TRANSFORMER OIL classifications and specifications

Transforemr oil

2. Iron Core
Magnetic
lines
Devic
e
Secondary
coil
Primary coil
AC
Suppl
y

3. A transformer is a static device which is used to step
up or step down voltages at constant frequency
Itconsistsoftwocoils,thatareelectricallyisolatedbut
magneticallylinked
Theprimarycoilisconnectedtothepowersourceand
thesecondarycoilisconnectedtotheload
Voltageissteppeduporsteppeddownproportional
toturnsratio
Theturn’sratioistheratiobetweenthenumberof
turnsonthesecondary(Ns)tothenumberofturnson
theprimary(Np).
Working principle

5. Transformer classification
Based on construction
Core type
Shell type
Berry type
Based on application
Power transformer
Distribution transformer
Based on cooling
Oil filled self cooled
Oil fill water cooled
Air blast type

6. Transformers types based on construction

7. Transformers types based on application

8. Based on number of turns in the primary and secondary windings and the
induced emf.
Step-up transformer
Step down transformer
Step up and Step down Transformer

9. Power Transformer9

10. Distribution Transformer
10

11. Transformer OEMS11
1.ABB India
Corporate Office –Bangalore, Karnataka | Establishment –1889
2.Siemens India
Corporate Office –Mumbai, India | Establishment –1867
3.Alstom T&D India
Corporate Office –Noida, India | Establishment –1911
4.Transformers & RectifiersIndiaLtd
Corporate Office –Gujarat, India | Establishment –1994
5.KirloskarElectric CompanyLimited
CorporateOffice –Bangalore, Karnataka | Establishment –1946
6.Gujarat Transformers Pvt. Ltd
Corporate Office –Gujarat, India | Establishment –1974

12. Transformer Insulating system
To provide dielectric strength of the transformer
insulation system.
To provide efficient cooling.
To protect the transformer core and coil assembly
from chemical attack.
To prevent the build up of sludge in the transformer
To quench the arc produced while operation

13. Transformer oil classifications
NAPTHANIC OIL
PARAFFINIC OIL
SILICON OIL
Transformer Oil
Mineral Oil
(petroleum product )
Synthetic Oil
(Chemical Product)

14. Oxidation Inhibitor in mineral oil
Mineralinsulatingoilundergooxidativedegradationprocessinthepresenceofoxygento
formacid&sludge.Topreventtheseprocess,oxidationinhibitorisusedforinterrupting
processofoxidationandtherebyminimizeoildeteriorationandextendtheoperatinglife
ofthetransformertheoil.
Dependingonthepresenceofoxidationinhibitor,mineralinsulatingoiliscategorizedas–
1.Uninhibitedoil2.Inhibitedoil
1.Uninhibitedoil
Newinsulatingoilasnormallyrefinedcontainssmallamountsofcertainchemical
compoundsthatactasoxidationinhibitors.
2.Inhibitedoil
Toincreasetheoxygeninhibitorbeyonditsnaturallimit,oxygeninhibitorisaddedintheoil

15. TRANSFORMER OIL SPECIFICATIONS
NEW OIL:
An unused mineral insulating oils intended to use in transformers for
insulation and cooling purpose.
IS-335/2018 TYPE I –Specification for Naphthenic new insulating oils.
IS-335/2018 TYPE II –Specification for Paraffinic new insulating oils.
IEC -60296/2003 –Specification for unused mineral insulating oils for
transformers and switchgear. This standard cover both uninhibited and
inhibited oils.
ASTM –D3487/2000-Standard Specification for Mineral Insulating Oil
used in Electrical apparatus. This standard also covers both
uninhibited and inhibited oils.

16. HP TRANSFORMER OIL16

17. HP TRANSFORMER OIL SPECIFICATIONS
IS:335-2018 TYPE II UNINHIBITED (New Oil)
•Appearance ------------
•Density at 29.5˚C (Max)
•Kinematic Viscosity (Max)
1) at 0˚C (Max)---------
2) at 40˚C (Max)-----------
•IFT at 27˚C (Min) ---------
•Flash Point (Min) ---------
•Pour Point (Max) ---------
•Corrosive Sulphur -------
•PCA Content % (Max)
•PCB Content, mg/kg
•Clear and transparent
•0.89 g/cm
2
•1800 cSt
•15 cSt
•0.04 N/m (old, NA)
•135˚C
•-10˚C
•Non-corrosive
•3
•Non Detectable (<2)

18. TRANSFORMER OIL SPECIFICATIONS
IS:335-2018 TYPE II UNINHIBITED (New Oil)
•Electric Strength (BDV)
1) New unfiltered Oil(Min)
2) After filtration (Min)
•Dielectric dissipation factor
(tan δ)at 90˚C(max)
•Oxidation Stability
1) Total Acidity (max)
2) Sludge (max)
•DBDS, mg/kg
•Metal Passivator additive
•2 Furfurals & related
compound, mg/kg
•30 KV (rms)
•If the above value is not
attained, the oil shall be
filtered to 60 KV (rms)
•0.005
•1.2 mg KOH/gm
•0.8 % by weight
•Non detectable (<5)
•Non detectable (<5)
•Non detectable (<0.05)

19. PHYSICAL PROPERTIES OF OIL
Physical Properties Effects
Appearance
DecreasestheElectricalstrength,IFTvalue
etc.,
Density
Sincedensityisinverselyproportionalto
temperature,heatdissipationcapacityofthe
oildecreaseswiththedecreaseoftemperature
Kinematic Viscosity
Heat removal capacityfrom windings
increases with Low viscosity at low
temperature and prevent localized overheating.
Interfacial Tension
Oil with lower IFT reduces the cooling effect
due to presence of sludge & oil decay product

20. PHYSICAL PROPERTIES OF OIL
20
Physical
Properties
Effects
Flash point
Lowvaluetothespecifiedvalue–Risk
offireintransformer
Pour point
Lowvaluetothespecifiedvalue–
transformeroilstopflowing.
Sludge&
Sediments
Reducestheelectricstrengthandhinder
heattransfer.

21. CHEMICAL PROPERTIES OF OIL
Chemical
Properties
Causes Effects
Neutralizatio
n Number
or Acidity
Oxidation of
insulating oil due
to aging
Corrosion of various parts of transformer,
Lower the electric strength and causes
Insulation degradation
Oxidation
Stability Moisture
Metal corrosion which minimizes the life
of the transformer
Moisture
By breathing
action,
Chemical reaction
Decreases electric strength (BDV)
Electric dissipation factor (Tan Delta)
Resistivity
Dissolved
Gases
Thermal
degradation
Arcing,
Partial discharge
H
2= Partial discharge
H
2,CH
4 = Low energy discharge
CH
4= Low temp hot spot
H
2, C
2H
2= Arcing
C
2H
4= High temp

22. ELECTRICAL PROPERTIES OF OIL
Electrical
Properties
Definition Causes Effects
Dielectric
Strength
Itistheminimumvoltagethatoilcan
withstandduetoitsdielectricstrength
Solidimpurities
Watercontent,Fiber
Conductiveparticles
Higherthevalue,Higher
thepurity
Resistivity
Theresistivityofaliquidisameasureof
itselectricalinsulatingpropertiesunder
prescribedconditions.Highresistively
reflectslowcontentoffreeionsandion-
formingparticlesandnormallyindicatesa
lowcountratioofconductive
contaminants.
Moisture,Acidity
Solidcontamination
Higherthevalue,better
theconditionoftheoil
Dielectric
Dissipation
Factor / Tan
Delta PF = Cos φ = Cos ((90-∂) = Sin ∂ = Tan ∂
Heatdissipationintheinsulatorduetoleakage
Current=OAxOBTan∂(Watt)
Since heat dissipation in the insulator increases
With increase of PF / Cos φ / Tan ∂ -this factor is
known as dielectric dissipation factor and should
be
as low as possible
Solublevarnishes,resins,
Moisture
Increased value causes in
increase in temperature,
increase in corrosion
(Applied voltage V)O
Φ = (90-∂)
∂
A
B
C
Capacitive current
Actual current

23. Performance Reports23

24. Performance Reports24

25. Major supplies25

26. Storage and Handling Transformer Oils26
•Contamination of any kind is highly detrimental to the quality
and performance of transformer oil
•Storage tanks are normally made of mild steel or stainless steel.
•An oil resistant Epoxy coating is necessary on the walls of the
tank.
•Water content greatly affects the insulation properties. A silica
gel breather is can be used in humid areas.
•It is vital to keep the tank(s) completely separate, dedicated for
use with transformer oil. This applies of course to all piping and
lines that are used to transport oil to loading stations.

27. THANK YOU

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