For this case, Sea Marconi has done a detailed study using multidetection diagnostic tools from which emerged the following critical factors:

1. PCBs above the threshold due to cross contamination caused by previous treatment performed by unskilled operator in a sensitive environment (water for cultivation)
2. Corrosion C2 (NON DBDS & Corrosive sulfur) with DBDS equivalent = 70 mg/Kg and CCD test result as corrosive without DBDS
3. corrosion C4 (NON sulfur corrosion & metal dissolution), due to presence of copper in organ metallic form
4. dielectric properties of oil non standard

there are no electrical faults, there are thermal defects but only a normal aging of the insulation solid

Sea Marconi proposed and performed and integrated treatment based on selective depolarization (Chedcos) and dehalogenation of PCB in oil (CDP Process). The treatment was performed on-site and on-load (transformer in service and under load) with a total duration of 22 days, of which 16 for the treatment part.

The solution Sea Marconi won and convinced primarily for the modularity of the treatment unit (DMU), with reduced weight and size and therefore extremely easy to handle in an area with extreme logistical constraints.
Not only, the service Sea Marconi was able to heal, with just one treatment, the problems of corrosivity and the problems of PCB contamination, both the poor dielectric oil.

The brilliant results achieved are the result of a mix of excellence:

• Innovation and technical treatment plants and transformer oil,
• the use of specific reagents patented,
• the competence of technicians Sea Marconi,
• certification of the analytical test results

This case brings together a number of peculiarities that make it unique worldwide. It has required a major effort to research, development and innovation. This has generated a series of advanced methodologies focused to multidetection; moreover this case has allowed us to study new treatment methodologies and instrumental configurations for monitoring entirely new.

Since this case is expected to publish some results in trade magazines from IEEE and Analitcal chemistry.

Selective depolarization treatment (Chedcos) in order to remove corrosive sulfur compounds and dehalogenation treatment (CDP Process®) in order to remove the PCBs from oil and transformer. The treatment was performerd on-site and on-load (transformer in operation and fully load during the treatment).

*The agreed guarantee was PCBs < 40 [mg/Kg]

Hydro power plant with 3 GSU transformers

Nameplate data of the transformer:

Manufacturer: xxx
Year: 1965
Power [MVA]: 80
Voltage [KV]: 220
Oil mass [Kg]: 35.000
Oil type: naphthenic blended

Selective deplarization treatment (Chedcos) in order to remove the corrosive sulfur compounds and dehalogenation treatments (CDP Process®) in order to remove the PCBs from the oil and the transformers. the tratments were performed on-site and on-load (transformer in service and fully load during the treatment).

*The agreed guarantee was PCBs < 50 [mg/Kg]

Selective depolarization treatment (Chedcos) in order to remove the corrosive sulfur compounds and dehalogenation treatments (CDP Process®) in order to remove the PCBs from the oils and transformers. the treatments were carried out on-site and on-load (transformer in service and fully load during the treatments).

*The agreed guarantee was PCB < 50 [mg/Kg]

Il trattamento con terre follari (NON da Sea Marconi) non ha prodotto alcun risultato contro lo zolfo corrosivo

Trattamento di depolarizzazione selettiva (Chedcos) per la rimozione dei composti solforati (NON DBDS) responsabili della corrosione.

Centrale thermique avec 8 transformateurs élévateurs

Caractéristiques techniques des transformateurs :

Constructeur : xxx
Puissance [MVA] : 370
Tension [KV] : 400
Masse d’huile [Kg] : 58.000
Type d’huile : huile mélangée

Août 2011 : Panne avec explosion et incendie

Diagnostic, pronostic avec recommandation d’effectuer le traitement de dépolarisation sélective (Chedcos) pour l’élimination des composés sulfurés (NON DBDS) responsables de la corrosion.

The diagnosis in the 2009 showed:

Total sulfur = 200 mg/Kg
TCS (Total Corrosive Sulfur) = 157 mg/Kg (DBDS eq.)
CCD Test = corrosive
IFT = 19 mN/m
DBTP = 38 mg/Kg

Failure in the 2013

Sea Marconi recommended the selective depolarization treatment (Chedcos) in order to remove the sulfur compounds (NOT DBDS) responsable for the corrosion.