Guide

Top 10 AREI Violations: Identify, Avoid and Fix Them

Which AREI violations are most frequently found during electrical inspections in Belgium? This guide presents the top 10 with AREI articles, solutions and typical costs.

Published on 20 June 2026 8 min min read

Top 10 AREI Violations: Identify, Avoid and Fix Them

During electrical inspections in Belgium, the same violations come up again and again. Around 40% of all inspections come back negative — and the reasons are often the same. In this guide, we present the ten most common AREI violations, explain why they are a problem and show how to fix them.


1. Missing or Incorrect RCD (Residual Current Device)

AREI Article: Art. 4.2.4.3 (main RCD) / Art. 4.2.4.3b (30 mA group RCD obligation)

Description

The single most common deficiency: a missing or incorrectly rated RCD (residual current device, also known as a differential switch). The AREI requires that most final circuits (in particular sockets, lighting, bathroom, washing machines/dishwashers) must be protected by a 30 mA RCD.

Why It's a Problem

The RCD is the most important personal protection device in an electrical installation. It detects fault currents (e.g. when current flows through the human body) and disconnects within milliseconds. Without RCD protection, there is a risk to life in case of insulation faults.

How to Fix It

  • Retrofit a 30 mA RCD (Type A) for most circuits. For EV charger and PV with transformerless inverter, Type B (or equivalent) is required — Type A alone is not sufficient for all circuits.
  • Maximum 8 final circuits per 30 mA RCD (AREI Art. 4.2.4.3b)
  • Additionally: 300 mA main RCD (Type A-S, selective) as main protection

Typical Costs

EUR 100-200 per RCD (material + installation by electrician)


2. Missing or Outdated Electrical Plans

AREI Article: Art. 9.1.2 Nr. 1 (single-line diagram), Art. 9.1.2 Nr. 2 (situation plan)

Description

The AREI requires a current single-line diagram and situation plan for every electrical installation. Often these plans are completely missing or don't reflect the current state of the installation — for example because circuits were added or modified after construction.

Why It's a Problem

Without current plans, neither the inspector nor an electrician can safely assess the installation. In emergencies (fire, accident), the documentation showing which switch supplies which area is missing.

How to Fix It

  • Create or update the single-line diagram and situation plan
  • Document all circuits, breakers, RCDs and consumers
  • Plans must show the actual current state

Typical Costs

EUR 150-400 with an electrician — or free with PlanElec


3. Faulty Earthing

AREI Article: Art. 4.2.3

Description

Earthing is the safety net of the electrical installation. An earth resistance above 30 Ohm — the regulatory threshold per Art. 4.2.4.3b, above which stricter requirements apply (including at least two 30 mA RCDs, max. 16 sockets per RCD) — or completely missing earthing is a severe deficiency. Loose connections or corroded earth conductors are also flagged.

Why It's a Problem

Without functioning earthing, metal enclosures can be live without the RCD tripping. This creates an invisible death trap.

How to Fix It

  • Have the earth resistance measured
  • If >30 Ohm: install additional earth electrodes or renew existing ones
  • Check all earthing connections and tighten if necessary
  • Inspect the earth conductor for corrosion

Typical Costs

EUR 200-500 (depending on work needed for new electrodes)


4. Missing Main Switch

AREI Article: Art. 5.3.5.1b (main load-break switch)

Description

Every electrical installation must have an all-pole main switch that can de-energise the entire installation. The main switch must be rated at least 40A (for standard dwellings).

Why It's a Problem

In an emergency, the entire installation must be switchable off with a single action — for example in case of fire, flooding or accident. A missing main switch can cost life-saving seconds.

How to Fix It

  • Install an all-pole main switch of at least 40A before the first RCD
  • The switch must be easily accessible (distribution board)
  • For three-phase installations: use a 4-pole main switch

Typical Costs

EUR 80-150 (material + installation)


5. Bathroom Zones Not Respected

AREI Article: Art. 7.1

Description

The AREI defines protection zones in the bathroom (Zone 0, 1, 2 and 3), in which only certain electrical devices are permitted. Common violations: sockets in Zone 0 or 1, missing splash protection, switches too close to the bathtub or shower.

Why It's a Problem

Water and electricity are a deadly combination. Bathroom zones ensure that electrical devices maintain a sufficient safety distance from water sources.

How to Fix It

  • Relocate sockets and switches outside Zone 0 and 1 (minimum 60 cm from bathtub/shower)
  • In Zone 2: only IPX4-rated devices (splash protection)
  • Protect all bathroom circuits with a 30 mA RCD
  • No junction boxes in Zone 0 or 1

Typical Costs

EUR 200-600 (depending on scope of relocation)


6. Cable Cross-Section Too Small for the Breaker

AREI Article: Art. 4.4.1 (overcurrent protection) / Art. 5.2.1.2 (cable selection)

Description

The circuit breaker (MCB) must match the cable cross-section. A common mismatch: a 20A breaker on a 1.5 mm² cable (which is only rated for 16A). The breaker then fails to protect the cable from overload.

Why It's a Problem

When a cable carries more current than it can handle, it heats up and can cause fires. The breaker must always be less than or equal to the cable's current carrying capacity.

How to Fix It

Cable cross-sectionMax. fuse (gG)Max. circuit breaker
1.5 mm²10A16A
2.5 mm²16A20A
4 mm²20A25A
6 mm²32A40A
10 mm²50A63A
  • Reduce the breaker to the correct value or
  • Replace the cable with a larger cross-section

Typical Costs

EUR 20-50 (breaker swap only) to EUR 200-500 (cable replacement)


7. Too Many Circuits Per RCD

AREI Article: Art. 4.2.4.3b (max. 8 final circuits per 30 mA RCD); Art. 5.3.5.2b (max. 8 sockets per final circuit)

Description

The AREI limits the number of circuits per 30 mA RCD to maximum 8. In older installations, all circuits often hang off a single RCD.

Why It's a Problem

When too many circuits are connected to one RCD, the probability of nuisance tripping increases (due to cumulative leakage currents). Additionally, a fault leaves the entire dwelling without power — not just the affected area.

How to Fix It

  • Install additional 30 mA RCDs
  • Distribute circuits logically (e.g. by floor or function)
  • Maximum 8 circuits per 30 mA RCD

Typical Costs

EUR 100-200 per additional RCD


8. Missing Circuit Labelling

AREI Article: Art. 3.1.3.1 (identification of circuits)

Description

All breakers and RCDs in the distribution board must be clearly labelled. The labelling must indicate which room or appliance is supplied by the respective circuit.

Why It's a Problem

Without labelling, the correct circuit cannot be quickly switched off in an emergency. Clear identification is also essential for maintenance work.

How to Fix It

  • Apply readable labels to all breakers
  • Name by room and/or function (e.g. "Kitchen sockets", "Bathroom lighting")
  • Labelling must match the single-line diagram

Typical Costs

EUR 10-30 (labels and marker — DIY possible)


9. Cables Without Protection

AREI Article: Art. 5.2.2 (installation methods) / Art. 5.2.1.5 (mechanical protection)

Description

Electrical cables must be routed in protective conduit (empty tubes), cable trays or wall chases. Exposed cables without mechanical protection — such as surface-mounted or loose in the basement — are a violation.

Why It's a Problem

Unprotected cables can be mechanically damaged (nails, screws, rodents). Damaged cable insulation can lead to short circuits and fires.

How to Fix It

  • Route exposed cables through cable trays (protective conduit)
  • For surface mounting: use appropriate cable channels
  • Seal wall penetrations with fire-stop collars

Typical Costs

EUR 100-400 (depending on cable quantity and routing method)


10. Missing Surge Protection (SPD) for New Installations

AREI Article: Art. 4.5.1

Description

Art. 4.5.1 generally requires that persons and property must be protected against the harmful effects of overvoltages — according to good professional practice. In practice, an SPD (surge protection device) is required for new installations and substantial extensions. For existing installations, it is recommended but not explicitly required.

Why It's a Problem

Surges from lightning strikes or grid disturbances can destroy sensitive electronics. An SPD safely diverts surges to earth and protects connected devices.

How to Fix It

  • Install SPD Type 2 in the distribution board (after the main switch, before the RCDs)
  • With lightning protection: additionally SPD Type 1
  • Regularly check the SPD status indicator (green = OK)

Typical Costs

EUR 80-200 (material + installation)


Conclusion: PlanElec Detects 8 Out of 10 Violations Automatically

PlanElec's validation automatically checks your electrical installation for the most common AREI violations:

ViolationPlanElec detects?
1. Missing/incorrect RCDYes
2. Missing plansYes (creates them)
3. Faulty earthingNo (physical measurement needed)
4. Missing main switchYes
5. Bathroom zonesYes (with room type "wet")
6. Cable cross-section/breakerYes
7. Too many circuits per RCDYes
8. Missing labellingYes (automatic in diagram)
9. Cables without protectionNo (physical check needed)
10. Missing SPDYes

8 out of 10 of the most common violations are detected before the inspector arrives.


Related articles:

Avoid the most common AREI violations — with PlanElec, create compliant plans and let the validation check your installation automatically. Get started →