Oil filtration of twelve 4.8 MVA transformers to 60 kV BDV

Twelve 380 V / 33 kV transformers filtered on site until the oil held 60 kV breakdown voltage.

Insulating oil in twelve 4.8 MVA, 380 V / 33 kV transformers was filtered and dried on site rather than replaced. Each unit was processed until the oil sample reached a breakdown voltage of 60 kV, verified by BDV test before hand back.

Filtration recovers dielectric strength by removing water and particulate contamination, which is a fraction of the cost of new oil and avoids the disposal problem that comes with it.

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