Inventorying is a systematic activity focused on collecting strategic information on resources to be managed (asset management) during their life cycle (LCM) in a given geographic area, in a defined time frame, for economic-financial, technical-operational, social and environmental (e.g. PCB criticality), etc. purposes.

The inventory defines the perimeter of competence and responsibility for the holder and the appointed individuals, from the beginning of the transformer's operating life on site until the end of its operational life, which coincides with de-energisation and subsequent sale or disposal as waste, in accordance with local laws or regulations.

In particular, for PCB-contaminated equipment, the obligations imposed by the following must be complied with:

European Council directives (96/59/EC – Best Available Techniques, 96/61/EC – Best Environmental Practices 2001/68/EC)

Stockholm Convention on POPs

other standards (IEC 60422 Ed.4-2013, CENELEC CLC/TR 50503 February 2010, CIGRE 413 April 2010).

[ALT img:Inventory management (data collection and updating)]

It is good practice to create and update the inventory of one's machine and oil pool to better manage any functional criticalities (equipment type, year, builder, oil type, power, voltage, etc.) or environmental criticalities (e.g. prevention of significant incidents such as explosion and fire, etc.), without neglecting factors of environmental severity, important for assessment of asset management and risk assessment.

REAL EXAMPLE (click to open)

With the information obtained from a detailed and constantly updated inventory, it is possible to outline the following scenario (with the necessary countermeasures).

In a 500 KV electric transmission system with 250 transformers and shunt reactors (average age 25 years), an increase in the frequency of failure was observed, rising from 1.8% to 2.1% a year in the last three years; at the same time, a failure rate of 17.5% a year was observed on the new replacement transformers.There is a clear need to redefine strategic management guidelines and replacement of equipment.In particular, it is necessary to redefine:

• requirements for the purchase of machines and oils,
• procedures for their acceptance,
• factory test and
• commissioning procedures
• as well as maintenance and operation practices.

Sea Marconi supports owners in the creation and updating of the inventory of the machine pool through:

• identification of transformers and oils with their geographical location (assignment and site) and their labelling
• collection and entering of data (owner, plate data, reference and/or replacement vlaue, etc.) in the Sea Marconi database or other suitable instrument
• analysis of data analysis with classification of transformers by families and categories (e.g.IEC 60422 tab. 2[3])
• systematic updating of strategic information, dynamically displaying case history data, signs (from visual inspection) and symptoms analysed (indicators)

Advantages

The inventory is an instrument for knowing and effectively managing the transformer and oil pool (asset management) with a view to loss prevention and environmental protection.

Regulatory references

CENELEC CLC/TR 50503:2010 Guidelines for the inventory control, management, decontamination and/or disposal of electrical equipment and insulating liquids containing PCBs

UNEP Manuals on PCBs – http://www.chem.unep.ch/pops/newlayout/repdocs.html

Stockholm Convention:Training Tool on the Technical Guidelines for the Environmentally Sound

Management (ESM) of Persistent Organic Pollutants (POPs) wastes http://chm.pops.int/Portals/0/flash/popswastetrainingtool/eng/index.html

Basel Convention:Technical Guidelines:Technical guidelines for the environmentally sound management of wastes consisting of, containing or contaminated with polychlorinated biphenyls (PCBs), polychlorinated terphenyls (PCTs) or polybrominated biphenyls (PBBs).http://www.basel.int/pub/techguid/tg-PCBs.pdf