Scenario
Company involved in production of primary aluminum with 8 rectifiers transformers
Nameplate data of the transformers:
Transformer: rectifier, ODAF with membrane
Manufact: xxx
Year: 1998
Power [MVA]: 93,4
Voltage [KV]: 66
Oil mass [Kg]: 27.200
Oil type: naphthenic
Step 1
First failure with discharges of high energy (D2)
Step 2
Post failure analysis, oil fingerprint with identification ant quantification of the copper sulphide on enameled contacts
Step 3
Sea Marconi expertise recommended the selective depolarization treatment (Chedcos)
