Transformer oil treatment

Oil treatment process

Most power equipment is using transformer oil for its dielectric properties for cooling, insulating, and protecting the active parts. Transformer oils are highly refined oils that consist mainly of a mixture of hydrocarbons. Over time, moisture and gas byproducts start to form in the oil. Increases in water content in the oil results in decrease of break down voltage in oil. At this stage oil is losing its dielectric properties because it is getting wet. To prevent further deterioration of oil and possible damage to the active part of the transformer, oil needs to be stripped of water by vacuum treatment. Oil treatment equipment treats oil in steps.

• At the inlet of the equipment, oil is filtered through a coarse filter to prevent any particles from entering the equipment.
• It is then heated to the desired temperature to elevate the vacuum treatment effect. After the oil has been heated, it is then pumped through a vacuum breaking valve into the degassing section where it is dehydrated and degassed.
• Exiting the highly efficient vacuum chamber it is pumped again trough a vacuum breaking valve and into the outlet pump.
• After passing through a fine 0.5-micron filter treated oil is then pushed back to the transformer by the outlet pump.
• This entire process can be repeated many times until the oil is completely stripped of moisture, gasses and other particles.

Before the beginning of the oil treatment process the responsible staff member always carries out an onsite inspection to ensure the accessibility of the transformer and the possibility of connecting of oil regeneration equipment to the transformer.

Number of key factors need to be checked and measured, such as local power source availability, flange sizes for connection, distances from and to the transformer, check valves below the conservator and any other factors that might play a role in the subsequent oil treatment service. After a successful onsite inspection exact dates for connecting and disconnecting of equipment are set. On the date of the connection to the transformer oil treatment equipment is brought onsite and connected to the transformer. The connection process takes several hours to ensure that all safety requirement is fully met. After a successful connection oil treatment process begins. Oil treatment last from hours up to several days depending on the oil contamination but mainly on the total quantity of oil inside the transformer. Once the oil quality inside the transformer has been determined by our staff to be satisfactory the oil is then inspected in a certified laboratory to ensure that it meets the requirement of IEC 60422 standard for mineral insulating oils and equipment is than disconnected from the transformer and moved offsite.

All transformer oil treatment equipment FILOIL operated by Ekofluid is fully automatic controlled by a PLC system and visualized by a SCADA system. Transformer oil treatment equipment is capable of vacuum treatment on all transformer oils and is designed for continuous operation onsite. All units are placed in self-contained enclosures or containers depending on the type of the unit. Each unit is transported by a truck or by a car onsite and it is attached to its own wheel base. The weight of individual units is dependent on the specific unit type. In case of a specific requirement the unit can be lifted of the wheel base and put into a specific position.

The level of water or gasses contamination of transform oil differs from situation to situation. It is therefore very difficult to generalize the starting parameters of treated oil nevertheless regardless of the level of contamination, oil treatment always delivers the result required by the IEC 60422 standard for mineral insulating oils in electrical equipment.

Ekofluid sees safety as one of the key factors to successful oil treatment. It is precisely for this reason our onsite teams are specially trained to operate under strict safety guidelines to ensure maximum safety of all equipment present on site. All our personal is certified according the SCC safety guidelines. In order to maximize safety onsite our oil regeneration and oil treatment devices have implemented numerous safety features to minimize the possibility of risk. Fast closing electrics safety valves on the side of the transformer and on the side of oil treatment equipment ensure that in case of a malfunction the transformer is completely sealed off therefore preventing any leakage of oil into the environment. Manual overheating protection inside the oil treatment equipment ensures that in case of a software malfunction or misuse oil is not overheated and damaged. Entire oil treatment equipment servers as an oil catch pan with level switch inside preventing of any leakage of oil into environment in case of a local malfunction of the unit. Constant monitoring of temperature, flow and vacuum parameters across the equipment ensures that in case of an unforeseen situation the equipment switches itself into a fail-safe mode. It is also very important to note that our personal never leaves the site during the operation of the equipment and therefore all our equipment is under constant supervision during its operation.