Many proud electrical asset managers will proclaim that their fleet of transformers is PCB-free, yet although they have worked long and hard to achieve this outcome some PCB oil still resides in their system. In our experience most electric utilities in Australia have methodically surveyed their transformer fleet (power transformers anyway) and maintain dedicated registers including transformer technical data, nameplate information, purchase and warrantee details, and importantly a history of oil analysis results with PCB levels noted.
PCB levels above 2ppm (parts per million) (also reported as 2mg/kg (milligrams per kilogram)) are defined to be PCB contaminated for the sake of handling, movement and disposal requirements. A line must be drawn in the sand somewhere, and this is it. Hence a transformer reported at 1.9ppm PCB would be considered “PCB-free” and not subject to the onerous requirements of PCB oil disposal.
In our experience the prevalence of PCB contaminated transformers and equipment is certainly on the decrease, and in general where we do find PCB levels above the threshold of 2ppm they are typically below 50ppm and mostly in the band between 2 and 10ppm. Regardless, PCB transformer oil that is reported as 3ppm may as well be 49ppm as the same process for its end of life must be followed.
When presented with an enquiry to “please price to dispose of our redundant transformer”, our first line of questioning is to ask if you can provide: • A picture of the nameplate • A picture of the transformer • A copy of the last oil test results
We ask these questions to streamline the process and to be able to price the job as accurately and quickly as possible. Very often a few quick pictures captured on a mobile phone can be texted or emailed to Benzoilon the spot. When this is not possible, we can send a qualified technical representative to attend site to get the necessary details.
A picture of the nameplate Gives us critical information about the age, manufacturer, weight, size, oil volume and internal metallurgy. We need to know these things in order to consider transport from site and potential recoverable materials.
A picture of the transformer Also assists in providing information related to lifting, handling, transport and possible preparatory work needed (depending on size), e.g. bushing removal, de-oiling. It is important to understand the surrounds at the site and access for trucks and lifting equipment. Often the site itself will make a forklift, crane, or the lifting machine available.
A copy of the latest oil test results Hopefully PCBs were tested for and are reported on a NATA accredited lab report. If the report just details oil dissolved gas analysis (DGA) or other parameters and not PCB then we would offer to sample the oil and test as needed. Armed with the pertinent details, we can now consider what is needed to safely and professionally perform the job comprising PCB oil disposal.