Do I Need a 30mA RCD for Every Socket?
No — but you need one per circuit. Learn what the AREI/RGIE requires and when a 30mA residual-current device is mandatory.
No — but every socket circuit needs one
A common misconception: you do not need a dedicated 30mA RCD (residual-current device, or différentiel / differentieelschakelaar) for each individual socket. The AREI/RGIE requirement applies to circuits, not individual connection points. A single 30mA RCD typically protects multiple sockets connected to the same circuit.
What does the AREI say?
The AREI (General Regulations on Electrical Installations) specifies in several articles when 30mA differential protection is mandatory:
| Article | Requirement |
|---|---|
| Art. 4.2.4.3_b | All socket circuits ≤ 32A must be protected by a 30mA RCD |
| Art. 4.2.4.3_b | Maximum 8 final circuits per RCD |
| Art. 7.1.4.3 | In bathrooms (rooms with bathtub/shower), 30mA protection is always mandatory (Chapter 7.1) |
Key limits at a glance
| Criterion | Limit |
|---|---|
| Max. circuits per 30mA RCD | 8 |
| Max. sockets per circuit | 8 (mandatory per Art. 5.3.5.2_b) |
| Rated current for socket circuits | 16A or 20A |
| Min. cable cross-section at 16A | 2.5 mm² |
Practical example
A typical single-family home might have 6 socket circuits. These can be split across two 30mA RCDs:
- RCD 1 (30mA, Type A): Living room, hallway, bedroom 1 sockets — 3 circuits
- RCD 2 (30mA, Type A): Kitchen, bedroom 2, office sockets — 3 circuits
This way, if one RCD trips, the entire house doesn't lose power, and you stay within the 8-circuit limit per RCD.
Warning: For bathrooms (Art. 7.1.4.3), the AREI prescribes special protective measures. In residential installations (Art. 4.2.4.3_b), circuits in rooms with a bathtub and/or shower must be protected by a high-sensitivity residual-current device (30 mA).