Alarm Interface; Gas And Moisture Alarm Conditions - GE Hydran M2-X Instruction Manual

6.1.4 Alarm Interface

The alarm interface between the Hydran M2-X and the user can take different
forms. When an alarm is triggered, the following actions are generated:
1. An alarm message flashes on the Hydran M2-X's display. For the list of all
alarm messages that can be displayed by the Hydran M2-X, see Appendix I.
For details on the display of alarm messages, see Section 3.1.2.1.
2. The state of the corresponding alarm relay changes. The classic interface
method consists in linking the relays' alarm contacts of the Hydran M2-X to
an alarm panel (or any other SCADA system) located in such a way that an
alarm being triggered would immediately warn the operator. For details, see
Section 7.1.2.
3. A call can be made to the host computer via modem. See Chapter 5.
4. During an alarm due to system fault conditions, the optional analog output of
the Hydran M2-X drops to zero, and the NO fail alarm contact opens.
5. A message is recorded in the Events history file. Alarm messages are thus
stored in memory. The Events file can contain up to 500 messages. Each
message comes with a set of relevant parameters (gas and moisture levels,
trends, etc.) and is identified with the recording date and time. For details, see
Section 3.4.2.

6.2 Gas and Moisture Alarm Conditions

As listed in Table 6-1, there are a total of six gas alarm conditions (High and High-
High for level, hourly trend and daily trend) and a total of eight moisture alarm
conditions (High and High-High for moisture level, moisture average, relative
humidity and relative humidity average).
Note: Each analog input could also generate four alarm conditions: Low-Low, Low,
High and High-High.
For more information on the interpretation of gases in oil, refer to the following
guides:
• IEEE* Standard C57.104-1991, "IEEE Guide for the Interpretation of Gases
Generated in Oil-Immersed Transformers"
• IEC 60599-1999, "Mineral Oil-Impregnated Electrical Equipment in Service
– Guide to the Interpretation of Dissolved and Free Gases Analysis"
Page 108
Hydran* M2-X Instruction Manual
MA-029 Rev. 1.0, 30-Jul-18