Network maintenance efforts are focused on four main priorities: the safety of people and property, maintaining system performance levels (electricity security and quality), respect for the environment and sustainable use of resources.

To meet these challenges, RTE has adopted a maintenance management system, based on:

• a set of policies setting technical and economic objectives;
• methods, organizational arrangements and internal and external skills and competencies for putting these policies into practice;
• multiannual technical and economic forward planning of maintenance actions;
• experience review in a range of areas (technical, quality, environment, economic, etc.), to enhance and improve the management system's effectiveness.

Ongoing maintenance

RTE has extended a preventive maintenance approach known as RCM (reliability-centred maintenance) to all its installations. This approach has long been used in the aerospace industry. It involves taking preventive action to deal with latent or observed anomalies, by combining different codified maintenance operations, which are carried out in a graduated way at regular intervals.

These include:

• light operations (visual inspections, simple functional tests performed remotely) carried out either monthly or every few months,
• more complex operations (replacing worn parts and refurbishing) carried out every few years.

Many of these operations are carried out under "live line" conditions, where the current in the infrastructure is not shut off before work begins.

Refurbishing

Usually based on short-term programmes, these relatively complex operations are intended mainly to reduce to effects of the weather or environmental conditions on infrastructures. These effects include major or irreversible deterioration in lines or electric substations, which could compromise their operation (e.g. painting metal pylons, replacing high voltage equipment, etc.).