A beginner's guide to wiring your home

Welcome, homeowners, to the electrifying world of electrical cables! Whether you’re a seasoned DIY enthusiast or just beginning to explore the wonders behind your walls, understanding the language of cables is a crucial step towards a safer and more informed home.

In the vast landscape of electrical systems, cables play a crucial role in ensuring the seamless flow of power throughout your home. But fear not, fellow homeowners, as we embark on a journey to decode the mysteries of electrical cables, demystifying the terminology and shedding light on the wires that power our lives.

Types of Cables

Let’s start with the basics. A cable is a composite of conductors and their insulated surroundings. It’s the lifeline of your electrical system, transmitting power with precision. Now, let’s delve into the specific types you might encounter.

Twin and Earth Cable

Meet the domestic superhero of cables – the Twin and Earth. This flat grey therm-plastic sheathed cable boasts two single conductors, which are colour-coded for your convenience. Brown, the line conductor, and blue, the neutral conductor, dance together inside. Sandwiched between them is the unsung hero, the Circuit Protective Conductor or ‘earth,’ ready to shield your home.

Flex Cable

Flex cables are the gymnasts of the electrical world. With a soft rubber or thermoplastic outer sheath and individually insulated conductors, they flex and bend with grace. Their fine copper strands make them the go-to choice for areas requiring repeated flexibility.

SWA Cable

When protection is paramount, enter Steel Wire Armour (SWA). Encased in a layer of steel wire, SWA cables are the knights in shining armour, guarding against potential hazards. Ideal for areas demanding a high degree of protection, these cables are the guardians of your electrical kingdom.

LSHF Cable

Imagine a cable that stays cool under pressure – that’s the Low Smoke Halogen-Free (LSHF) cable. Engineered with insulation designed to emit minimal smoke and zero halogens during a fiery encounter, these cables prioritise safety without compromising performance.

‘Singles’ Cables

In the realm of singular elegance, ‘Singles’ cables stand alone. A colloquial term for self-contained single conductors, they often feature PVC insulation. Simple yet effective, these cables are the soloists of your electrical orchestra.

Units of Measurement

Now that we’ve unravelled the cable tapestry let’s acquaint ourselves with the units that measure the dance of electrons.

  • Ohms – Ohms, the resistance warriors. Symbolised by Ω, they dictate how readily electrons navigate through a conductor.
  • Watt-Watts, the power brokers. Denoted by ‘W,’ they quantify the energy flow within the electrical circuit.
  • Voltage – Voltage is the electric pressure. Represented by ‘V’ or ‘U,’ it measures the potential difference between the two points in your electrical domain.
  • Amperes – Amperes, the current conductors. Marked by ‘A,’ they define the flow of electrical current, a vital heartbeat in your system.
  • AC vs. DC – Alternating Current (AC) and Direct Current (DC) are the dynamic duo of electricity. AC reverses direction periodically, mirroring the UK’s power distribution. DC, a one-way street, powers your batteries.

Protective Devices

Now that our cables take the spotlight, it’s essential to explore what shields them against the perils of electrical warfare—enter protective devices.

These devices play a central role in the electrical system, acting as guardians for cables, electrical components, and systems, shielding them from the dangers of electrical over-voltage, over-current, short-circuits, and other harmful effects.

They provide a defence against power surges, spikes, and voltage transients. The most common protective devices – circuit breakers, fuses, and surge protectors.

Recognising their significance, it’s advisable to consult with a skilled electrician to ensure they equip your electrical system with these essential safeguards, preventing major damages and ensuring its resilience.

Circuit Breaker

A protector in shining armour, the circuit breaker shields against overload and fault currents. It stands vigilant, ready to sever the connection in times of crisis.


The silent hero, the fuse. When excess current dares to trespass, it sacrifices itself, breaking the circuit and preventing electrical mayhem.


Residual Current Devices, the vigilant guardians. Whether an RCCB is safeguarding a circuit bank or an RCBO defending a single circuit, they monitor currents, tripping when danger lurks.


Surge Protection Devices, the lightning catchers. Designed to limit sudden energy surges, they shield your home from transient over-voltages.

Main Switch

Though not a protector, the main switch reigns supreme. Nestled in your consumer unit, it holds the power to disconnect the electrical supply to your entire domain.

Earthing and Bonding

Descending into the grounding realm, let’s unveil the secrets of a secure electrical haven. Understanding the distinctions between earthing and bonding is crucial for the safety of you and your family. Earthing involves connecting an electrical system to the ground, ensuring it stays at the same potential as the Earth’s surface.

This safeguards against electric shock by maintaining electricity at a safe level. Conversely, bonding is the process of linking two or more metal components to ensure they share the same potential. For comprehensive guidance on earthing and bonding, consider consulting with a skilled electrician to fortify the safety of your electrical system.

Earth and Earth Electrode

Earth is the bedrock of safety. Defined as the general mass of the earth, it receives reverence in the form of copper rods, ensuring a grounded haven in TT earthing systems.

Bonding Conductor

The conductor of connection. Bonding conductors create an equipotential bond, uniting extraneous conductive parts and mitigating electric shock risks.

Earthing Systems (TN-S, TN-C-S, TT)

Welcome to the varied landscapes of earthing. From TN-S, where line, neutral, and earth enter as one, to TN-C-S, merging neutral and earth, and TT, relying on locally fitted earth electrodes.

Test and Inspection

Now equipped with the basics, let’s embark on the journey of ensuring electrical health and safety. For a thorough assessment and professional guidance, consider consulting with a skilled electrician to ensure the well-being of your home’s electrical systems.

Approved Voltage Indicator

A trustworthy sidekick, the voltage detector meets British Standards. It is essential to validate the safety of any circuit or equipment before your DIY endeavours.

Safe Isolation

The detective works before the electrical operation. Ensuring the absolute absence of electricity in the circuit under scrutiny, protecting you from potential shock.

Multi-function Tester

A superhero amalgamation of testing facilities. The KEWTECH KT64 and its peers ensure a comprehensive check-up, leaving no room for electrical ailments.

Proving Unit

The litmus test for your voltage detective. A device providing a known voltage source to verify the efficacy of your approved voltage indicator.

Departure and Design Current

The rebels in the regulated world. Departures are deliberate deviations, but they demand declaration, assuring safety parallel to the wiring regulations.


Electricians and homeowners, rejoice in your newfound mastery of electrical cable secrets! With this knowledge, homeowners like you become the commanders of your electrical domain. Beyond mere wires, understanding the language of cables empowers you to create a safer and more electrifying home. Stay wired for more enlightening articles on home improvement, and for professional electrical assistance, consider consulting with a skilled electrician at the beginning of your electrifying journey.