05
RCD-Protected Socket Circuit
Add earth fault protection to a socket outlet using an RCD. This is mandatory in bathrooms, kitchens, and outdoor circuits in modern installations.
Components Needed
Text Wiring Path
Live → MCB → RCD (L-in→L-out) → Socket (L) Neutral → RCD (N-in→N-out) → Socket (N) Earth → Socket (E)
Schematic
Steps
- 1Place Live, Neutral, and Earth terminals.
- 2Place an MCB and wire Live → MCB.
- 3Place an RCD. Wire MCB output → RCD L-in. Wire Neutral → RCD N-in.
- 4Place a 3-Pin Socket.
- 5Wire RCD L-out → Socket L.
- 6Wire RCD N-out → Socket N.
- 7Wire Earth terminal → Socket E.
- 8Press Run — the socket is live and protected by both the MCB and RCD.
Key insight
The RCD monitors the difference between Live and Neutral current. Any leakage (e.g. through a person to earth) causes an imbalance and trips the RCD in under 40ms — far faster than an MCB and before lethal harm can occur.
⚠ Safety practice
This circuit relies on its protective earth and RCD. In practice, confirm the RCD trips with its test button after installation, and never lift the earth — it is the path that clears a fault instead of your body.
Terms used here
Defined in the glossary — each one opens at its own entry.
Ready to try it? This walkthrough matches a built-in guide — open it pre-built in the editor.Build this circuit →
Now wire it for real.
Build this circuit in the browser, inject a fault, and watch the protection respond.