Surge Protection Devices (SPDs) Explained: What They Are and What BS 7671 Amendment 2 Requires
Voltage surges from lightning and switching events can destroy electronics silently and instantly. This guide explains how Surge Protection Devices work, the main SPD types, where BS 7671 Amendment 2 requires them, and how to choose the right SPD for a domestic or commercial installation.
AFDDs Explained: Arc Fault Detection Devices and BS 7671 Requirements
Arc Fault Detection Devices (AFDDs) are required by BS 7671 in specific higher-risk residential locations and recommended more widely. This guide explains what AFDDs are, how they detect dangerous arcing faults that MCBs and RCDs miss, where they are required, and whether you need one.
Why Does My MCB Keep Tripping? Overload, Short Circuit and Fault-Finding Guide
An MCB that keeps tripping is usually caused by overload, short circuit, appliance failure, damaged wiring, or an incorrectly rated breaker. This guide explains how to identify the cause safely and when to call an electrician.
How to Wire a Ring Main Circuit: The UK Ring Final Circuit Explained
The ring main is uniquely British and widely misunderstood. This guide explains exactly how a ring final circuit works, why it uses 32 A protection with 2.5mm² cable, how spurs work, and what BS 7671 requires.
What Is an RCBO? The Difference Between RCD, MCB and RCBO Explained
An RCBO combines overcurrent protection with earth leakage detection in one device. This guide explains how it works, how it compares to MCBs and RCDs, and when you should use one.
Ring Circuit vs Radial Circuit: What's the Difference?
Ring circuits and radial circuits are the two ways to wire socket outlets in UK homes. This guide explains how each works, when to use each, cable sizes, spur rules, and how to simulate both topologies in a free browser-based circuit simulator.
Distribution Board Explained: How a Consumer Unit is Wired
The distribution board is the heart of every electrical installation. This guide explains what's inside a consumer unit, how it distributes power to every circuit in a building, and how to simulate a multi-circuit distribution board using a free electrical circuit simulator.
What is an RCD and Why Do You Need One?
An RCD can disconnect a dangerous earth fault fast enough to save your life. This guide explains exactly how Residual Current Devices work, why they're mandatory in modern wiring, and how to test RCD protection safely using a free electrical circuit simulator.