IN-SERVICE OIL ANALYSIS – ESTER LIQUID ESSENTIALS
Hosted by: Transformers Academy
Designed for end users, asset managers and operational stakeholders responsible for ester-filled transformers, this technical session focuses on the correct approach to analysing in-service ester transformer liquids.
Testing ester transformer fluids isn’t a like-for-like substitute for testing conventional mineral oil - and misapplying conventional methods can sometimes lead to confusing or even “alarming” results that are, in fact, completely normal.
Understanding the fundamental chemical and electrical differences between conventional mineral oils and ester liquids is key to correctly interpreting test data and maintaining transformer health.
In this session, experts from Shell MIDEL’s Technical Team are joined by VPS Power - specialists in transformer fluid testing with over 40 years of experience - to share essential guidance on best practices and what to expect when testing in-service esters.
What we’ll cover:
- The importance of applying proper testing protocols
- Mineral oils vs. esters: Key differences in sampling and test setup
- Making sense of results: Interpretation and expectations
About the author
Rosie Lawton
Applications Scientist at Shell MIDELRosie has spent the past four years providing technical support to customers regarding the chemistry of these liquids and their compatibility with other materials. Rosie holds a PhD in Tribology and a Master’s degree in Chemistry, bringing a strong scientific background that bridges the gap between research and application. Rosie is passionate about advancing sustainable and high-performance solutions in the industry. She is especially passionate about educating customers—helping them understand the science behind the product and how to effectively interpret test results.
James Robinson
Business Manager at VPSJames is a highly experienced leader with over 30 years in the sampling and laboratory testing sectors of the oil, gas, and chemical industries. Specialising in electrical insulating oils, he currently serves as Business Manager at VPS Power Ltd, where he leads the sampling, testing, and advisory services operations. James is also an active member of the BSI Gel 10 technical panel for fluids in electrotechnical applications, who are responsible for the UK input into International Technical Committee IEC/TC10 which prepares standards, revisions and amendments for product specifications, test methods, maintenance and use guides for liquid and gaseous dielectrics; for lubricants and control fluids for steam turbines, generators and control systems.
Previously, James spent nearly two decades at one of the largest international testing, inspection, and certification companies, rising to the role of Branch Manager. There, he managed a team of >70 staff and oversaw the transmission electrical insulating oils contract. His career began as a laboratory chemist and evolved through technical and operational leadership roles.
Naheed Umarji
Customer Services Manager at VPSNaheed is an experienced Customer Services Manager with a strong foundation in Applied Chemistry (BSc Hons)and a diverse background spanning laboratory research, risk management, and technical consultancy. Her early career involved working in testing and research laboratories before transitioning into risk management, where she focused on critical asset failures for both government departments and the rail sector. Naheed joined VPS Power as a Technical Advisor and has since expanded her role to include account management and business development, leveraging her technical expertise to support client success. She is a trained auditor for ISO 9001 and ISO 14001, bringing a structured and quality-focused approach to her work.
Ryan Burgess
Technical Manager at VPSRyan is a dedicated technical professional with over 15 years of experience in the testing and interpretation of electrical insulating oils. As Technical Manager at VPS Power, he plays a pivotal role in quality management, method development, client consultation, and data interpretation in line with IEC and IEEE standards. He also serves as the local quality manager, ensuring full compliance with ISO 17025. Before joining VPS Power, Ryan spent over a decade at one of the world’s leading testing, inspection, and certification companies. There, he advanced from Chemist to Laboratory Supervisor and Technical Advisor, managing product testing and client reporting across a broad spectrum of oil types and international standards.