Property

Test method

Limits

Transformer oil

Low temperature
Switchgear oil

1-Function

Viscosity at 40℃

ISO 3104

Max. 12 mm²/s

Max.35 mm²/s

Viscosity at –30℃a

ISO 3104

Max. 1 800 mm²/s

--

Viscosity at –40℃b

IEC 61868

--

Max. 400 mm²/s

Pour Point a

ISO 3016

Max. –40℃

Max.–60 ℃

Water content

IEC 60814

Max. 30 mg/kg c / 40 mg/kg d

Breakdown voltage

IEC 60156

Min. 30 kV/70 kVe

Density at 20℃

ISO 3675 or ISO 12185

Max, 0,895 g/ml

DDF at 90℃

IEC 60247 or IEC 61620

Max. 0,005

2-Refining/stability

Appearance

--

Clear, free from sediment and suspended matter

Acidity

IEC 62021-1

Max.0,01 mg KOH/g

Interfacial tension

ISO 6295

No general requirement f

Total sulfur content

BS 2000 Part 373 or ISO 14596

NO general requirement f

Corrosive sulfur

DIN 51353

Not corrosive

Antioxidant additive

IEC 60666

(U) uninhibited oil: not detectable
(T) trace inhibited oil: max. 0,08%
(I) inhibited oils:0,08-0,40%

2-Furfural content

IEC 61198

Max. 0,1 mg/kg

3-Performance

Oxidation stability ¹

IEC 61125(method C)
Test duration:
(U)Uninhibited oil:164 h
(T) Trace inhibited oil:332 h
(I) Inhibited oil:500 h

-Total acidity

Max. 1,2 mg KOH/g ¹

-Sludge

Max. 0,8 % ¹

DDF at 90℃

IEC 60247

Max.0,500 ¹

Gassing

IEC 60628,A

NO general requirement

4-Health, safety and environment (HSE)

Flash point

ISO 2719

Min. 135℃

Min. 100℃

PCA content

BS 2000 Part 346

max. 3%

PCB content

IEC 61619

Not detectable

a  This is the standard LCSET for an transformer oil (see 5.1) and can be modified  depending on the
climatic
b  Standard LCSET for low temperature switch gear oil.
c  For bulk supply.
d  For delivery in drums and IBC.
e  After laboratory  treatment (see 6.4).
f  Where it is used as a general requirement, a limit of minimum 40 mN/m is recommended.