36067144 transformer oil specifications

7/28/2019 36067144 Transformer Oil Specifications

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TRANSFORMER OIL

SPECIFICATIONS

BY

CENTRAL INSULATING OIL TESTING LABORATORY


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TRANSFORMER OIL SPECIFICATIONS

NEW OIL:

An unused mineral insulating oils intendedto use in transformers for insulation and

cooling purpose.

IS-335/1993 Specification for uninhibited

new insulating oils.

IS-12463/1988 Specification for inhibited

mineral insulating oils.


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IEC -60296/2003 Specification forunused mineral insulating oils for

transformers and switchgear. This

standard cover both uninhibited andinhibited oils.

ASTM D3487/2000- Standard

Specification for Mineral Insulating Oil

used in Electrical apparatus. This standard

also covers both uninhibited and inhibited

oils.


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Unused Mineral Insulating oils filled inNew transformers

IS 1866/2000 Code of Practice for

Electrical Maintenance and supervision ofMineral Insulating oil in Equipment.

(Refer Table.1 for limiting values of

various parameters)

IEC 60422/1998 Supervision and

maintenance guide for mineral insulating

oils in electrical equipment.


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In service Mineral Insulating oils:

IS 1866/2000 Code of Practice forElectrical Maintenance and supervision of

Mineral Insulating oil in Equipment.

(Refer Table.2 for limiting values ofvarious parameters)


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IS-335/1993

Appearance ------------ Density at 29.5C (Max)

Kinematic Viscosity (Max)

1) at 27C ------------------

2) at 40C ------------------ IFT at 27C (Min) ---------

Flash Point (Min) ---------

Pour Point (Max) ---------

Neutralization Value

1) total Acidity (Max) ----

2) Inorganic acidity ------

Corrosive Sulphur -------

Clear and transparent 0.89 g/cm2

27 cSt

Under consideration 0.04 N/m

140C

-6C

0.03 mg KOH/gm

Nil

Non-corrosive


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IS-335/1993

Electric Strength (BDV)1) New unfiltered Oil(Min)

2) After filteration (Min)

Dielectric dissipationfactor (tan )at 90C(max)

Specific resistance(Resistivity)

1) at 90C (Min)

2) at 27C (Min)

Oxidation Stability

1) Acidity (max)

2) total sludge (max)

30 KV (rms)

If the above value is notattained, the oil shall befiltered to 60 KV (rms)

0.002

35 x 1012 ohm-cm

1500 x 1012 ohm-cm

0.4 mg KOH/gm

0.1 % by weight


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IS-335/1993

Ageing characteristicsa) Resistivity (Min)

1) at 27C

2) at 90C

b) Tan at 90C (Max)c) Total acidity (Max)

d) Total sludge (Max)

Presence of Oxidation

inhibitor

Water content

SK value

2.5 x 1012 ohm-cm

0.2 x 1012 ohm-cm

0.20

0.05 mg KOH/gm

0.05 % by weight

The oil shall contain

natural anti oxidantadditives.

50 ppm

Under consideration


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IS-1866/2000-Recommended Limits of Unused Mineral Oil filled in New

Transformer

Property Highest voltage of Equipment (KV)170

Appearance Clear, Free from sediment andsuspended matter

Density at 29.5C (g/cm2),Max 0.89 0.89 0.89

Viscosity at 27C (cSt),Max 27 27 27

Flash Point (C),Min 140 140 140

Pour Point (C),Max -6 -6 -6

Total acidity(mgKOH/gm),Max 0.03 0.03 0.03

Water content (ppm), Max 20 15 10

IFT at 27C (mN/m),Min 35 35 35

Tan at 90C, Max 0.015 0.015 0.010

Resistivity at 90C(x10e12ohm-

cm),Min

6 6 6

BDV (K

V),Min 40 50 60


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IS-1866/2000-Violation Limits for in service oils

Property Highest voltage of Equipment (KV)

170

Appearance Clear and without visual contaminations

Water content (ppm), Max No Free water 40 20

BDV (KV),Min 30 40 50

Total acidity(mgKOH/gm),Max 0. 3 0. 3 0. 3

IFT at 27C (mN/m),Min 15 15 15

Resistivity at 27C(x10e12ohm-

cm),Min

1 1 1

Resistivity at 90C(x10e12ohm-cm),Min

0.1 0.1 0.1

Tan at 90C, Max 1.0 1.0 0.2

Flash Point (C),Min Maximum decrease of 15C from initial value

Sediment and sludge No sediment or precipitable sludge should be detected.Results below 0.02% by mass may be neglected.


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IS-1866/2000-Frequency of testing

Property Frequency of testing

Appearance In conjunction with other Quantitative tests

Water content After filling or refilling prior to energizing, then afterthree and 12 months, subsequently along with DGA

BDV After filling or refilling prior to energizing, then yearly

Total acidity Yearly

IFT After filling or refilling prior to energizing, then yearly

ResistivityAfter filling or refilling prior to energizing, then yearly

Tan After filling or refilling prior to energizing, then yearly

Flash Point Yearly

Sediment and sludge Yearly


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IS-1866/2000-Recommended Actions

Property Recommended Actions

Appearance As dictated by other tests

Water content Check Source of water and consider reconditioning

BDV Recondition the oil or alternatively, if moreeconomical or other tests dictate replace oil

Total acidity Replace or reclaim oil

IFT Replace or reclaim oil

Resistivity Replace or reclaim oil

Tan Replace or reclaim oil

Flash Point Replace the oil, equipment may require inspection

Sediment and sludge Where sediment is detected recondition the oil


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IS-1866/2000-Classification of oils in service.

Group 1:

This group contains oils that are insatisfactory condition for continued use.

The frequency can be followed as

described earlier.


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Group 2:

This group contains oils that requiresreconditioning for further service. (Low

BDV and High water content). The

frequency can be followed as described

earlier after reconditioning.


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Group 3:

This group contains oils in poor conditionthat it can restore satisfactory properties

only after reclaiming. Insulating oils this

group should be reclaimed or replaced

depending on economic considerations.


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Group 4:

This group contains oils, in such poor statethat it is technically advisable to dispose of

them.


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IEC -60296 General Specification

Functional Properties:Viscosity, Pour point, Water content, BDV,Density, Tan.

Stability Properties:Appearance, Acidity, IFT, corrosive Sulfur,Antioxident additive

Performance Properties:

Oxidation Stabillity, Sludge

HSE Properties:

Flash Point, PCB content, PCA content

36067144 transformer oil specifications

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