Maintenance of electrical cabins is a fundamental activity to guarantee the correct functioning of the systems, the safety of the operators and the continuity of the electrical service.
Types of maintenance
Preventive maintenance
It consists of scheduled interventions to prevent breakdowns or malfunctions.
Includes activities such as visual inspections, tightening connections, cleaning components, and checking safeguards.
Corrective maintenance
Interventions carried out to repair or replace faulty or broken components.
May include replacing switches, transformers, circuit breakers, or other devices.
Predictive maintenance
Use of tools and technologies to monitor cabin conditions in real time (e.g. thermography, vibration analysis).
It allows you to anticipate failures with a data-driven approach.
Main activities
Visual inspections:
check the general condition of the cabin, detecting any signs of wear, damage or accumulation of dust.
Cleaning:
removal of dust, debris and moisture to prevent short circuits or malfunctions.
Checking protective devices:
control and calibration of differential switches, circuit breakers and other protection systems.
Checking the ventilation system:
check that the cooling or ventilation systems are working properly to avoid overheating.
Tests and measurements:
insulation resistance measurement, continuity testing and power quality analysis.
Thermography:
identification of overheating or hot spots using thermographic cameras.
Regulations and standards
Maintenance of electrical cabins must comply with specific regulations such as:
CEI 78-17: Guidelines for the management and maintenance of MT/BT electrical cabins.
Legislative Decree 81/08: Regulations on safety in the workplace, with reference to electrical systems.
Benefits of regular maintenance: - Increased operator safety.
- Reduction of the risk of blackouts or serious failures.
- Greater energy efficiency and reduced consumption.
- Extending the service life of cabin components.
Checklist Manutenzione Cabine Elettriche CEI 78-17
1. Locale Cabina
2. Apparecchiature di Media Tensione (MT)
- Sezionatori:
- Pulizia e controllo visivo degli isolatori.
- Verifica degli interblocchi meccanici ed elettrici.
- Controllo del serraggio dei collegamenti elettrici.
- Interruttori:
- Ispezione visiva per individuare danni o usura.
- Esecuzione di manovre meccaniche di apertura e chiusura per verificarne il funzionamento.
- Controllo della pressione interna (per interruttori con gas).
3. Trasformatori
- Trasformatori in resina:
- Pulizia degli avvolgimenti da polvere e detriti.
- Verifica del funzionamento delle termosonde e delle centraline di controllo.
- Controllo del serraggio dei collegamenti elettrici.
- Trasformatori in olio:
- Ispezione visiva per individuare perdite o segni di deterioramento.
- Controllo del livello e delle condizioni dell'olio isolante.
- Pulizia degli isolatori passanti e verifica della loro integrità.
4. Quadri di Bassa Tensione (BT)
- Verificare l'assenza di surriscaldamenti, decolorazioni o odori anomali.
- Controllare e, se necessario, stringere i collegamenti elettrici.
- Rimuovere polvere e detriti dai componenti interni.
5. Sistemi di Protezione
- Relè di protezione:
- Verifica delle tarature rispetto ai valori di progetto.
- Simulazione dell'intervento per assicurare il corretto funzionamento.
- Controllo dell'efficienza e dell'integrità dei dispositivi di protezione contro i contatti diretti e indiretti.
6. Messa a Terra
- Verificare la continuità dei conduttori di terra.
- Controllare il serraggio e l'assenza di corrosione nei punti di connessione.
7. Documentazione
- Aggiornare le schede con gli interventi effettuati, le anomalie riscontrate e le azioni correttive intraprese.
- Assicurarsi che la documentazione tecnica sia aggiornata e facilmente accessibile.
To ensure effective maintenance of MV/LV electrical cabins, it is essential to follow a detailed checklist that covers all the critical components of the system. The CEI 78-17 standard provides specific guidelines for the maintenance of these cabins, including simplified sheets for MV users, as indicated in Annex C of variant V1.
Here is a general checklist for electrical cabin maintenance:
1. Cabin Room:
General cleaning: Remove irrelevant materials and clean the room.
Ventilation grilles: Check the integrity and clean the grilles.
Safety devices: Check the presence and condition of personal protective equipment and fire extinguishers.
Warning signs: Ensure that safety signs are present and legible.
2. Medium Voltage (MV) Equipment:
Disconnectors:
Cleaning and visual inspection of insulators.
Check mechanical and electrical interlocks.
Check the tightness of the electrical connections.
Switches:
Visual inspection for damage or wear.
Perform mechanical opening and closing operations to check their functioning.
Internal pressure control (for gas switches).
3. Transformers:
Resin Transformers:
Cleaning the windings from dust and debris.
Check the operation of the thermoprobes and control units.
Check the tightness of the electrical connections.
Oil Transformers:
Visual inspection for leaks or signs of deterioration.
Check the level and condition of the insulating oil.
Cleaning the bushings and checking their integrity.
4. Low Voltage (LV) Switchboards:
Visual inspection: Check for overheating, discoloration or abnormal odors.
Tightening: Check and, if necessary, tighten electrical connections.
Cleaning: Remove dust and debris from internal components.
5. Protection Systems:
Protection relay:
Verification of calibrations against design values.
Simulation of the intervention to ensure correct operation.
Protective devices against direct and indirect contact: Checking efficiency and integrity.
6. Grounding:
Electrical continuity: Check the continuity of the ground conductors.
Connections: Check the tightness and absence of corrosion at the connection points.
7. Documentation:
Maintenance sheets: Update the sheets with the interventions carried out, the anomalies found and the corrective actions taken.
Manuals and drawings: Ensure that technical documentation is up to date and easily accessible.
It is important that all maintenance operations are carried out by qualified personnel, in compliance with current regulations, and that each intervention is carefully documented. For further details and specific sheets, it is recommended to consult the CEI 78-17 standard and its variants.
