GE Hydran M2-X, Инструкция по эксплуатации

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Page 139
Hydran* M2-X Instruction Manual
MA-029 Rev. 1.0, 30-Jul-18
Frequency : Annually (minimum) or on alarm
The DGA is the reference method used to determine the exact level of dissolved
gases in oil. A DGA should be performed at least once a year.
To verify the readings of the Hydran M2-X using a DGA, proceed as follows:
1. Note the Hydran M2-X ’s gas level reading.
2. Take an oil s ample from the sensor’s sampling port (see Appendix J).
3. Send the sample to a qualified laboratory.
The DGA results include the concentrations, in parts per million (ppm), of the
following gases:
•
Hydrogen (H
2
)
•
Carbon monoxide (CO)
•
Acetylene (C
2
H
2
)
•
Ethylene (C
2
H
4
)
•
Methane (CH
4
)
•
Ethane (C
2
H
6
)
•
Carbon dioxide (CO
2
)
•
Nitrogen (N
2
)
•
Oxygen (O
2
)
The Hydran M2-X gives a composite reading of the first four gases in the above
list, in other words the gases generated by transformer incipient faults. This reading
can be compared to the DGA results using the following formula:
Hydran M2-X reading = 100 % [H
2
] + 15 % [CO] + 8 % [C
2
H
2
] + 1.5 % [C
2
H
4
]
A few examples are given in Table 9-2 below. The difference between the actual
and the calculated readings should fall within the technical specifications of the
Hydran M2-X.