 6-part video series will be discussing the Service Entrance Panel, Fuses, Circuit Breakers, Ground Fault Circuit Interrupters, Arc Fault Circuit Interrupters, and Whole Home Surge Protection. This video specifically will be discussing fuses.
Let’s get one thing clear. Fuses are not designed to protect you; they are designed to protect the wires in your walls. A fuse will not save you if you are being slowly electrocuted, but hopefully a fuse will save you by preventing your house from burning down by making the ultimate sacrifice.
Fuses are by nature sacrificial. They are designed to be used once and then replaced. Thomas Edison first made fuses back in 1890 and houses were commonly wired with fuses until the 1960’s. If you house still uses fuses, then your electrical system might be over 50 years old.
Household fuses have an Edison base which means they have the same style base as a lightbulb. The fuse would be screwed into the circuit and if the circuit were ever overloaded the sacrificial metal element inside the fuse would melt or burn before the wires in your walls had a chance to do the same. Have you ever seen the wires inside of a toaster? That is what can happen in your walls if your electrical system is overloaded without a fuse or circuit breaker. This can happen if you have too many electronic devices plugged into a circuit, think about the mess of wires behind your TV.
When the sacrificial element burns up the circuit is effectively disconnected, and the power is shut off saving your house from catching on fire. If you want to restore power to that circuit, you will have to replace the fuse, but what if you no longer have the right size fuse because they just keep burning up when you try to use 2 hair dryers at once because you’re running late? Well…. That is where the problems with fuses start to show themselves.
Let’s say you had a 15-amp fuse because the wires in your walls are designed not to catch fire with 15 amps of current passing through them, but you ran out of 15-amp fuses, and you only have 20-amp fuses. Well…. Since the fuse is designed to be replaced by the homeowner, they could easily put a fuse that was larger than intended into the circuit. This issue was very common and often resulted in fire, but sometimes the homeowner was lucky and although the wire was only designed not to catch fire at 15 amps it miraculously also didn’t catch fire at 20 amps, however the home owner has run out of both 15 amp and 20 amp fuses, but the homeowner might just have a fix for that pesky piece of sacrificial metal in the fuse keeps burning out.
A shockingly common practice to overcome those pesky “nuisance trips” would involve a homeowner and a coin. Homeowners have been known to stick a coin inside the fuse box to bypass the fuse altogether this obviously left many houses in a pile of ash as the wires in the walls would overheat and catch the house on fire.
In addition to being able to stick coins in the fuse box many people also stuck their fingers in the fuse box and contacted live electrical conductors with varying results.
Because the fuses were so bulky many houses had less circuits in the house which could result in more opportunity for overloading and made diagnosing issues much more difficult.
There have been some advancements to fuse boxes which include circuit breakers made in the Edison base form factor, however these circuit breakers had a nasty habit of not shutting off the power during a fault when the fuse box door was closed because well…. The circuit breaker crammed in a fuses body was too large for most fuse boxes and when the fuse box door was shut the door would rest on the reset switch which bypassed the fuse’s protections… and you guessed it… the house would catch on fire.
In general, it is a good practice although no one does it to replace your service panel every 20-30 years. This is to ensure that the electrical protection devices meet current safety standards and to help catch issues with corrosion or arching that may have been occurring unnoticed before it is too late. So, if you have a fuse box, it is time to hire an electrician and get it replaced.
The next video will be discussing the circuit breaker which will then lead us into ground fault circuit interrupters and arc fault circuit interrupters.
Thanks for watching, if you have any questions or if you would like to schedule a home inspection, please visit Two Moose Home Inspections .com. Have a wonderful day.
Circuit Breaker
Hey, this is Jon with Two Moose Home Inspections and today we will be talking about your circuit breakers and how they are not designed to safe you from electrical shock. Welcome to inspector insights
This 6-part video series will be discussing the Service Entrance Panel, Fuses, Circuit Breakers, Ground Fault Circuit Interrupters, Arc Fault Circuit Interrupters, and Whole Home Surge Protection. This video specifically will be discussing circuit breakers.
In the previous video we discussed fuses and how they are designed to be replaced by the homeowner and how that resulted in numerous house fires. So, let’s keep things clear just like we did last time. Fuses and Circuit breakers are not designed to save you from electrical shock… their only function is to protect the wires in the walls from being overloaded which would result in them overheating and catching your house on fire. Think of the wires in your toaster as they heat up… but inside your walls.
Circuit breakers outperform fuses in many ways. Circuit breakers are reusable. If the breaker is tripped the homeowner can reset the breaker in the same way that a homeowner would flip a switch to turn the lights on. The homeowner should not be exposed to any electrified conductors, and the homeowner can’t accidently put in the wrong sized breaker… or bypass the breaker with a coin.
Circuit breakers are shrouded with secrecy much the same way the wizard of Oz was behind the curtain. The hidden inner workings of a service panel help to keep people out of the service panel because the effort it takes to remove the dead front cover is a reminder that only an electrician should be working inside the panel, and because not knowing what is behind the panel is a little bit scary so people don’t mess around with their house’s electrical components as often.
In the service panel video, we already talked about the internal components of a service panel, so let’s talk about a circuit breaker and what makes it work.
Another name for a common circuit breaker is a thermal magnetic breaker. If we look at the parts of its name then we know that it is a breaker, so it will break the electrical circuit thus stopping the flow of power and that the breaker can do this in one of two ways either a thermal trip or a magnetic trip. Hence being a thermal magnetic breaker.
Circuit breakers use a bi-metallic strip to trip the breaker when the electrical current is greater than the breaker’s rating. One hair dryer alone can draw 15 amps of power, so if you are running two hair dryers on a 15-amp circuit the circuit will trip. As the hair dryers are heating up so is the bi-metallic strip. As the bi-metallic strip is heated the strip will deform causing the breaker to switch off. This is a thermal reaction to the overcurrent.
If there is short in the circuit meaning that electricity can flow through the circuit with very little resistance the breaker will trip. When the short circuit happens the massive increase of current will induce a magnetic field inside the circuit breaker causing the breaker to switch off. This is a magnetic reaction to the short circuit.
Circuit breakers are able to protect the electrical wiring in your walls from overheating due overloading even if it happens slowly or all of a sudden, and each circuit in the service panel is protected by a breaker that has an amperage rating printed on it. This amperage rating is determined by the thickness or gauge of the wire that was installed for the circuit.
A common question that we get happens right after people see a dozen 15-amp breakers in a 100-amp panel. People ask how 180 amps of power can be safely drawn through a 100-amp service panel, and the answer is that it can’t. However, keep in mind that the 15-amp breaker is designed to protect the wire in that circuit from a load greater than 15 amps, and the 100-amp main breaker for the service panel is designed to protect the wire from a total load of no more than 100 amps.
In practice what this means that your new LED lights on the 15-amp breaker might only be asking for 5 amps and just because the breaker is designed to handle 15 amps it doesn’t mean that the circuit will be drawing its maximum of 15 amps, now, or at any time during its service life. And the 100amp breaker will trip if the total amperage being drawn by those dozen circuits exceeds 100amps.
There are a lot of improvements that circuit breakers bring to the home compared to fuses, but the still lack that special something. Neither fuses nor circuit breakers are designed to protect you from being electrocuted, but our next video will discuss the Ground Fault circuit interrupter which is designed to do just that.
Thanks for watching, if you have any questions or if you would like to schedule a home inspection, please visit Two Moose Home Inspections .com. Have a wonderful day.
GFCI
Hey, this is Jon with Two Moose Home Inspections and today we will be talking about your Ground Fault Circuit Interrupters and how they might save your life without you even knowing it. Welcome to inspector insights
This 6-part video series will be discussing the Service Entrance Panel, Fuses, Circuit Breakers, Ground Fault Circuit Interrupters, Arc Fault Circuit Interrupters, and Whole Home Surge Protection. This video specifically will be discussing Ground Fault circuit interrupting circuit breakers which can be referred to as GFI’s or GFCI’s.
So, let’s talk about what a GFCI is and why it exists. As we learned in the previous video Circuit Breakers can trip with a slow overcurrent such as running to many devices on a circuit or when a fast short circuit occurs. A short circuit occurs when the hot wire and neutral wire are connected to each other without any resistance.
Let’s say you’re about to hang your recently commissioned oil painting of yourself on the wall of your man cave or she shed and as you accidently hammer the anchoring nail through the hot and neutral wires, the energy will quickly travel through the nail without resistance and the result would be a short circuit which would most likely trip the circuit breaker. You were not hurt when this happened because energy wants to follow through the path of least resistance back to the source, and that path of least resistance was from the hot wire through the nail and into the neutral wire. Hopefully, the circuit breaker tripped, and your walls are not catching on fire, but maybe not… spoiler alert this is where an Arc Fault Circuit Interrupter would be really handy, but we aren’t there yet.
So, what does a GFCI do for you? Let’s say you only drove the nail into the hot wire and not both wires. This would electrify the nail, but not create a short circuit that would trip the circuit breaker. If you were to touch the nail as you hang your panting you could receive an electrical shock that could result in electrocution. If you’re unfamiliar with the difference between shock and electrocution, the difference is that you can tell people you have been shocked, but you won’t be able to tell anyone that you have been electrocuted. Because your dead….
So how do we safeguard ourselves? A good place to start is by installing GFCI breakers at the service panel. A GFCI is made of a circuit board and an electromechanical switch that is controlled by a solenoid. The GFCI is constantly monitoring the amount of electricity that is going out on the hot wire and returning on the neutral wire. The values should always be the same, but if more electricity is going out of the circuit compared to what is coming back then the GFCI will disconnect the power immediately because it has sensed that power is going is going elsewhere. And where is elsewhere? The electricity could be flowing through a person, discharging into an appliance, or lost in some other way because of a damaged circuit.
In addition to sensing a difference between hot and neutral, GFCI’s have another sensor on their circuit board that senses ground to neutral current which means that GFCI outlets can be used to replaced two prong outlets in older homes allowing the homeowner to safely use appliances with a dedicated ground plug.
It is easy to understand the way that a GFCI can save your life if you stick a fork in an outlet since the electricity would be flowing from hot, through the fork, into you, and then through the floor. The neutral wire would not have any current, and the GFCI would cut power to the outlet. Understanding the Ground to Neutral fault when the GFCI is used to replace a 2-prong wall outlet that doesn’t have a dedicated ground wire can be a little more difficult to explain, but we will try. In a large metal appliance like a washing machine the hot and neutral wire are insulated from the metal frame of the washer, and the metal frame of the washer is grounded to the grounding wire. If the hot wire were to make contact with the metal frame of the washing machine, then the electricity would travel back through the grounding wire, keeping the occupants of the home safe. The occupants may feel a slight electrical sensation when they touch the appliance, but the majority of the electricity should be flowing over the ground wire and not through the homeowner. Since the two prong outlet doesn’t have a ground wire the amount of power returning to the GFCI is the same that went out, so that hasn’t caused a Hot Neutral fault, but the GFCI is able to differentiate power returning on the ground and because the power is returning on the ground there is a ground to neutral fault and the GFCI will trip turning off the power and protecting the user.
GFCI’s can be installed in circuit breakers or in electrical receptacles. It is common to see GFCI receptacles in bathrooms, kitchens, laundry rooms, garages, the exterior of the house, or anywhere that water might be found. If you touch a hot electrical conductor wearing well insulated shoes on a dry surface you might not be seriously hurt, but if are standing on a surface that has water on it such as your garage when snow melts off your car or even just standing on the concrete floor with sweaty socks you have given the electricity a path to flow back to the source through your body, which will result in injury.
The standards for GFCI’s are always improving, but at this point almost every surface that could have liquid spilled on it should be protected by a GFCI. Even a bar that doesn’t have a sink could have a drink spilled on it which could come in contact with some Christmas lights, so the bar should have a GFCI installed.
The nice thing about using a GFCI circuit breaker combo inside the Service panel is that the GFCI breaker will protect the entire circuit from when it leaves the service panel as hot wire to when it returns as a neutral. This can protect not just the outlets in the room, but the wires in the walls and the lights above your head. This extra layer of protection is inexpensive and a true-life saver.
GFCI protection is just the start of what you can do with your service panel. We still have yet to cover Arc fault circuit interrupters and whole house surge protection. And if you remember that nail we drove through the wall earlier, that might still be causing an issue that only an AFCI can manage, so let’s talk about that in the next video.
Thanks for watching, if you have any questions or if you would like to schedule a home inspection, please visit Two Moose Home Inspections .com. Have a wonderful day.
AFCI
Hey, this is Jon with Two Moose Home Inspections and today we will be talking about Arc fault circuit interrupters and how they might soon be protecting every circuit in your home. Welcome to inspector insights
This 6-part video series will be discussing the Service Entrance Panel, Fuses, Circuit Breakers, Ground Fault Circuit Interrupters, Arc Fault Circuit Interrupters, and Whole Home Surge Protection. This video specifically will be discussing Arc Fault circuit interrupters.
Much like the GFCI breakers that we learned about in the previous video AFCI breakers use a circuit board to detect faults and shut off power before your house has a bad outcome. If you remember the scenario that we discussed about you recently receiving that commissioned oil painting of yourself and using a nail to hang it up, well… I illuded to the need for AFCI protection and here is why.
If that nail of yours ever so barely nicked the hot wire it is possible that a little bit of stray electricity is arcing between the wire and the nail. An electrical arc is extremely hot, so hot in fact that it turns the air between the conductors into plasma which is very very hot. When the nail was hammered into the wall there was no indication that you hit the wire, nothing stopped working, you were not injured and everything seemed ok, except that the arcing electricity will soon catch your house on fire. Thanks to the AFCI breaker installed in your service panel the breaker detected the fault and shut off the power thus saving your house.
An AFCI looks at the frequency of the current traveling through the wires and if it detects a specific frequency then it will classify that as a fault and trip the breaker. Good arcs can occur when a light switch is operated, a refrigerator compressor turns on, or when a microwave is used. When a bad arc event occurs, it produces a broad range of frequencies, so the AFCI is calibrated to ignore good arcs and only classify the frequencies of bad arcs as a fault. A significant amount of research and improvement has been done to classify good arcs to prevent nuisance trips. These nuisance trips were a real inconvenience when AFCI’s were first produced, but they have all but been eliminated in modern AFCI breakers.
Combination breakers can include protections from AFCI’s, GFCI’s, and Thermal Magnetic Breakers. Modern Combination AFCI breakers can detect 7 different types of faults conditions making them the best safety product that you can buy to update your electrical system. This is why in the very near future combo AFCI’s will be required to protect every circuit in a home for new construction or electrical upgrades.
I can already hear it…
Woah their buddy, my house has been grandfathered in and I don’t want any of that new fangled technology in my house.
And I get it. You’ve been grandfathered in, and you have every right to drive a vintage car without airbags, crumple zones, or seatbelts going 75 mph down the highway, and you know what… if you want to keep playing with your vintage lawn darts set when the whole family comes over to visit, more power to ya.
But, keep in mind, just because you have been grand fathered into the future, doesn’t mean you shouldn’t make a change to keep you and your family safe for generations to come.
In the next video we will be talking about how to keep your electronics safe.
Thanks for watching, if you have any questions or if you would like to schedule a home inspection, please visit Two Moose Home Inspections .com. Have a wonderful day.
Surge Protection
Hey, this is Jon with Two Moose Home Inspections and today we will be talking about whole house surge protection and how you might still want to keep your power strip surge protectors. Welcome to inspector insights
This 6-part video series will be discussing the Service Entrance Panel, Fuses, Circuit Breakers, Ground Fault Circuit Interrupters, Arc Fault Circuit Interrupters, and Whole Home Surge Protection. This video is the last in the series and we will be wrapping this series up with whole home surge protection.
It is very likely that you have plugged you TV and Stereo into a power strip that had surge protection, but how does that little power strip protect your TV from a lightning strike?
Most surge protectors use a Metal Oxide Varistor or MOV for short. An MOV is a voltage dependent resistor which means that their resistance varies depending on how much voltage is applied. Think of a MOV as a bypass that only opens with high voltage. When voltage stays below the MOV’s rating they have such high resistance that the bypass is effectively closed which is good. When the voltage is dramatically increased during an event such as a lighting strike the MOV’s resistance I effectively nonexistent meaning that the bypass is wide open for all of that extra voltage to bypass sensitive electrical components thus protecting your TV and stereo from being damaged.
MOV’s can be damaged by surges and some surge protectors have an indicator light to warn the user that the surge protector is no longer working and needs to be replaced. But in addition to protecting your electronics from large surges did you know that some surge protectors can use the MOV’s as high frequency filters which can remove noise from the electricity going to your expensive devices? “Clean power” is nothing new in the computing and home theater world but make sure to do your best to educate yourself on the processes that these companies use so you don’t find yourself buying snake oil.
Although the power strip is synonymous with surge protection you can also get whole house surge protection by installing one device in your service panel. An electrician can install a whole house surge protector that can protect every circuit in the house. That means the whole house surge protector will take the hit if your house is struck by lighting not only saving your TV and stereo, but also your appliances, lights, and any other electrical devices in your house.
Although a whole house surge protector is all that you need to protect every electrical device in your house it is still a good idea to have a dedicated surge protected power strip for sensitive electronics like TV’s, stereos, and computers. Not just to clean the power before it gets to the device but because a whole house surge protector can only help protect your devices from a surge that originates outside of your house, not from something that originates inside your house like spilling coffee all over your vintage vinyl record collection and amplifier…. You know who you are.
Anyway…
Thanks for watching, if you have any questions or if you would like to schedule a home inspection, please visit Two Moose Home Inspections .com. Have a wonderful day.