Topic: 📖 Understand & explain
Understand & explain - how-to guides
How your home electrics actually work - cable colours, ring vs radial, MCB vs RCD, live vs neutral, current vs voltage.
25 guides in this topic
Written specifically for UK domestic wiring - BS 7671, TN-C-S / TT earthing, and the fittings you actually find in a British consumer unit.
Ring and radial socket circuits explained
What makes a ring final circuit different from a radial, how to tell which type your home has, why UK housing settled on ring mains, and what changes when you add new sockets.
Read the guideWhat is a smart home energy panel?
Smart home energy panels add real-time circuit monitoring, app control and time-of-use automation to your consumer unit. A UK guide to what they do, which systems suit which homes and what installation involves.
Read the guideUnderstanding arc fault detection devices (AFDDs)
What AFDDs are, how they differ from RCDs, what BS 7671 Amendment 2 says about socket circuits, and what to expect when an electrician fits one in your consumer unit.
Read the guideUnderstanding bathroom electrical zones (BS 7671)
A plain guide to BS 7671 bathroom zones 0, 1 and 2 - what equipment is allowed where, IP ratings explained, heated towel rails, shaver sockets and Part P implications.
Read the guideCable safe zones (prescribed zones) explained
Where you can and cannot run hidden electrical cables in UK walls and ceilings under BS 7671 -- what the prescribed zones are, why they exist, and what to check before drilling into any wall.
Read the guideUnderstand diversity and maximum demand in domestic installations
Why every appliance in your home does not run at full load simultaneously, how BS 7671 Chapter 31 and the On-Site Guide Appendix A define maximum demand, and how an electrician sizes your consumer unit and meter tails co
Read the guideUnderstand your Economy 7 storage heaters
How Economy 7 night storage heaters work, how the dedicated circuit is wired, how to set the controls correctly for cheaper overnight charging, and when to call an electrician.
Read the guideUnderstanding EICR condition codes: what C1, C2, C3 and FI mean for your home
Plain-English guide to EICR condition codes for UK homeowners and landlords. What C1, C2, C3 and FI actually mean, which codes make a report unsatisfactory, and what to do next.
Read the guideWhat is an Electrical Installation Certificate?
A plain guide to the UK Electrical Installation Certificate (EIC) -- when you need one instead of a Minor Works Certificate, what the Schedule of Inspections and Test Results contain, and what to do if you have lost your
Read the guideUK electricity supply: cutout, meter and consumer unit explained
Who owns the service cutout, the meter, the tails and the consumer unit in a UK domestic property? A plain explanation of the supply chain, who is responsible for each part, and what that means for fault reporting.
Read the guideUnderstand IP ratings for UK electrical equipment
The IEC 60529 / BS EN 60529 IP code explained - what the two digits mean, the ratings required by BS 7671 in bathroom zones and outdoors, and how to choose the right fitting.
Read the guideMCB selectivity and discrimination: why your whole board trips when it should not
Why some consumer units trip the whole board when one circuit faults, and how selectivity and discrimination between MCBs and RCDs prevents unnecessary blackouts. UK domestic guide.
Read the guideWhat is a Minor Electrical Works Certificate?
A plain guide to the Minor Electrical Installation Works Certificate -- what it covers, when you need one, how to read the condition checks, and what to do if you have lost yours.
Read the guideWhat goes inside a modern UK consumer unit in 2025
What a correctly specified UK consumer unit contains in 2025: steel enclosure, main switch, surge protection device, RCBOs and possibly AFDDs. Understand the components before getting a quote.
Read the guideUnderstand old UK wiring colours (pre-2004)
What the old UK cable colours mean, how red and black map to current brown and blue, what to watch for on switch returns, and why you must test before touching.
Read the guideUnderstand open PEN conductor fault protection
What a broken PEN conductor means on a UK TN-C-S (PME) supply, the danger it creates to earthed metalwork, and how BS 7671 Section 722 requires open PEN protection for EV charger installations.
Read the guideUnderstand Part P: what electrical work you can do yourself
Part P Building Regulations explained for homeowners: which electrical jobs are notifiable, which are not, how self-certification works, and what paperwork you should receive.
Read the guideType AC, A and B RCDs for home EV chargers: what you need to know
Why a standard Type AC RCD is not enough for a home EV charger in the UK. What Type A and Type B RCDs detect, when each is required under BS 7671, and what your installer should specify.
Read the guideOld UK rewireable fuse boxes explained
What the old Wylex and MEM rewireable fuse boards found in UK homes actually are, why they offer less protection than a modern consumer unit, and when to get a quote for an upgrade.
Read the guideUnderstanding surge protection devices (SPDs)
What surge protection devices do, why the 18th edition Amendment 2 made them the default for new UK domestic work, the three types of SPD, and what to ask when getting quotes.
Read the guideUnderstand TT earthing in UK homes
What a TT earthing system is, how it differs from TN-C-S (PME) and TN-S, how to identify which type your home has, and why TT properties need an earth rod and full RCD protection throughout.
Read the guideUnderstand the three UK earthing systems (TT, TN-S and TN-C-S)
A plain-English guide to the three UK domestic earthing systems. What TT, TN-S and TN-C-S mean in practice, how to identify which type your home has, and why it matters before any consumer unit work.
Read the guideUnderstand voltage drop in UK domestic wiring
A practical UK guide to calculating voltage drop in domestic circuits under BS 7671 Regulation 525 - design current, mV/A/m values, worked examples for lighting and power, and when to upsize the cable.
Read the guideUnderstanding your consumer unit (fuse box)
A plain-English guide to what is inside your consumer unit - MCBs, RCDs, RCBOs and old rewireable fuses explained. Includes the signs that an old fuse board needs replacing.
Read the guideHow UK home lighting circuits work
An honest guide to how UK domestic lighting circuits are wired - loop-in at the ceiling rose, junction box method, switched live, and what it means for safe DIY work.
Read the guideOther topics
🔧 Installation & wiring
Wire, fit and install - cable runs, sockets, switches, consumer units, cookers, showers, outdoor circuits.
🛡️ Safety & testing
Safe isolation, initial verification, insulation resistance, earth-fault loop, continuity, bonding.
🔍 Fault finding
Diagnosing tripping MCBs, flickering lights, dead sockets, buzzing switches and other common faults.
🔁 Replace & upgrade
Swapping old kit for new - light switches, sockets, fusewire, fuse boxes, consumer units, luminaires.
📋 Planning & regulations
What is notifiable, when to call an electrician, choosing consumer units and EV chargers, BS 7671 basics.
⚡ General guides
Working with cable, wiring accessories and everyday tools around the home.