Electrical Installation Inspection

REBT ITC-BT-17 and EN 61439 specify requirements for distribution boards including minimum circuit protection, RCD sensitivity, and MCB ratings. Each dwelling must have a general distribution board (CGMP) with a main switch, RCD protection (30 mA for socket circuits), and individual MCBs for each circuit. The board must be installed at a height between 1.4 m and 2.0 m per ITC-BT-17.

1. Verify the distribution board location and mounting height — between 1.4 m and 2.0 m from floor level per ITC-BT-17

2. Check that the main switch (IGA — Interruptor General Automatico) rating matches the contracted power supply

3. Verify RCD (diferencial) protection — 30 mA sensitivity for all socket circuits, correctly rated for load per ITC-BT-25

4. Confirm each circuit has individual MCB protection with correct rating matching cable size per REBT Table 1 ITC-BT-19

5. Check that circuit labelling is clear, accurate, and permanent per EN 61439

6. Verify adequate spare capacity in the board for future circuits (minimum 20% spare ways recommended)

- RCD sensitivity incorrect — 300 mA used where 30 mA is required for socket circuits

- MCB rating exceeds cable current carrying capacity creating fire risk

- Circuit labelling missing or inaccurate

- Distribution board overfilled with no spare capacity for modifications

REBT ITC-BT-19 and IEC 60364-5-52 specify cable sizing based on current carrying capacity, voltage drop, and short-circuit rating. Maximum voltage drop is 3% for lighting circuits and 5% for power circuits per REBT. Cable types must comply with EN 50575 for fire performance. CTE DB-SI requires cables in evacuation routes to be Class B2ca-s1,d1,a1 or better.

1. Verify cable type and cross-section match the design — minimum 1.5 mm2 for lighting, 2.5 mm2 for socket circuits per ITC-BT-25

2. Check voltage drop at the most distant point — maximum 3% for lighting, 5% for power circuits per REBT

3. Confirm cable fire classification meets CTE DB-SI requirements — minimum Cca-s1b,d1,a1 general areas, B2ca-s1,d1,a1 for evacuation routes

4. Verify cables are installed in approved conduit, trunking, or cable tray per ITC-BT-20 and ITC-BT-21

5. Check that cable bending radii comply with manufacturer specifications (typically minimum 6x cable diameter)

- Cable cross-section undersized for the circuit load and length causing excessive voltage drop

- Cable fire classification not meeting CTE DB-SI requirements for the installation location

- Cables installed without conduit protection where required by REBT

- Excessive cable bunching reducing current carrying capacity without derating applied

REBT ITC-BT-18 and IEC 60364-5-54 require a comprehensive earthing and bonding system. Earth electrode resistance must not exceed 37 ohms (for 30 mA RCD systems) to ensure disconnection within the required time. All exposed conductive parts and extraneous conductive parts must be bonded to the main earthing terminal. Supplementary bonding is required in bathrooms per ITC-BT-27.

1. Measure earth electrode resistance — must not exceed 37 ohms for installations with 30 mA RCD per REBT ITC-BT-18

2. Verify continuity of protective conductors (earth wires) from the distribution board to every socket, switch, and equipment point

3. Check main equipotential bonding connections to metallic services: water, gas, structural steel per ITC-BT-18

4. Verify supplementary equipotential bonding in bathrooms connecting all metal fittings and pipes per ITC-BT-27

5. Confirm earth conductor sizes comply with REBT Table 2 ITC-BT-18 — minimum 2.5 mm2 with mechanical protection, 4 mm2 without

- Earth electrode resistance too high, especially in dry or rocky soils

- Main bonding connections to metallic services omitted or disconnected

- Supplementary bonding missing in bathrooms creating electric shock risk

- Protective conductor continuity broken at junction boxes

REBT ITC-BT-25 specifies minimum circuit provisions for dwellings based on electrification level (basic or elevated). Basic electrification requires minimum 5 circuits: C1 (lighting), C2 (general sockets), C3 (cooker/oven), C4 (dishwasher/washing machine), C5 (bathroom sockets). Each circuit has maximum point limits and specific cable sizes per ITC-BT-25.

1. Verify the number of circuits meets REBT ITC-BT-25 minimum requirements for the electrification level

2. Check that the number of points per circuit does not exceed ITC-BT-25 limits (e.g. maximum 20 sockets per C2 circuit)

3. Confirm socket outlet positions comply with CTE DB-SUA — minimum heights and distances from water sources in bathrooms per ITC-BT-27

4. Verify dedicated circuits for high-power appliances (cooker, hob, electric heating) per ITC-BT-25

5. Check socket outlets are correctly wired — live, neutral, and earth in correct terminals with secure connections

- Too many sockets on a single circuit exceeding ITC-BT-25 limits and causing overloading

- Missing dedicated circuits for high-power appliances

- Socket outlets installed in prohibited zones in bathrooms per ITC-BT-27

- Earth connection missing from individual socket outlets

CTE DB-SI Section SI 1 requires all cable penetrations through fire-rated walls and floors to be sealed with fire-stopping materials to maintain the fire compartment rating. Fire stopping products must be tested per EN 1366-3 (penetration seals) and achieve the same fire resistance as the element they pass through. Cable tray and conduit penetrations require specific tested solutions.

1. Identify all cable penetrations through fire-rated walls and floors — check against the fire compartmentation drawings

2. Verify that each penetration is sealed with a tested fire-stopping system per EN 1366-3 matching the required fire rating

3. Check that the fire-stopping product is correctly installed per the manufacturer's tested configuration — correct depth, backing material, and fill

4. Confirm fire-stopping labels or identification marks are visible at each sealed penetration for future inspection

5. Verify that cable bundles through fire stops do not exceed the maximum fill ratio of the tested configuration

- Cable penetrations through fire walls left unsealed or filled with non-fire-rated material

- Fire-stopping product installed incorrectly — wrong depth or missing backing material

- Additional cables added through existing fire stops without re-sealing

- Fire-stopping identification labels missing making future inspection difficult

CTE DB-SUA Section SUA 4 and CTE DB-HE Section HE 3 establish requirements for interior lighting levels and energy efficiency. Emergency lighting must comply with EN 1838 and REBT ITC-BT-28 — minimum 1 lux at floor level on escape routes, 5 lux at safety equipment. Emergency luminaires must provide 1 hour minimum autonomy and activate within 5 seconds of mains failure.

1. Measure illuminance levels with a lux meter and verify compliance with CTE DB-SUA Section SUA 4 minimum values for each area type

2. Check emergency lighting positions — required at exits, direction changes, stairways, and near fire equipment per CTE DB-SUA

3. Verify emergency lighting achieves minimum 1 lux on escape routes and 5 lux at safety signs per EN 1838

4. Test emergency lighting operation — simulate mains failure and confirm activation within 5 seconds and 1 hour minimum autonomy

5. Confirm lighting power density does not exceed CTE DB-HE3 limits (VEEI values) for energy efficiency compliance

- Emergency lighting fails to activate or has insufficient autonomy due to battery degradation

- Illuminance levels below CTE DB-SUA minimums in corridors and stairways

- Emergency lighting not installed at required positions (changes of direction, exit doors)

- Lighting energy consumption exceeds CTE DB-HE3 limits

REBT ITC-BT-05 and IEC 60364-6 require completion testing and verification of all electrical installations before energisation. Tests include continuity of protective conductors, insulation resistance (minimum 0.5 MOhm at 500V DC), earth fault loop impedance, RCD operation (trip time and current), and polarity verification. An authorised installer must issue the Installation Certificate (Boletin).

1. Verify continuity of all protective (earth) conductors — resistance should be less than 1 ohm per IEC 60364-6

2. Measure insulation resistance between live conductors and earth — minimum 0.5 MOhm at 500V DC per REBT

3. Test earth fault loop impedance at the most distant point of each circuit — verify disconnection time per IEC 60364-4-41

4. Test all RCDs — trip time must not exceed 200 ms at rated current (30 mA), and 40 ms at 5x rated current per IEC 61008

5. Verify correct polarity at all outlets, switches, and connection points

6. Confirm the Installation Certificate (Boletin Electrico) has been issued by the authorised installer and registered with the autonomous community

- Insulation resistance below minimum due to cable damage or moisture ingress

- RCD trip times exceeding maximum limits indicating device fault

- Earth fault loop impedance too high for automatic disconnection within required time

- Installation Certificate not obtained or registered delaying occupancy permit

- Polarity reversed at individual outlets despite correct feed