GE Hydran 201i, Instruction Manual

Page: 240 / 300

Chapter 13 • Maintenance
13-4 Rev. 6, March 2011 Part 17997
• Methane (CH
4
)
• Ethane (C
2
H
6
)
• Carbon dioxide (CO
2
)
• Nitrogen (N
2
)
• Oxygen (O
2
)
The Hydran 201 i System 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:
H201T i reading = 100 % [H
2
] + 18 % [CO] + 8 % [C
2
H
2
] + 1.5 % [C
2
H
4
]
A few examples are given in Table 13-2 on page 13-4. The difference between the actual
and the calculated readings should fall within the technical specifications of the
Hydran 201
i System.
Table 13-2 - Examples of Gas Reading Comparisons Between a DGA and a Hydran 201T
i
13.3 HYDRAN 201T
I
VERIFICATION
Frequency : Annually or on fail alarm
Note: Alarms are triggered during this verification procedure. Please warn the appropriate
personnel.
Dissolved Gas Analysis (DGA) (ppm)
H201T
i
Reading
(ppm)
Hydrogen
(H
2
)
Carbon Monoxide
(CO)
Acetylene
(C
2
H
2
)
Ethylene
(C
2
H
4
)
100 0 0 0 100
100 1000 0 0 280
100 100 0 0 118
100 100 50 0 122
100 100 50 200 125
CAUTION
WARNING
Read the precautions listed in Section 5.1 on page 5-1 before
handling the Hydran 201 sensor.