10.5.2 Fault Triggers; Gas Fault Triggers - GE Hydran 201 i Instruction Manual

10.5.2 Fault Triggers

Fault triggers are fail alarm conditions that can produce two actions:
• Display of a message on the screen. The alarm message is displayed only if the corre-
sponding alarm set point is adjusted to a value; if not, it is set to OFF. This setting is
performed in the corresponding submenu.
• Trigger of the fail alarm relay. Whether the relay is triggered when an alarm condition is
detected is determined in the SysOK Relay;FaultTrig. submenu.
Note: The alarm set point adjustment has priority over the relay triggering. In other words,
the relay is not triggered if the alarm set point is adjusted to OFF.
Almost all these alarm conditions have an alarm set point and an alarm delay (both can be
adjusted). The fail alarm, for these conditions, is therefore triggered the same way than the
gas High and High-High alarms:
• Low and Low-Low alarms: The fail alarm is triggered when one of the alarm conditions
is below the corresponding alarm set point during a period of time exceeding its alarm
delay.
• High and High-High alarms: The fail alarm is triggered when one of the alarm conditions
exceeds the corresponding alarm set point during a period of time exceeding its alarm
delay.
10.5.2.1

Gas Fault Triggers

The conditions shown in Table 10-7 on page 10-16, although being Low and Low-Low gas
alarms, are classified as fail alarms because they indicate a problem of gas detection rather
than one of gas production in the transformer. A gas Low alarm, for example, is triggered
if the valve on which is mounted the Hydran 201Ti is closed.
The parameters pertaining to these alarm conditions are set in the H201Ti's Gas and
SysOK Relay;FaultTrig. submenus (for explanations, see Chapter 4).
Part 17997 Rev. 6, March 2011
Fail Alarm
10-15