GE Hydran M2-X Instruction Manual page 195

Hydran* M2-X Instruction Manual
The solubility of water in the oil depends on the nature of the oil (composition,
oxidation, etc.) and its temperature. For typical naphthalenic oils, the following
equation is given1 to calculate the PPMs:
where T is the measurement temperature in °C. By combining Equations 1 and 2
and by adding an offset of 2.4 ppm (typical value of bonded water for new oil), we
have:
This is the equation used by the Hydran M2-X to convert the RS into PPM, and the
resulting PPM value can be read on the display.
It is important to note that the value displayed by the Hydran M2-X is accurate
only for the new Voltesso 35 oil
own Equation 3 based on the nature of the specific transformer oil, in order to ensure
the accuracy of the computed PPM values. Otherwise, caution should be exercised
when comparing the displayed PPM value with a laboratory's Karl Fischer result.
As an example, Table K - 1
show the water solubility (or often called saturation) curves of various oils as a
function of the oil composition and temperature.
The user should keep in mind that in practice, the independent measurements of
relative saturation and PPM are necessary in order to obtain complete information
on the water content in the oil, and both measurements are complementary.
Esso Petroleum Product Data Sheet on Voltesso 35
1
V. Sokolov, P. Griffin and B. Vavin, "Moisture Equilibrium and Moisture Migration Within Transformer Insulation Systems," Cigre
2
Report WG12.18
S.P. Mehta and T.M. Golner, "Moisture Removal on Energized Power Transformers"
3
MA-029 Rev. 1.0, 30-Jul-18
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1
. The user has the responsibility to determine his
2 on the next page and Figure K - 1
+17,749
(Equation 2)
+17,749
+2.4 (Equation 3)
3 on the next page
Page 195