Transformer Oil

Appearance

A representative sample of the oil shall be examined in a 100 mm thick layer at 27 ^oC

The Oil shall be clear and transparent and free from suspended matter or sediments

OK

Density g/cmq; at 29.5 ^o C

IS: 1448 (P-16) 1977

-

0.89

0.845

Kinematic Viscosity, cst at 27 ^oC at 40 ^oC

IS: 1448 (P-25) 1976

Under Consideration

27

13.85

Interfacil Tension, N/M at 27 ^oC

IS: 6104-1970

0.04

-

0.043

Flash Point, Pensky-Marten (Closed) ^oC

IS: 1448 (P-21) 1970

140

-

150

Pour Point, ^oC

IS: 1448 (P-10) 1970

-

(-6)

18

Neutralization valve
Total Acidity, mg. KOH/gm
Inorganic acidity/ alkalinty

IS: 1448 (P-2) 1967

-

0.03 Ni

0.006 Nil

Corrosive Sulphur Copper Strip, 19 Hrs at 140 ^oC

Annex. B

Non-corrosive

Non-corrosive

Electric Strength (Breakdown Voltage), KV (rms)

New unfiltered oil
After filteration

IS: 6792-1972

30

60

-

64

Dielectric Dissipation factor (tan Delta) at 90 ^oC

IS: 6262-1971

-

0.002

0.0007

Specific resistance (resistivity), ohm-cm
At 90 ^oC
AT 27 ^oC

IS: 6103-1971

35 x 1012
1500 x 1012

-

300 x 10¹²
295 x 10¹²

Oxidation Stability
Neutralization value, after oxidation for 164 Hrs at 100 oC mg KOH/ gm
Total sludge, 164 Hrs at 100 oC, wt %

Annex C

IS: 12177:1987

-

0.40

0.10

0.06

0.02

Accelerated agein test (open beaker Method with copper catalyst) 96 Hrs at 115 ^oC
Specific resistance (resistivity) ohm-cm at 27 ^oC
Specific resistance (resistivity) ohm-cm at 90^oC
Dielectric Dissipation factor (tan delta) at 90 ^oC
Total Acidity, mg KOH/gm
Total Sludge Valve % wt.

Method A
IS: 12177:1987
IS: 6103-1971
IS: 6103-1971
IS: 6262-1971
IS: 1448-(P-2) 1967
IS: 12172:1987

2.5 x 10¹²
0.2 x 101²

0.20

0.05

0.05

12-18 x 10¹²
3.14 x 10¹²
0.009

Nil

Nil

Presence of oxidation inhibitor

IS: 13631:1992

The oil shall not contain any antioxidant additives

N.D.

Water Content, ppm

IS: 13567: 192

50

16

SK Value %

Deleted

Deleted

4-8%

-