Due to the ever increasing cost of base oils FE have
designed mobile transformer oil filtration plants for filtering of
transformer oil to achieve following improvements after filtration as per IS
335-1993 for new transformer oil and IS 1866 for used transformer oil. The
plants are tailor made to mount local vehicles. Capacity ranges from 500
Ltrs/hr. to 5000 Ltrs/hr
Break Down Voltage
- Moisture Content
- GAS Content
- Suspended Particles
- Tan Delta
The plant is suitable for treating transformer oil by first heating it
and then passing it through specially designed filters and then subjecting
it to vacuum treatment which dehydrates and degasifies the oil
About Transformer Oil From Hydrofined Base Stocks :
Transformer Oil or Dielectric Insulation Oil and other oils required for
electrical machinery and installations can be manufactured using hydro
finished base oils of group II +. The base stocks are selected based on
viscosity requirements of the user. In colder countries pour point is also a
critical property for base oil selection.
Transformer Oil (TO) be used for filling the transformer with a primary
objective of providing electrical insulation between the primary and
secondary coils. Dissipation of heat generated during the process is also an
important function. Electrical insulation is favored by high viscosity and
heat dissipation is favored by low viscosity and circulation of fluid. Base
oil viscosity at a compromise level is selected. Viscosity ranges for base
oil slightly defer country to country, generally in the range of 10 to 40
cst. at 400 Degree C. During the service temperature of oil rises to about
60-800 Degree C. Viscosity of oil decreases due to temperature rise.
Transformer has large extended surfaces exposed to atmosphere. The oil
circulates through these tubes and dissipates heat into the atmosphere.
Transformer Oils are very sensitive to contamination by water or dirt and
fibers as there are serious loss electrical properties. Dust particles and
textile fibers absorb moisture and orient in an alignment or bridge to
connected high voltage and low voltage side resulting into Arcing
and dielectric breakdown. While major breakdown are rare and lead to
ultimate failure of machine, formation of small local arcs are common. It
does not cause immediate damage to machine but damages the oil. These small
arcs expose the oil to a very high corona temperature for split second,
resulting into thermal breakdown of oil constituents. Some of these are
gaseous and accumulate in the vapor space within the machine; others
polymerize and settle down forming sludge. Over a period of time excess
accumulation of gases and sludge may lead to serious dislocation of
operation or even explosion. Thermal breakdown and oxidative degradation of
oil could be reduced by incorporation of appropriate low temperature
oxidation inhibitors and additives. Some users insist upon uninhibited
products in some cases oxidation inhibitors are to be blended. Manufacture
of TOs therefore has following process steps.
Brief Decription :
The basic process for the manufacture of transformer oil consists of
processing of Group II + base oils or equivalent mixed with special type of
additives. Mineral Base oil at 650C is first dehydrated filtered through
specially designed filters. The filtered oil is then processed under vacuum
in a de-hydration and filtration system. Transformer oil so produced meets
BIS 335, 1993.
All operations of the plant are fully integrated through a common control
The plant consists of Feed and discharge pumps, Four stage Filtration plant
,Vacuum pumps(1 & 2 stage), 4 no's absorbent column(2 no's as
stand by), Homogenizing tank with recirculation system, all piping, valves
and instrumentation, Feed and Storage tanks, Filling manifold, Thermic fluid
heater, Cooling tower(if required),Air compressor, Complete skid .Plant
designed as per IS 6034 1989
The plant is rated for continuous operation having built-in dust-proof,
control panel, annunciation system, fault indication with various
inter-locking systems, temperature indicator, ammeter, volt meter, flow
meter. A Control panel with safety features for the following is provided :
Testing Equipments :
- High and low level indicators level in degassing chamber.
- Emergency stop for plant.
- Overload cut out.
- Oil draining and filling operation.
- Pressure relief valves.
- Bypass system for absorbent column.
Automation Optional :
- Bdv Oil Testing Kit (Fully Automatic With Micro Processer Printer
Range 0 To 100kv)
- On Line Ppm Measuring Instrument
- Tan Delta Instrument
- Resistivity Measuring Instruments
Entire process controlled up to homogenization and filling by a
microprocessor/microcontroller PLC based system. Provision to control full
system from the display unit. High contrast color HMI touch screen system.
Inbuilt memory for storage of data. On line PPM meter. Digital flow meter.
External pen drive, Printer.Windows 10 compatible.