Knowledge base
Short, plain-language guides to the parts inside your panel and the rules behind our checks.
Start here
How to plan and build a consumer unit, step by step
The whole path in one place: what to note down before you start, how circuits and protection get chosen, what to buy, the order to assemble in, and where a licensed electrician has to take over.
Read the guideBasics
What is an RCD, and how does it detect leakage?
An RCD compares the current going to appliances with the current coming back. If some returns another way, it can disconnect the supply. See how with a washing machine.
Read articleRCCB or RCBO: what is protected and what switches off?
An RCCB detects leakage; an MCB protects against overload and short circuit. An RCBO combines both functions. The practical difference becomes clear when one faulty circuit also cuts power to its neighbours.
Read articleB16 or C16: understanding your circuit breaker
A circuit breaker disconnects a circuit during an overload or short circuit. Read its markings and see why two breakers rated at 16 A can behave differently.
Read articleHow long until a circuit breaker trips? Overload and short-circuit simulator
A circuit breaker does not switch off the moment the current exceeds its rating. Run five scenarios, from a kettle to a short circuit, and watch the bimetal strip, the electromagnet and the cable temperature on a time-current chart.
Read articleEarthing systems explained: TN-S, TN-C, TN-C-S, TT and IT
An earthing system describes how the supply, earth and metal appliance enclosures are connected. The key question: which path does current take back to the source when insulation fails?
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Planning
How a home is split into circuits
Why lighting and sockets never share a breaker, how many points belong on one line, and how the app groups rooms into circuits.
Read articleAppliances that need their own circuit
Stove, oven, water heater, EV charger and the rest: why each gets a dedicated line, and what breaks when they share a socket circuit.
Read articleHow total load is calculated
Room estimates plus appliance nameplates, corrected by a demand factor, checked against the main breaker.
Read articleBalancing loads across three phases
A 3×25 A supply is not one 75 A pool: each phase has its own limit, and skewed loads trip breakers.
Read articleCable cross-sections explained
Why 1.5 mm² pairs with B10 and 2.5 mm² with B16, and why oversizing the breaker is the most dangerous DIY mistake.
Read articleWhy leave spare space in the panel
Households grow: an EV charger or a garden line will arrive sooner than you think. The 20–30% rule keeps upgrades cheap.
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Equipment
RCD types AC, A, F and B: which leakage can they detect?
Two RCDs marked 40 A and 30 mA can provide different protection. AC, A, F or B identifies the residual-current waveforms a device is designed for. Explore the shapes and everyday examples.
Read articleSelective (type S) RCDs in cascades
Without selectivity, a leak in the bathroom trips the main RCD and blacks out the whole home.
Read articleWhat is an AFDD and what does it protect?
A damaged conductor can arc under an ordinary load. An AFDD (Arc Fault Detection Device) detects signs of dangerous electrical arcing and disconnects the circuit, complementing circuit breakers and RCDs.
Read articleSurge protection (SPD): when you need it
Lightning near an overhead line can push thousands of volts into your wiring. An SPD shorts the spike to earth.
Read articleVoltage relays: cheap insurance for appliances
A lost neutral can push 380 V into a 230 V home. A voltage relay disconnects everything before appliances burn out.
Read articleChoosing the panel enclosure
The enclosure decides how many circuits fit, how safe the panel is in a fire and how easy the next upgrade will be. It is the one part that is expensive to change later.
Read articleSolar, generators and battery backup
What changes in a panel when a PV inverter, generator or UPS is present — and why this part always needs a licensed electrician.
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Reading your project
How to read your panel plan
The exported PDF has six parts. Here is what each one shows, and how to read the text single-line diagram, the device labels and the numbered assembly steps.
Read articleHow a panel is wired inside
Busbars, combs and wire sizes: how power is distributed inside the panel and why every neutral must stay within its RCD section.
Read articleHow to read the shopping list
The generated shopping list describes every device by its electrical properties, not by brand. Here is how to decode each line and what you still have to buy yourself.
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Safety
Working safely in a panel
A panel can kill you in the time it takes to change your mind. Isolate at the source, prove it dead, and leave the final connection to a licensed electrician.
Read articleWhen to call an electrician
PlanMyPanel covers typical residential panels. Here is what lies outside that scope — and what always needs a professional.
Read articleRCD keeps tripping: how to find the cause
Overload, short circuit and earth leakage each fail in a recognisable way. Here is how to tell them apart, how to find the guilty circuit, and when to stop and call someone.
Read articleWiring a wooden house safely
In a wooden house the wall itself is fuel. Three extra requirements keep it from becoming kindling.
Read articleEU HD 60364 vs CIS PUE: what the profile changes
A rule profile decides which checks run on your panel and how strict they are. Here is what actually differs between the two.
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