Oil Management Unit

ECS’s Oil Management Unit takes to the road again

Heysham nuclear power station is in Lancashire and is operated by EDF Energy. The site is divided into two separately managed stations, Heysham 1 and Heysham 2. These power stations employ over 1,100 staff and 400 contracting partners.


Heysham 2 generates enough low carbon power for around two million homes from its two advanced gas cooled reactors.


Sometimes we need to ‘switch off’ parts of network for asset maintenance or replacement so the network continues to operate safely and efficiently. EDF took advantage of one of these recent events at Heysham 2 to ask us to review the condition of the oil used within the power station. This routine is a crucial part of ensuring that Heysham remains fully operational and adheres to the highest standards of maintenance and safety. 

Oil management is an important part of asset maintenance – the oil acts as an insulator within oil circuit breakers and transformers, and it is important that it is regularly sampled for contaminants. If the oil isn’t properly managed, after time, electricity and heat create contaminants and begin to degrade the oil, presenting huge safety risks and potentially causing major operational faults.


ECS utilise the highly experienced oil management experts of National Grid Electricity Transmission who operate from a mobile, high-tech Oil Management Unit (OMU) to carry out these services on site. From this unit, they can carry out a vast array of services: from sampling, testing, analysis and advice, to replacement, reconditioning and reclamation. 

Once the OMU had sampled the oil at Heysham 2, the unit transformers were fully flushed, drained and refilled. The new oil used was processed to the exact quality required by EDF, going beyond the ‘correct’ processing standards, ensuring that EDF’s equipment remained in a safe and reliable operating condition. 

EDF were delighted with the work and found the OMU service and equipment to be excellent. They liked the fact that the OMU machinery is available 24/7, as this reduces the time taken for the work to be completed and found our staff to be very helpful and accommodating. 

Peter Starkie (Contract Manager), for EDF commented: 

ECS’s OMU staff worked in conjunction with station and other contractors to achieve the planned results. The staff attending site understood the scope and their interaction within a challenging programme to achieve the end result. 

Douglas Barker (Responsible Engineer), for EDF added: 

We have now had three transformers refilled by the OMU working in conjunction with Shell and a further two transformers reprocessed. The quality of the flushing has been exceptional leading to better than expected results and benefits from the refills. The attention to detail, experience, environmental awareness and attitude of the OMU staff, while working on our nuclear site, has been exactly what we expect. 

If you would like to know more about Oil Management and the standards we work to please contact us at [email protected] or call 0800 783 9228.