Homeowner’s safety and efficiency guide to electricity and wiring
As a homeowner, you come in contact with electrical circuits on a daily basis. Turn the lights on. Grab milk from the fridge. Tune in to your favourite station to catch the news over breakfast. Without thinking of it, you’ve probably controlled a few dozen circuits before you pull out of the driveway
do you have any idea how the electrical circuits in your home actually work? Why you have to flip those pesky circuit breakers, or why the stereo salesman keeps trying to stick an expensive surge protector in the basket every time you buy an appliance? Most people don’t, besides what they forgot to remember from that summer camp merit badge. Thought you were the only one who slept through those lectures, eh?
The electricity basics
An electrician in Voorhees said that when thinking about electricity, there are three important values to know: Watts, Ohms, and Volts. You will find the maximum safe value for each listed on things like extension cords and light fixtures. I’ll explain electricity using the analogy of a water pipe. This analogy is likely to make any electrical engineers reading begin to babble about electrons till the short circuit, but it’s a great functional explanation that requires no knowledge of physics.
Volts
Volts are a measure of electrical potential. Energy is pushed from the source at a rate expressed in volts. Volts are like water pressure. Power lines in the street are high-voltage, like water from a fire hydrant. Home electricity comes in 120v for general use, which is the equivalent of a garden hose–good for most general tasks. Some special equipment, like pool pumps or laundry machines, require more power and get 240v–the electrical version of a pressure washer.
Within your home, many devices will reduce the voltage even more. A computer may only need 24v, while a cellphone charger may only use 5 volts. Their charges will step-down the power from your wall to a lower pressure that so it doesn’t fry the delicate internal electronics.
For efficient delivery, power from the main generator station to local substations flows at extreme voltages, usually around 150,000 volts. Voltage is reduced at several sub-stations until it reaches around 3,000 volts, and pole-mounted transformers finally reduce that to 120v or 240v before final delivery to your home’s junction box.
The Homeowner’s DIY Guide to Electrical Wiring
Handle residential wiring projects correctly, safely, and according to the National Electrical Code (NEC). Filled with clear photos and helpful diagrams, The Homeowner’s DIY Guide to Electrical Wiring shows you how to quickly and easily navigate the portions of the NEC that pertain to residential installations.
This hands-on resource covers basic electronics and explains how electrical service progresses through your home. It describes how to install and test electrical systems and lighting, repair appliances and TVs, and upgrade to the latest innovations such as home networking, home automation, and alternate power systems. You’ll learn the procedures used by professional electricians to create the kind of quality work that will pass inspection and add value to your home
The Homeowner’s DIY Guide to Electrical Wiring shows how to:
Protect against fire and shock hazards
Track electrical service from the point of connection to the entrance panel
Follow NEC requirements for residential projects
Work with test equipment and installation tools
Use the best techniques for quality electrical work
Design and install indoor and outdoor lighting
Maintain and repair electrically powered appliances
Fix CRT, plasma, and LCD TVs
Design a data and communications network and install coax, USB, and Ethernet cabling
Install a home automation system
Install backup and alternate power systems
Work with smart meters
Home Wiring Guide
This is an overview of a typical UK home wiring. All circuits begin from the consumer unit.
There are 3 main kinds of circuits:
Ring main
Radial circuit
Hard wired appliance circuit
Safety
Product must be installed by a competent person (e.g. a qualified electrician) in accordance with the relevant clauses of the current edition of the IEE Wiring Regulations (BS 7671: Requirements for Electrical Installations) and appropriate statutory regulations.
Switch off main power at the consumer unit.
Remove the circuit fuse to isolate the circuit you are working on and keep the fuse in a secure location to avoid accidental replacement.
Turn off the circuit breaker of the circuit you are working on and lock it if possible.
Place a note in a visible location to advise that you are working on the circuit.
Make sure the circuit is not live by checking it with a socket tester or voltage tester.
The consumer unit or commonly known as fuse box is the heart of a home wiring installation. It is usually mounted near the energy meter. A modern consumer unit as pictured above houses modular electrical devices called circuit breakers. There are 4 main kinds of circuit breakers in a common household: Main switch, MCB and RCD.
The main switch functions like a master switch that is able to isolate the incoming electrical power supply to the house. After the main switch the incoming power supply is split to several circuits such as power, light and appliance.
Each circuit is protected & controlled by a miniature circuit breaker MCB. When the circuit draws current above the MCB rated current, the MCB trips and turns off the power to protect the devices on that circuit.
WIRE COLOR CODING
There are many wire identification standards, and many of them rely on color codes. Not all electrical wiring color codes are the same, though, and some even contradict each other. Which standard should be used in your facility? It depends on your location, installation type, voltage, and other factors.
Note that older installations may use different color codes. In workplaces, it’s a good idea to document the color code that is being followed. This way, work will be safer, and future maintenance will be easier.
Electrical Wiring Color Codes
In the United States, the following color codes are typically used for power wires in “branch circuits,” the wiring between the last protective device (such as a circuit breaker) and the load (such as a tool or appliance).
120/208/240 Volt AC Wire Colors
These systems are common in home and office environments.
Phase 1 – Black
Phase 2 – Red
Phase 3 – Blue
Neutral – White
Ground – Green, Green with Yellow Stripe, or Bare Wire
If the wiring system has one phase at a higher voltage than the others, using a “high-leg” connection, that phase’s wires should be marked with orange. (This is required in NEC article 110.15.) However, these high-leg delta systems are uncommon with newer installations.
277/480 Volt AC Wire Colors
These higher-voltage systems are common for industrial motors and equipment.
Phase 1 – Brown
Phase 2 – Orange
Phase 3 – Yellow
Neutral – Gray
Ground – Green, Green with Yellow Stripe, or Bare Wire
A practical, money-saving guide to home electrical wiring
Handle residential wiring projects correctly, safely, and according to the National Electrical Code (NEC). Filled with clear photos and helpful diagrams, The Homeowner’s DIY Guide to Electrical Wiring shows you how to quickly and easily navigate the portions of the NEC that pertain to residential installations.
This hands-on resource covers basic electronics and explains how electrical service progresses through your home. It describes how to install and test electrical systems and lighting, repair appliances and TVs, and upgrade to the latest innovations such as home networking, home automation, and alternate power systems. You’ll learn the procedures used by professional electricians to create the kind of quality work that will pass inspection and add value to your home.
The Homeowner’s DIY Guide to Electrical Wiring shows how to:
> Protect against fire and shock hazards
> Track electrical service from the point of connection to the entrance panel
> Follow NEC requirements for residential projects
> Work with test equipment and installation tools
> Use the best techniques for quality electrical work
> Design and install indoor and outdoor lighting
> Maintain and repair electrically powered appliances
> Fix CRT, plasma, and LCD TVs
> Design a data and communications network and install coax, USB, and Ethernet cabling
> Install a home automation system
> Install backup and alternate power systems
> Work with smart meters