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WorksheetsPowerGen Rising Star 3
Total questions: 50
Worksheet time: 25mins
Mineral oil is used in transformers primarily due to ?
It protecs the solid insulation
It dispese heat
It is cost effective
All of the above
Which gas generated by transformer fault is not a combustible gas
Carbon dioxide
Methane
Hydrogen
Ethylene
The end of reliable life of solid insulation in a transformer is measured by the ?
Thickness
Density
Weight
Degree of Polymerization
Which of the following will not accelerated the aging of mineral oil dielectric fluid?
Heat
Inhibitor
Oxygen
Water
Neutralization number and interfacial tension are both good direct measures of?
Moisture in oil
Disslove gasses in oil
Oxidation (aging) of the oil
Furanic compounds in the oil
At normal design temperature (110 deg C or less in a normally operated modern transformer) small but measurable concentrations of these following gases will be formed
Ethane and Methane
Acetylene and Ethylene
Carbon monoxide and carbon dioxide
Hydrogen and methane
Analysis of furanic compounds is used to evaluate the condition of the?
Liquid insulation
Solid insulation
Core steel
Transformer bushings
To perform a quantitative analysis of dissolved gas concentrations which method isn't used?
Rogers ratio
Duval triangle
polarization ratio
Doernenberg ratio
What does NOT cause cellulose molecules (the solid insulation in your trasformer) to depolymerize/weaken?
Heat
Oxygen
Water
Higher voltages
Where does the moisture in a transformer come from?
Leaks
Oil and cellulose breakdown
Inadequate drying at factory
All of the above
......is method for colour testing for oil
ASTM D6304
ASTM D1500
ASTM D130
ASTM D974
What kind of solvent used for diluting the sample in color analysis ?
Heptane
Kerosene
Hexane
Acetone
What kind of chemical used for sediment and sludge analysis based on ASTM D1698
Heptane
Hexane
Pentane
Acetone
To which standard method reffered to, to determine the level of corrosivity based on ASTM D1275
ASTM D445
ASTM D130
ASTM D974
ASTM D1298
Gap between electrode based on IEC 60156..
2.0 mm
2.5 mm
1.0 mm
1.5 mm
Also known as natural oxidation ihibitor
Copper
Iron
Sulfur
Silver
Source of sulfur in a transformer system
Gasket material
Glues
Oil
All of the above
Metal deactivators to refard or delay attack by corrosive sulfur
di butyl para cresol
Benzotriazole
di butyl phenol
di butyl di sulfide
What problem does water cause?
Increase Interfacial tension
Decrease acid number
Decrease furanic compounds
Decrease dielectric strength
Should not be analyzed more than 7 days..
Interfacial tension
Acid Number
DDF
Moisture content
Tendency of the liquid to tighten so that the surface is covered by an elastic layern is the definition of
Surface tension
Interfacial tension
Breakdown voltage
Dissipation factor
Tolerance for the calibration of 500 mg Du Nuoy Ring in interfacial tension analysis
490-510 mg
480-520 mg
500-510 mg
500-520 mg
The sample volume range for conducting a BDV test
300-600 ml
350-600 ml
400-600 ml
450-600 ml
Which ASTM method correlate to corrosive sulfur level of tarnish
ASTM D445
ASTM D971
ASTM D130
ASTM D664
Parts of transformer
Core steel
Winding
Conductor
All of the above
Standard method use for furan-moisture-DGA
IEC 61198-IEC 60814-IEC 60516
IEC 60841-IEC 60516-IEC 61198
IEC 61189-IEC 60814-IEC 60156
IEC 61198-IEC 60814-IEC 60156
Categories equipment based on IEC 60422, except..
A
O
I
D
Neutralization method, except..
ASTM D974
ASTM D664
IEC 62021
IEC 60296
Recommended action limit for sediment and sludge..
0.01%
0.02%
0.03%
0.04%
Dilution ratio for oil and kerosene for color parameter in oil insulating analysis
20 : 80
85 : 15
80 : 20
15 : 85
Principal method use in sediment and sludge analysis
Potentiometric
Gravimetry
Chromatoghraphy
Titrimetry
Typically, the only moving parts in an energized transformer are
Secondary switchgear
Load tap changer
No load tap changer
Voltage arrestor
which one of the furan compounds could form caused by lightning
2H2F
2FOL
2ACF
2FAL
The most abundant type of furan compound
2FOL
2FAL
2ACF
5HMF
Refer to ASTM used, how to report the sediment and sludge if the result below 1%..
Report in 1 digits
Report in 2 digits
Report in 3 digits
Report in 4 digits
Based on IEC 60296 insulating oil were categorized as inhibited, if the inhibitor was..
More than 1%
1% - 3.5%
0.08-0.4%
less than 0.08%
Sediment and sludge in service aged insulating oil , primarily for oils of comparatively has viscosity of..(40 deg C)
5.3 to 13.0
4.5 to 9.0
5.0 to 11.0
11.0 to 12.0
Mobile phase in chromatography used for furan analysis based on IEC method
Water : Acetonitrile
Ethanol : Water
Water : Methanol
Ethanol : Acetonitrile
Type of thermal fault in a transformer
Arcing
Corona
Hot Spot
Sparking
Expected life of furanic compounds besides FAL, is
1 to 3 months
3 to 5 months
2 to 4 months
3 to 4 months
Total furan maximum concentration in normal aging condition based on SDMyers
20 ppb
50 ppb
100 ppb
150 ppb
What does the tangen delta describe ?
Chemical deterioration due to weather, temperature and overheating
Moisture content, effect of oil and etc
Various types of leakage and ionization
All of the above
Loss factor was analyzed at..degC based on IEC
40
70
90
120
One of the principal causes of gas formation within an operating transformer
Moisture
Operator
Electrical disturbances
Location of the transformer
Detector used in DGA analysis
ECD and FID
FID and TCD
FPD and TCD
TCD and ECD
Resting time for sample having viscosity more than 15 cSt before the first application of the voltage, based on the latest BDV method is...
5 minutes
5 to 10 minutes
15 to 30 minutes
30 to 40 minutes
syringe used in moisture content is in accordance to ?
ASTM D6304
ISO 595
IEC 60814
ASTM D93
Acceptance mean of value range in the latest IEC 60156 is..
2.0% - 95%
2.5% - 97.5%
2% - 97%
2.5% - 96%
Before used, Du Noy Ring should be barely glow orange and heated for not more than ?..
2 s
3 s
4 s
5 s
PowerGen Division parameters which already gain its accreditation status, Except..
Furan
Color
DGA
Density
