The residual-current device, or RCD, is one of the most important protections in a home. It measures whether current is “leaking” — for example through a faulty appliance or when someone touches a conductor — and switches off very quickly. AREI (Book 1, Part 4 — Protective measures) defines which sensitivity is required for each type of circuit.
300 mA versus 30 mA
300 mA (general): is placed at the origin of the installation and mainly protects against fire caused by insulation faults.
30 mA (high sensitivity): protects people against electric shock and is required for wet or higher-risk circuits.
In recent AREI versions, more circuits must be protected by a 30 mA RCD.
Which circuits behind 30 mA?
| Circuit | Required RCD |
|---|---|
| Complete installation (origin) | 300 mA |
| Bathroom — all circuits | 30 mA |
| Laundry room and damp rooms | 30 mA |
| Outdoor sockets | 30 mA |
| Dishwasher, washing machine, dryer | 30 mA |
| Socket circuits (≤ 20 A) | 30 mA |
Practical tips
Test every RCD monthly with the test button (T).
Spread circuits across several 30 mA RCDs so that one fault does not switch off the entire home.
An RCD does not replace a circuit breaker: you need both — the breaker for short circuits and overloads, the RCD for leakage current.
How Voltuno helps
A good distribution of RCDs and circuits starts with a clear diagram. With Voltuno, you draw a correct single-line diagram, position diagram and matching bill of materials in minutes. Our software is built around AREI requirements, so you can work faster and prepare inspections with a clear, complete file.
Please note: this article is a general explanation and not legal advice. Always consult the official, consolidated AREI text (FPS Economy) for the exact obligations and article references.
