Transformers:
Oil analysis:
The tests included in the assessment are: Total Acid Number (high precision) and pH, Peroxide number,
Interphase tension, turbidity, dissolved oxidation products, moisture content, electrical breakdown voltage,
Additive contents eg antioxidant BHT and corrosive sulfur agent DBDS, Elemental composition eg sulfur,
chlorine and copper contents (+20 more elements)
Dissolved Gas analysis:
High Precision DGA has the power to determine a coming fault up to and more than 5 years in advance
(Extraction based DGA) while the normally performed screening DGA (so called Head-Space DGA) has the
power of detecting only larger fault ie faults which will occur relatively soon after the DGA is performed
High precision DGA thus provides the tools for determining the fault and in good time plan how to remove the
fault. This type of DGA is of maximum interest when it comes to factory testing and to guarantee period
condition assessment as slowly appearing faults are not at all determined by HS (screening DGA).
Thermal faults are always slowly appearing and may be due to design errors; they dont show until operating at
full load for a long period.
High precision DGA must include density and is not only gas extraction but therefore also oil type determining.
The report provides information on maintenance needs for the object and about possible faults or fault
indications.
Trafodiagnosis:
Based on oil + gas analysis.
Conclusions in the report is based on assessing DGA and oil data simultaneously to determine if discrepancies
exist. This leads to a much more exact condition assessment both with regards to fault assessment and
maintenance requirements.
Condition Assessment Report:
Gas + full set of oil analyses including some not revealed methods.
Overall, the report gives a very good picture of the transformer current state.
Remaining lifetime Assessment:
Same as the state report but also including calculation of the remaining life based on operational data provided
by the owner of the object
Lubrication, hydraulics and gear boxes:
Lube oil composition varies strongly with respect to base oil and additive content and oil
companies claim unique knowledge about these matters. However, todays analytical lab
instrumentation does not allow any secrets; every oil can be content determined down to
its lowest content additive. These investigations are however not very often justified
because of the costs and time involved. It must be understood by the oil user that every
oil company benefits from manufacturing “several-purpose” lubes and therefore the oil
user very seldom uses the lubricant which i optimum for his application.
Diagnose 1:
Lube oil analysis is oriented to dirt accumulation, wear and antioxidant determination for the oil.
Gravimetric cleanliness by ICP filter, ICP, Moisture, Total Acid Number, pH.
This test category referred to sliding (plain) bearing system. Plain bearings are characterized by large
tolerances, and hence a large dirt accumulation can be accepted in some cases. However, the more modern the
machine the less acceptance for this type of contamination.
As long turbine shaft angular velocity is close to the design data the lubricant film thickness is always sufficient
and the oil viscosity provides lubrication. Oil metal adhesion influence some times and oil polarity is in such
cases of interest.
Diagnose 2:
Gravimetric cleanliness by ICP filter, ICP, moisture, Total Acid Number, pH
An expanded version of diagnose 1, where we also perform an elemental analysis of the oil.
This is a smaller version of the systems condition package and thus provides only basic data.
System conditon:
Gravimetric cleanliness by ICP filter, ICP, moisture, Total Acid Number, pH, antioxidants, olefin bonds and FT-IR.
This category oils also refer to plain bearing systems with the difference being that they are common with the
regulating system whose susceptibility to dirt accumulation is quite different from plain bearing system.
Today’s trend towards higher regulating pressure also means that the system tolerance to dirt accumulationd
decrease and that erroneous oil formulations more often will be the problem for the system.
Large Gear box:
Gravimetric cleanliness by ICP filter, ICP, moisture, Total Acid Number, pH, density, refractive index and additive
content and viscosity by Brookfield.
Reports the wear of gears, and gives details about the oil content of the protective additive to the machine and
oil.
Viscosity is basic for lubrication of gears.
Small Gear box:
Gravimetric cleanliness by ICP filter, ICP, density, refractive index. Cheap Variant of large package.