- ▸The circuit breaker protects the cable. The RCD protects people.
- ▸The SPD protects appliances from surges; the AFDD prevents fires caused by electrical arcing.
- ▸They all work properly only with an earthing system verified by measurements.
Circuit breakers (MCB)
They cut the circuit on overload or short circuit. The basic rule: the breaker is chosen for the cable size, not the appliance. An oversized breaker “never trips”, but lets the cable overheat.
Residual current protection (RCD)
It detects current “leaking” to earth — for example through the body of someone touching a faulty appliance — and disconnects in a fraction of a second. 30 mA RCDs are used to protect people, and current regulations require them on socket circuits. We recommend grouping them by zone, so a fault in one room doesn’t leave the whole house without power.
Surge protection (SPD)
Nearby lightning or switching on the grid can send voltage spikes that destroy electronics: boilers, TVs, routers, smart home devices. An SPD in the panel diverts these spikes to earth before they reach your appliances.
Arc fault detection (AFDD)
A loose contact or pinched cable can cause small arcs that trip neither the breaker nor the RCD, yet can start a fire inside the wall. An AFDD recognises the arc and cuts the circuit. Recommended for bedrooms, children’s rooms and timber-frame houses.
Verified earthing
The RCD and SPD rely on a good earth electrode. Earthing is verified by measuring its resistance, not “by eye”. At the end you receive the measurement report.
Organisation and labelling
- ▸A separate circuit for each big load: hob, oven, water heater, air conditioning.
- ▸A clear label on every breaker, so anyone knows what it switches off.
- ▸Spare room in the panel for future extensions.
This guide is for information only. The exact configuration of a panel depends on the installation, the load and the current regulations.
