Understanding The Basics of Electrical Wiring

Suppose you run into an electrical wiring issue and need a quick solution. Learning the basics of electrical wiring can help you perform many simple repair and maintenance tasks. 

Sometimes you can’t call an electrician fast enough, and in these situations, you need to know what you are dealing with.  

Most electrical repairs revolve around identifying the right type of wiring and knowing where it should go. With so many wires to look through, keeping track of their identification can get a little confusing. 

Learning the basics will also help you avoid any hazardous situations in the future. 

Understanding Electrical Wiring

You need to identify the correct electrical wiring to do a successful electrical repair or remodel. You must know which one to buy and how to properly install it in the complete system. 

If you want to take up an electrical project, learning the basics is a crucial place to start. You must also look at the terminology, the materials and equipment needed, plus any other special device. 

Another element to keep in mind is the electrical codes. Almost every home today is built according to electrical guidelines that ensure the safety of the building. 

These codes also often tell you the identification of specific wiring to make the process easier. By keeping these in mind, you can get more comfortable with repairing electrical wiring. 

What Is Electrical Wire Colour Coding?

This is an important element that you must remember when doing any repairs. Colour coding is used on both the outer sheathing of the electrical wires and on the separate conduction material within the cable. 

You can also find colour coding on the conduit of the wire. Learning about the colour coding can help you determine which wiring is used where. These colours are also important for keeping your electrical system organised and maintained. 

Sometimes cable colours also refer to the size of the wiring inside the cable sheath and its amperage rating. This is another great way to distinguish between various wiring and avoid any hazardous situations. 

The colour on individual conducting wires don’t always indicate the rating or size but instead where and how it should be used. 

The colour for wiring often depends from country to country. In the UK and Ireland, you can often find information about wire colouring from electrical guidelines. 

Here’s a look at the most important wire colours in the UK.    

Green And Yellow Earth Wire

The earth wire is one of the most important safety wires in an electrical system. It stops you from getting into any hazardous situations, such as an electric shock. 

The earth wire creates a path for the current to flow easily. At the same time, the earth wire also prevents the current from travelling into a faulty circuit. This prevents the fuse from short-circuiting.    

Brown Live Wire 

The live wire is responsible for carrying the electric current from your appliance to the power supply. 

Blue Neutral Wire

The neutral wire takes the current away from your appliance and back into the main power supply. 

What Are The Old Wire Colours In The UK?

The colour coding you see today reflects a recent change made to UK’s wiring. Older wiring had different colour combinations to fit previous electrical guidelines. 

You might still find these colour combinations in some older homes and buildings. The colour coding of older wiring systems in the UK includes:

• Earth Wire - green and yellow but with no sleeve.
• Live Wire - Red
• Neutral Wire - Black 

What Did The Wiring Colours Change?

The new wiring colour became mandatory in the UK in 2006, but many electrical systems started using them in 2004. 

While it may seem a little complicated to have two different systems, the new systems were created to match with other European countries. The goal was to create a harmonised electrical wiring system in the region. 

Nowadays, you are more likely to come across the new wiring system instead of the old one. In April 2006, the government made a legislative decision to outlaw the use of the old colour coding. 

This law was highlighted in BS 7671, an important guideline for all electrical wiring. But, as we said earlier, some buildings still use the old wiring system, especially if they haven’t been updated. 

The guidelines don’t state those old buildings need to be upgraded, but instead, any wiring system created after 2006 should always use the new coloured wiring. 

What Are The Important Elements In An Electrical Circuit?

Once you have figured out the wire colour coding, it’s time to take a look at the electrical circuit. In the UK, there are three common types of electrical circuits. These include:

• Ring main
• Radial circuit
• Hard wired appliance circuit

All these systems begin at the consumer unit and make their way through an intricate system. Let’s break down all the different electric current pathways in these systems. 

Consumer Unit

The consumer unit, or the fuse box, is the heart of a home wiring installation. You can find this unit near the energy meter.

A modern fuse box contains modular electrical devices called circuit breakers. In a common household consumer unit, circuit breakers have three main types. These are the main switch, multiple circuit breakers (MCB) and residual current devices (RCD). 

The main switch is the central component that isolates the incoming electrical current. This is then supplied to your home. 

Once the current reaches the main switch, it splits into several circuits, including general power, light fixtures and appliances. Each circuit component is controlled and protected by a miniature circuit breaker MCB.

When the system draws the electrical current above the MCB’s capacity, the MCB trips and shuts off the power to protect any devices using the circuit. In many modern homes, fuse boxes are also equipped with a residual current device. 

RCD is a highly sensitive safety component that shuts off electricity when it identifies a fault in the system. 

This component is designed to prevent electrical fires and shocks caused by faulty earth wires. If you have any outdoor devices powered by the main circuit, always get the RCD protection. 

If you’re doing electrical work, you will see that each circuit breaker is carefully labelled for identification. This makes it easy to conduct work without running into any problems. 

The Cables

Think of the cables are the travel source for the electrical current. These components are such an integral part of an electrical circuit as they can or break them. 

As we’ve mentioned before, cables are colour coded for better identification and safety. The most common wires in a home electrical system include copper, live, neutral and earth wire. 

Electrical energy flows to the devices along the live wire and travels back along the neutral wire. The earth wire, which is located between the neutral and live wire, provides a safe travelling route for any leaking current from the circuit. 

This leakage is often the result of a poor connection or electrical fault. In short, the earth wire prevents any major electrical disaster from occurring. With the evolution of wiring standards in the UK, several changes have been made to the current electrical system. 

One of the changes we mentioned before was the wire colouring. Additionally, the newer cables are much safer to handle as they adhere to strict electrical guidelines. 

If you are moving to the UK from any other part of Europe, you will find many similarities in the electrical system. This harmonisation makes it much easier for everyone to get familiar with their electrical wiring.

If you are wiring a new property, it is crucial that you follow BS7671 wiring regulations. Also, make sure the wires are in good condition before you start using them. 

The average lifespan for a wire is around 30 to 40 years as its condition deteriorates over time. If your property uses old wiring, you should conduct a safety test or upgrade it to avoid any future problems. 

Radial Circuit

The radial circuit refers to a single wire running from the fuse box circuit breaker to several electrical devices. 

The wire finishes when it reaches the last device along the system. The current rating of a radial circuit restricts the area where the circuit can reach. 

For example, a 20A radial circuit should only supply up to 50 square meters. For a 32A radial circuit, the supply should only reach around 100 square meters. 

Ring Main System

A ring main system begins at the fuse box and connects to various electrical devices. These devices are usually sockets. The connection then returns back to the consumer unit.

Once this connection is complete, the current can flow from any end of the ring. Unlike the radial system, this setting increases the load-carrying capacity without the need for bigger wiring. 

The ring main system typically has a capacity of 32A, meaning it can power a location of 100 square meters. 

Spurs

Spurs refer to the short branch of the cable located in the ring main circuit. This branch can come from an existing electrical device or a junction box somewhere in the system. 

Any unfused spur can only supply energy to one socket or connection. Remember that the total number of spurs should not exceed the number of devices connected to a ring main system. 

Appliance Circuit

High voltage or hardwired appliances such as hot water systems, cookers and electric showers need dedicated circuits from the fuse box. These circuits often have higher gauge wiring and are protected from higher capacity circuit breakers. 

These hardwired appliances are controlled by specific connection units. The switches for these units are typically two-pole, meaning it is both live and neutral at the same time. 

Bonding And Earthing

Bonding and earthing should be implemented in every electrical system to comply with BS7671. This ensures the safety of your electrical wiring system. 

Both bonding and eating use the yellow and green cable colour coding. Earthing is a crucial requirement in every home's electrical wiring as it provides protection against electrical shocks. 

Generally, electrical energy always takes the shortest pathway to flow from the fault to the ground. If a circuit system doesn’t have earthing and a fault occurs, the metal body of the appliance can become live. 

For example, if you turn on a faulty switch, it could become live and electrocute you. 

If a fault occurs in a properly earthed system, the electric current will travel through the earth wire to the ground. This will trigger the circuit breaker in the fuse box to shut off the power supply immediately. 

Bonding refers to a connection between all metal components and the earth circuit. Let’s say you touch a faulty hardwired appliance and then touch a metal tap on your sink; you would become the earth pathway and receive a life-threatening electric shock. 

The lack of bonding will create a chain effect that causes your home's all metal components, including metal water pipes, to carry live electrical energy. With this in mind, you must carry out a proper bonding in your circuit system. 

What Are Electrical Wiring Connections?

Once you’ve understood the basics of an electrical system, it’s time to look at the different types of connections. Electrical wiring connections are important because they keep your house powered up. 

Without a proper connection, you will face annoying interruptions or potential hazards. Here’s a look at two of the most important types of electrical connections. 

Single-Phase Wiring

Single-phase wiring is the most common way to make an electrical connection. You can usually find this type of wiring in a residential property. 

In this system, you will find the typical earth, live and neutral wiring. In a single-phase system, you will only find one supply of alternating current with a voltage that varies from positive to negative. 

A single AC current works well in residential properties because lighting and low-voltage appliances are compatible with any power variations. 

Three-Phase Wiring

Three-phase wiring is commonly used in industrial settings where heaving appliances take a lot of currents. This type of connection is less likely to experience faults when paired with higher voltage appliances, such as heavy machinery etc. 

In a three-phase system, you will find three separate live wires. The current in each live wire is not in phase with the others, so it’s called a three-phase system. 

You won’t always find a neutral wire here which means there are two combinations to look at for:

• Five wire configurations - three lives, one earth and a neutral
• Four wire configurations - three lives and one earth

Just imagine a three-phase system with three AC currents working together to ensure power is always supplied. Without this running supply of energy, heavy machinery would not function properly. 

One thing to note is that in the UK, a three-phase system supplies a higher voltage of 415V compared to one-phase system’s 240V. 

What Is Wire Sizing?

The correct wire size is essential to any electrical wire installation. The wire size describes the diameter of the wire’s metal conductor. This also takes into account the wire’s gauge capacity. 

The gauge refers to the unit’s current-carrying capacity or how much voltage the wire can safely handle.

 When selecting the right wire, consider its gauge, the capacity and what the wire will be used for. The wrong wire size could increase the risk of short circuits and electric fire. 

What Are The Different Types of Cables?

Cables usually contain multiple wires to perform one or more functions. Here’s a look at all the different types of cable and how you can use them.

Communication Cables

A communication cable is a cable that transmits information through a current of numerous frequencies. 

Communication cables differ from power cables because power cables are manufactured for high currents and voltages. Power cables are used only for supplying energy; however, communication cables differ. 

Communication cables are designed for low currents and low voltage. Communication cables are commonly used for electronic circuits, data transmission, ethernet connections, and networking. 

In the simplest terms, a communication cable is electrical cable equipment that transmits information signals between geographically separated areas. 

These areas can be close to each other or far apart. A well-connected communication cable will send information signals quickly and efficiently regardless of the distance.   

Direct Burial Cable

Standard electrical cabling is designed for indoor installation, where it remains dry and is protected by ceiling, wall and floor structures. 

You should use a direct burial cable for outdoor installations or when you want to run wires underground. As the name suggests, these cables can be installed underground. 

You can also run there without a conduit depending on local building codes. These wires have a solid vinyl sheath that provides complete protection from moisture. 

Fire-resistant Cables

There is a high risk of fire-related accidents in any location with many wiring mechanisms. To avoid major power failures, power plants use a fireproof cable. 

If a building experiences a fire-related accident, fire-resistant cables make it possible for emergency systems to function, ensuring everyone’s safety. 

Fire-resistant cables are used to power emergency systems such as fire alarms, emergency lighting, fire detection, and voice alarm systems. 

Most manufacturers create fire-resistant cables with non-flammable isolated mica tape wrapped around copper wires to protect from a fire. 

Typically, regular cables emit smoke which greatly hinders emergency efforts. However, with fire-resistant cables, you don’t have to worry about this issue. 

Fireproof cables are halogen-free, unline regular cables, which means they don’t emit smoke that ruins emergency procedures. 

Do You Need trunking For Electrical Wiring?

Metal trunking houses electrical cables and protects them from hazardous elements. They are often hidden behind plasters within a wall. Some metal trunking is also installed underneath the flooring.

Metal trunking is important because they keep everything in position and prevents your wiring from mixing up. You can also use them as a form of cable management. Steel trunking keeps your electrical wiring safe and in operation. 

Steel trunking’s safety features house all the electrical currents and stop the spread of fire in case of a short circuit. With these reasons in mind, investing in trunking for your electrical wiring is worthwhile. 

Manage Your Wiring With Meteor

Planning to upgrade your wiring or need cables for a new build? Visit Meteor Electrical and browse through our high-quality cabling. 

At Meteor, we only carry products that use cutting-edge technology and keep customer service in mind. For all your wiring needs, visit Meteor.