A 30 mA RCD per Socket? What AREI Book 1 V06 Says (2026)
A 30 mA RCD is not required per socket or automatically per circuit. Learn what AREI Book 1 V06 says for new and existing domestic installations in Belgium.
Short answer: neither per socket nor per circuit
No. For a new domestic installation, AREI does not require a dedicated 30 mA residual-current device (RCD) for every individual socket. It does not automatically require a separate RCD for every socket circuit either. The requirement concerns protection of the relevant circuits: one high- or very-high-sensitivity RCD can protect several final circuits. In the usual arrangement, its residual operating current is no more than 30 mA.
The choice still depends on circuit types, the protection at the origin and the earthing arrangement. A portable power strip does not change its circuit.
AREI Book 1 V06: the rule for a new installation
This explanation was checked against the local official AREI Book 1 V06. For domestic installations, the main rule is in subsection 4.2.4.3(b). At the origin of the installation, at least one RCD with a residual operating current of no more than 300 mA is installed. Immediately downstream, at least one high- or very-high-sensitivity RCD (maximum 30 mA) protects at least the following groups:
| Circuit or location | What the rule means |
|---|---|
| Socket outlets not intended for fixed appliances | Ordinary socket circuits are connected downstream of the sensitive RCD. |
| Lighting | Lighting circuits are included in a new domestic installation. |
| Rooms with a bath and/or shower | Circuits supplying these rooms are included. |
| Washing machine, tumble dryer and dishwasher | These appliances are expressly named. |
No more than eight final circuits may be connected per such 30 mA RCD. This is a limit on downstream circuits, not on the number of socket outlets. A house with six suitable final circuits can therefore be designed with one 30 mA RCD; splitting three circuits across each of two RCDs can also be a design choice. Splitting can limit the extent of an outage, but AREI does not automatically require a separate RCD for each circuit.
Fixed or fixed-in-position appliances such as a refrigerator, electric cooker or heating installation may, under the stated exception, connect per circuit or group to an additional RCD at the origin. This is not permission to put sockets or lighting behind 300 mA: washing machines, tumble dryers and dishwashers are in the 30 mA list.
Eight socket outlets per final circuit
Subsection 5.3.5.2(b) limits the number of single or multiple socket outlets to eight per final circuit. The rule is therefore about the final circuit, not about installing one RCD per socket.
A multiple socket outlet is the fixed wall-mounted combination with, for example, two or three connection points. A double socket is one multiple socket outlet for the purpose of this counting rule, not a reason to install another RCD. A portable power strip or cable reel cannot be used to bypass the limit: it is plugged into an existing outlet and creates neither an extra circuit nor extra protection.
In certain conditions, sockets, lighting and fixed appliances may share a final circuit. A fixed appliance, or group operated by one common control, is treated as one socket outlet. Appliances requiring their own circuit under 5.2.1.2 remain excluded. The number eight is not a count of every plug used in a home.
What changes above 30 ohms?
The 30-ohm threshold is not an alternative to 30 mA protection. If the earth electrode’s dispersion resistance is higher than 30 ohms, Book 1 V06 requires at least two high- or very-high-sensitivity RCDs for the circuits concerned. Each RCD may contain no more than sixteen single or multiple socket outlets. A fixed appliance, or a group of fixed appliances operated by one common control device, may be treated as one socket outlet for this count.
There is an additional measure. For the circuits covered by the exception for fixed appliances, individual separation transformers and other circuits not included in the 30 mA list, the RCDs installed at the origin must also be supplemented by at least one RCD with a residual operating current of no more than 100 mA per circuit or group of circuits. This is additional protection; 100 mA does not replace the 30 mA protection required for sensitive circuits.
A measurement exactly equal to 30 ohms is not higher than 30 ohms. Have earthing resistance and circuit distribution assessed by a competent person.
Bathroom: 30 mA is not a complete bathroom solution
Circuits supplying a room with a bath and/or shower must, under subsection 7.1.4.3, be protected by one or more high- or very-high-sensitivity RCDs. These devices are installed outside the bathroom. They may also protect circuits in other rooms. Zones 0, 1 and 2, the required degree of protection for equipment and supplementary bonding remain separate subjects. A 30 mA RCD therefore does not automatically make a socket in a prohibited zone acceptable.
Book 1 includes targeted transitions for existing bathrooms and projects begun before 1 March 2025. These are deviations for existing parts, not a rule for a new bathroom; supplying equipment in another room does not remove Chapter 7.1 requirements.
Transition for installations started before 1 June 2023
For existing parts of domestic installations whose on-site execution began before 1 June 2023, subsection 6.5.8.1(1) provides a specific deviation; the pre-use conformity inspection then takes place from 1 June 2023. Subject to that provision’s conditions, the circuits listed in points 1 and 2 may remain in service without the sensitive protection currently required. The deviation can also apply to non-important modifications or extensions to those circuits. It also permits more than eight final circuits to remain behind a sensitive RCD and allows an existing arrangement with one RCD for all lighting and, for each other circuit or group, no more than sixteen single or multiple socket outlets.
This is not an automatic exemption: the existing part, start date and inspection conditions must match. The approved inspection body must be informed and mention the deviation in its report. An important modification may require the RCD at the origin for the whole installation. A new installation or project started after 1 June 2023 cannot use this transition.
No guarantee against power cuts
An RCD trips when it detects residual fault current. That is a safety function, not a promise of uninterrupted power. Leakage, moisture or a defective appliance can cause a trip. Several RCDs may limit consequences, but do not prevent trips or prove compliance.
Draw it, export it, then have it checked
With PlanElec, you can record circuits, RCDs and sockets in the editor, export a PDF and run an orientational self-check. This makes data and open questions more visible; it is not an AREI compliance certificate and does not replace a complete design review, measurements or an official inspection.