Transformer Oil Swap

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Problem

Many existing substations still operate transformers containing Polychlorinated Biphenyls (PCBs), toxic chemicals historically used as coolants and insulators. Although PCB production was banned in the late 1970s, these oils can remain in service and, when burned at high temperatures, can break down into even more harmful compounds. Customers need a safe, documented way to remove and replace PCB oils and dispose of them through certified channels.

Solution

ESE manages the full oil replacement process, including all required safety and compliance documentation. For each job, we issue and receive the correct paperwork, such as an Isolation and Earthing Certificate and a Permit to Work, before starting any on-site activity.

We then drain the existing oil from the transformer and flush the tank with approximately 10% of new oil. This flush oil is removed, and the transformer is refilled with a new cube of oil. The removed PCB-containing oil and flush oil are then passed to our trusted disposal supplier, who holds all necessary certifications to handle and process hazardous materials safely.

Where appropriate, we can also refill the transformer with Midel oil, a biodegradable, fire-safe alternative to standard mineral oil.