A Safe Understanding Of New Electric Circuits Wiring

Calculating Electrical Load Capacity for a Home

The term “electrical load capacity” refers to the total amount of power provided by the main service for use by your home’s branch circuits and the lights, outlets, and appliances connected to them. Understanding capacity and load becomes necessary if you are planning the electrical service for a new home, or if you are considering an electrical service upgrade to an older home. Understanding the load needs will let you choose an electrical service with an appropriate capacity. In older homes, it’s extremely common for the existing service to be badly undersized for the needs of all the modern appliances and features now in use.

Total electrical capacity of an electrical service is measured in amperage (amps). In very old homes with knob-and-tube wiring and screw-in fuses, you may find the original electrical service delivers 30 amps. Slightly newer homes (built before 1960) may have 60-amp service. In many homes built after 1960 (or upgraded older homes), 100 amps is the standard service size. But in large, newer homes, 200-amp service is now as a minimum, and at the very top end, you may see 400-amp electrical service installed.

Understanding Electrical Capacity

Calculating how much power your home needs is a matter of calculating the amperage load of all the various appliances and fixtures, then building in a margin of safety. Generally, it’s recommended that the load never exceeds 80 percent of the electrical service’s capacity.

To use the math, you need to understand the relationship between watts, volts, and amps. These three common electrical terms have a mathematical relationship that can be expressed in a couple of different ways:

Volts x Amps = Watts

Amps = Watts/ volts

Calculating Load

After you know the capacity of individual circuits and of the home’s full electrical service, you can then compare this with the load, which you can calculate simply by adding up the wattage ratings of all the various fixtures and appliances that will be drawing power at the same time.

 

Breaker Box Safety: How to Connect a New Circuit

We believe in safe DIY. That’s why we’ve always been reluctant to show readers how to open a breaker box and connect a new circuit. Even with the power shut off, there’s a chance you could touch the wrong parts and kill yourself. But then we figured if we didn’t show you, you’d just go search the internet. And that scared us even more. So we’re going to walk you through the process, showing you the safest way to open the breaker box, wire a new breaker and test your work.

Opening the main circuit breaker panel box and adding a circuit is actually pretty easy. You only have to connect three wires to add a circuit, and each circuit wire is color-coded. But there are some safety precautions, and if you ignore them, you could kill yourself. Really. If you follow our safety steps in order and to the letter, you’ll be fine. But if at any point you’re unsure how to proceed or feel uncomfortable with the project, call an electrician.

Get the right parts and tools

Before you go shopping, open the door of your breaker box and copy the manufacturer’s name, the box model number, and the style numbers of the breakers that are approved for your box. Then buy one of those breakers. If your home center doesn’t sell the right model or brand, you’ll have to go to an electrical supplier. You cannot install a circuit breaker style that isn’t specifically approved for use in your box—even if it fits inside the box. While at the store, pick up a few 1/2-in. plastic snap-in cable clamps to secure the new cable. They’re safer than metal clamps because you don’t put your hand in the panel to install them

Power down, then remove the cover

Turn off all computers in the house before you switch off the power. Then switch off the main breaker (the service disconnect) and follow the panel box cover removal procedure shown in the photo

Test to make sure it’s dead

It’s dangerous to assume the power is really off just because you’ve flipped the service disconnect to the off position. There’s a slim chance that the service disconnect didn’t work properly, keeping power to some breakers. So test each and every breaker to make sure it’s really dead. If the test light lights up, stop and call an electrician.

 

Preventing Electrical Overloads

Understanding Electrical Overloads

Every December, the neighbor across the street lights up the block with an elaborate holiday light display. Four-foot plastic angels stand in ranks, 3-ft. candles dot the landscape, elves pop out from behind plastic snow figures, and Santa in his loaded sleigh skims across the roof with a cluster of reindeer

But every year dozens of outdoor light displays like this unexpectedly go out. You might have plugged in a small electric heater and turned it on to warm your feet. Or switched on a hair dryer. Or dropped a snack into the toaster. It’s not only the outdoor display that goes out, but perhaps most of the main floor lights too. The TV in the family room quits. The clock in the kitchen stops. And later an electrician tells you that the refrigerator stopped running too.

The problem? An overloaded circuit. The power needed by the outdoor lights added to the load from the refrigerator, the heater and any other devices connected to the same circuit, and all of them running at once exceeded the capacity of the electrical wiring

Figure A: Circuit With an Overload

An electrical circuit with too many electrical devices turned on can exceed the circuit limit. Circuit breakers or fuses will automatically shut off the circuit at the main panel.

Circuit logic

The nerve center of your electrical system is the main panel, usually a gray metal box about the size of a cookie sheet, that typically sits in some obscure spot in a utility room, the garage or the basement. Three large wires from the utility company feed the main panel. Although you might spot the wires outside if they’re overhead, they’ll be encased in conduit inside for safety, because they contain virtually unlimited electrical power.

 

Electric circuit

Electric circuit, path for transmitting electric current. An electric circuit includes a device that gives energy to the charged particles constituting the current, such as a battery or a generator; devices that use current, such as lamps, electric motors, or computers; and the connecting wires or transmission lines. Two of the basic laws that mathematically describe the performance of electric circuits are Ohm’s law and Kirchhoff’s rules.

Electric circuits are classified in several ways. A direct-current circuit carries current that flows only in one direction. An alternating-current circuit carries current that pulsates back and forth many times each second, as in most household circuits. (For a more-detailed discussion of direct- and alternating-current circuits,

The network of transistors, transformers, capacitors, connecting wires, and other electronic components within a single device such as a radio is also an electric circuit. Such complex circuits may be made up of one or more branches in combinations of series and series-parallel arrangements.

 

Electric circuits

Student everyday experiences

Students have plenty of experience using everyday household appliances that rely on electric circuits for their operation ( torches, mobile phones, iPods). They very likely have developed a sense that you need a battery or power switch to be turned on to make things ‘work’, and that batteries can go ‘flat’. They tend to think of electric circuits as involving something they call ‘current’ or ‘energy’ or ‘electricity’ or ‘voltage’, all labels which they often use interchangeably. This is unsurprising given that all these labels are frequently used in everyday language with unclear meaning. Whichever label students use, they are likely to see electric circuits as involving ‘flow’ and something being ‘stored’, ‘used up’, or both. Some everyday language, for example about ‘charging batteries,’ may also be a source of conceptual confusion for students.

Specifically, students often see current as being the same as voltage, and think current can be stored in a battery, and that current may be used up or transformed into a form of energy, like light or heat.

‘the unipolar model’ – the view that only one wire is actually needed between the battery and the light bulb for there to be a current in the circuit.

‘the clashing currents model’ – the view that current ‘flows’ from both terminals of the battery and ‘clashes’ in the light bulb.

‘the current consumed model’ – the view that current is ‘used up’ as it ‘goes around’ the circuit so the current ‘flowing towards’ the light bulb is greater than the current ‘flowing away’ from it back to the battery.

Must Know How To Use New Electric Circuits

CIRCUIT SCIENCE PROJECTS

Build a Circuit

How to make a circuit? A circuit is a path that electricity flows along. It starts at a power source, like a battery, and flows through a wire to a light bulb or other object and back to other side of the power source. You can build your own circuit and see how it works with this project

Insulator or Conductor?

Materials that electricity can flow through are call conductors. Materials that stop electricity from flowing are called insulators.

Before you test each object, guess whether it will make the light bulb light up or not. If it does, the object you’re touching the wires to is a conductor.

The light bulb lights up because the conductor completes, or closes, the circuit and electricity can flow from the battery to the light bulb and back to the battery! If it doesn’t light up, the object is an insulator and it stops the flow of electricity, just like an open circuit does.

 

How to Make a Simple Electrical Circuit

Gather the necessary materials.

To build a simple circuit, you will need a power source, 2 insulated wires, a light bulb, and a light bulb holder. A power source can be any type of battery or battery pack. The rest of the materials can be found at your local hardware store.

Strip the ends of the insulated wires.

In order for your circuit to work properly, the wires need to be totally exposed so you must strip the ends. Using wire strippers, remove about 1 inch (2.5 cm) of the insulation from the ends of each wire.

Install batteries into the battery pack

Depending on the type of batteries you are using, you may be able to skip this step. If you are using multiple batteries, you will need a power pack to hold the batteries. Push each battery in by the side taking care to put the positive and negative ends in the correct orientation.

Attach your wires to the battery pack.

The wires will be conducting your electric current from the batteries to the light bulb. The easiest way to attach the wires is to use electrical tape. Attach the end of one wire to one side of the battery, making sure that the wire maintains contact with the metal of the battery. Repeat with the other wire on the other side of the battery.

Fasten the other end of the wire to the metal screw of the bulb holder.

Take the exposed metal end of each wire and bend it into a U-shape. Loosen each screw on the light bulb holder just enough to slip the U-shape of the wire around the screw. Each wire will be attached to its own screw. Tighten the screw, ensuring that the metal of the wires remains in contact with the screw.

 

Ohms Law and Power

Ohms Law Relationship

By knowing any two values of the Voltage, Current or Resistance quantities we can use Ohms Law to find the third missing value. Ohms Law is used extensively in electronics formulas and calculations so it is “very important to understand and accurately remember these formulas”.

Ohms Law Triangle

Then by using Ohms Law we can see that a voltage of 1V applied to a resistor of 1Ω will cause a current of 1A to flow and the greater the resistance value, the less current that will flow for a given applied voltage. Any Electrical device or component that obeys “Ohms Law” that is, the current flowing through it is proportional to the voltage across it ( I α V ), such as resistors or cables, are said to be “Ohmic” in nature, and devices that do not, such as transistors or diodes, are said to be “Non-ohmic” devices.

Electrical Power in Circuits

Electrical Power, ( P ) in a circuit is the rate at which energy is absorbed or produced within a circuit. A source of energy such as a voltage will produce or deliver power while the connected load absorbs it. Light bulbs and heaters for example, absorb electrical power and convert it into either heat, or light, or both. The higher their value or rating in watts the more electrical power they are likely to consume.

The Power Triangle

So we can see that there are three possible formulas for calculating electrical power in a circuit. If the calculated power is positive, (+P) in value for any formula the component absorbs the power, that is it is consuming or using power. But if the calculated power is negative, (–P) in value the component produces or generates power, in other words it is a source of electrical power such as batteries and generators.

Electrical Power Rating

Electrical components are given a “power rating” in watts that indicates the maximum rate at which the component converts the electrical power into other forms of energy such as heat, light or motion. For example, a 1/4W resistor, a 100W light bulb etc.

 

Physics Classroom – Home

If the two requirements of an electric circuit are met, then charge will flow through the external circuit. It is said that there is a current – a flow of charge. Using the word current in this context is to simply use it to say that something is happening in the wires – charge is moving. Yet current is a physical quantity that can be measured and expressed numerically. As a physical quantity, current is the rate at which charge flows past a point on a circuit. As depicted in the diagram below, the current in a circuit can be determined if the quantity of charge Q passing through a cross section of a wire in a time t can be measured. The current is simply the ratio of the quantity of charge and time.

Current is a rate quantity. There are several rate quantities in physics. For instance, velocity is a rate quantity – the rate at which an object changes its position. Mathematically, velocity is the position change per time ratio. Acceleration is a rate quantity – the rate at which an object changes its velocity. Mathematically, acceleration is the velocity change per time ratio. And power is a rate quantity – the rate at which work is done on an object. Mathematically, power is the work per time ratio. In every case of a rate quantity, the mathematical equation involves some quantity over time. Thus, current as a rate quantity would be expressed mathematically as

As is the usual case, when a quantity is introduced in The Physics Classroom, the standard metric unit used to express that quantity is introduced as well. The standard metric unit for current is the ampere. Ampere is often shortened to Amp and is abbreviated by the unit symbol A. A current of 1 ampere means that there is 1 coulomb of charge passing through a cross section of a wire every 1 second.

Conventional Current Direction

The particles that carry charge through wires in a circuit are mobile electrons. The electric field direction within a circuit is by definition the direction that positive test charges are pushed. Thus, these negatively charged electrons move in the direction opposite the electric field. But while electrons are the charge carriers in metal wires, the charge carriers in other circuits can be positive charges, negative charges or both. In fact, the charge carriers in semiconductors, street lamps and fluorescent lamps are simultaneously both positive and negative charges traveling in opposite directions.

Current versus Drift Speed

Current has to do with the number of coulombs of charge that pass a point in the circuit per unit of time. Because of its definition, it is often confused with the quantity drift speed. Drift speed refers to the average distance traveled by a charge carrier per unit of time. Like the speed of any object, the drift speed of an electron moving through a wire is the distance to time ratio.

 

Residential Electrical Circuits Explained

What Are Electrical Circuits?

Before you put “electrical repair near me” in your favorite search engine, let’s make sure you understand what you’re looking for.

Power Circuits

If you need to transfer electricity as well as control it, you need a power circuit. When you install electrical wiring, this transfer is what you’re trying to accomplish. These are like the wiring systems in your residential home, but they can be as big as the power lines outside. If a large amount of electricity needs to be transferred and controlled, you’ll need power circuits to do it.

Electronic Circuits

Whereas power circuits are great for transferring and controlling electricity, they can’t do the same for information. That’s where electronic circuits come in. They come in many shapes and sizes. In fact, you probably have electrical circuits in your pocket right now. Cell phones are a perfect example of electronic circuits because of the amount of information flowing through that cell phone every day.

What Is a Circuit?

Now that we’ve made the distinction between a power circuit and an electronic circuit, what is a circuit anyway? In short, an electrical circuit is simply a pathway through which an electrical signal can travel. If electrons are allowed to travel from their source to their destination, your lights will light, your oven will heat, and your toaster will toast.

What Does It Mean When a Circuit Is Broken?

Just for the purpose of answering this question, picture a circuit as a circular train track. For the train to travel around that track, the track has to be continuous. Any break in the track and the train cannot continue.

Tips To Make The Best Electrical Panel Upgrades

ELECTRIC PANEL UPGRADE GUIDE

WHAT IS AN ELECTRIC PANEL?

According to the International Association of Certified Home Inspectors (InterNACHI), you should make regular checks to your electric panel, even if you haven’t needed to undertake any electrical fixes. In particular, you should check for signs of rust or scorching, both of which indicate underlying damage to the system.

WHY DO I NEED TO UPGRADE MY ELECTRIC PANEL?

As a rule of thumb, electric panels need replacing every 25-40 years, so if your home is that age, there’s a likelihood that you will need to upgrade. However, there are other key signs to look out for that will tell you when your existing system is becoming outdated.

FAULTY WIRING

When it comes to electricity and wiring within a home, safety is paramount. Faulty wiring is one of the leading causes of fires in American homes. Generally, the older wiring is, the more likely it is to be faulty, but having your electric panel inspected regularly by a professional electrician will identify any issues.

INSTALLING NEW APPLIANCES

One of the primary reasons for upgrading an electric panel is because it simply does not have the capacity to deal with modern appliances. If you are intending to install a major new appliance to your home (such as an air conditioner or hot tub), your existing electric panel may not suffice.

USE OF POWER STRIPS

As with fuse boxes, many electrical panels simply are not designed for modern electrical usage. With constant phone and laptop charging, televisions in every room, and other gadgets filling our homes, there’s simply more demand for electricity than was the case twenty years ago. A key piece of evidence for this is the limited number of wall sockets throughout homes.

 

Breaker Panel Upgrades

NB Electric is your go-to for when it’s time to upgrade your service. Whether you are adding more or newer appliances or it’s just time to replace your old electrical panel, NB Electric can evaluate your current situation, assess your needs and help determine the best option for your upgrade.

Old electrical panels can be bothersome, and in some instances, dangerous.

Some things that can happen when your panel is nearing the end of its life:

  • Lights flickering
  • Breakers that trip constantly or fuses blowing frequently
  • Not being able to use appliances at the same time
  • Melted electrical wires
  • Defective circuit breakers that fail to trip – this can result in overheating, shocks, and possibly fire

Old panels can be a hazard to your family and your home because of the potential for fires and electrical shocks.

In addition to faulty and outdated panels, there are a few other reasons to upgrade your service.

  • Renovation of your kitchen where a majority of your appliances are located
  • Adding on to your home
  • Adding a new major appliance; you have to make sure your panel can handle the load
  • Adding more outlets
  • Needing to upgrade/change your electrical service to meet homeowners insurance requirements
  • Adding a subpanel

NB Electric does all the work for you – from evaluating and planning to working with your city and utility company throughout the process. They use all of the latest and safest electrical panels and breakers.

 

Your Guide To An Electrical Panel Upgrade For Your Home

What Is an Electrical Panel Upgrade?

Understanding what the electric upgrade process entails is essential, even though a lot of people simply don’t know. If you haven’t had noticeable problems with your electrical system, you haven’t had much incentive to learn about upgrades.

Actually, though, you should know about electrical upgrades and why they are often necessary. Circuits that are faulty or overloaded could be dangerous, and possibly start a fire in your home.

Signs You Need an Electrical Panel Upgrade

Many common electrical issues are linked to a faulty electrical panel since the panel is linked to the entire electrical system. If the panel is malfunctioning, the damage is likely spread throughout the house.

As one electrical contractor put it: “Your electrical panel is like your heart—it’s vital to the overall health of your system.”

The following sections explain some reasons why you might want to consider an electrical panel upgrade for your home in the near future:

Your Home Still Has a Fuse Box or Your Electrical Panel is Unsafe for Other Reasons

Fuse boxes were the norm for homes through the 1960s, and quite a few homes still have them today. If yours is one of them, the fuse box should be replaced.

It’s not that the fuse box is dangerous in and of itself, though it can be pretty inconvenient to have to keep replacing fuses. Rather, it’s the various stopgap measures people may have taken over the years to keep the boxes functional.

 

How to Locate and Label Your Electrical Panel

Electrical Panel Safety

If you notice anything suspect about your electrical panel, such as rust, corrosion, melting plastic, or any other damage, call your electrician right away.

Make sure your home is outfitted with ground fault circuit interrupters (GFCIs) and arc fault circuit interrupters (AFCIs). These “circuit interrupters” will cut off power in dangerous situations to protect you from electrocutions and building fires. Keep in mind that if you have AFCIs and GFCIs installed at the breaker box, you may need to reset your breakers more frequently. Learn more about protecting your home from electrical hazards with our safety checklist.

Things to Consider

Once you choose to index your switches, you will need to decide how you want to label them. Do you want to take a casual tone and label the switch “Molly’s Room” or “TV Room” or will you use a less-personal tone and instead of “Molly’s Room” say “north wall of west bedroom”? There are pros and cons for both labeling styles.

How to Label Your Electrical Panel

Luckily, you found your electrical panel, opened it up, and found all the circuits clearly labeled. Still, it’s a good idea to double-check its accuracy.

Each switch controls something different. You can recruit someone to help you and together you can figure out which switch goes to what by simply flipping them and finding out.

When Do I Need to Access My Panel?

The main reason you need to locate your panel is to turn power back on to a circuit. If a fuse has blown due to an overloaded outlet in your home, you’ll need to locate the panel in order to replace the fuse and restore power. If the breaker trips, you need to find the tripped breaker and turn it all the way off before you flip it back on again.

 

Electrical Panel Upgrades

Your electrical panel regulates the electricity coursing through your home. If too much electricity is demanded on a circuit, a circuit breaker is tripped in the electrical panel to stop the electricity from overloading the wiring. An overload can cause a fire, so it’s the job of the electrical panel to break the circuit and regulate the electricity in the system to keep your home and family safe.

Unfortunately, as your home gets older, the electrical panel could have a hard time keeping up with the increased electrical demands on the system. Your appliances, televisions, computers, HVAC systems, lights and other electrical gadgets are increasingly energy efficient, but the average modern household uses more gadgets than ever before. If your home is more than 10 years old, your electrical system may not be able to keep up with your electrical demand. How do you know for sure?

How an Electrical Panel Works

The main power line from your electric company connects directly to a power meter on the outside of your home. Then the line goes directly to the electrical panel. You can usually find your home’s electrical panel in a garage, utility room, closet or basement. It’s usually painted gray.

When you look inside the electrical panel, you will see rows of switches. These are the circuit breakers that distribute the main power line into smaller branch lines. Some of the switches are doubled or tripled together because they power appliances that require large electricity loads, such as air conditioners and electric dryers. Inside the electrical panel door there should be a label that maps out the locations of the outlets and appliances according to the numbers on the switches. The switches also have numbers on them that tell you how many amps the branch line can carry before the breaker switch is tripped. The electrical panel also has a main power breaker that can turn off power to the whole system.