GE Hydran 201i - High and High-High Alarms Triggering

MA-033 Rev. 14.0, 12-Nov-18
Hydran* 201i Instruction Manual
Page 166
Initial
After 8 hours
After 24 hours
After 48 hours
0ppm/24 hr
+4ppm/24 hr
+9ppm/24 hr
+10ppm/24 hr
Table 11-5: Evolution of the Hourly Trend
Example 2: The gas level starts to increase at a rate of 50 ppm/30 days. The daily
trend period is set to 30 days.
Initial
After 10 days
After 30 days
After 60 days
0ppm/30 d
+20ppm/30 d
+45ppm/30 d
+50ppm/30 d
Table 11-6: Evolution of the Daily Trend
Note the following points:
• If the Hydran 201Ti undergoes a power failure that lasts less than 1/6 of the
trend period, the corresponding trend reading remains constant until the
H201Ti is powered up again.
• If the power failure lasts more than 1/6 of the trend period, the corresponding
trend reading is reset to zero.
• If the user changes the hourly or daily trend period, the corresponding trend
reading is reset to 0.0 ppm/period.
11.4.4 High and High-High Alarms Triggering
If the High alarm relay is set to the Normal or Latch mode, the High alarm is
triggered (the High alarm relay is energized) when one of the alarm conditions exceeds
the corresponding High alarm set point during a period of time exceeding its alarm
delay.
The same way, if the High-High alarm relay is set to the Normal or Latch mode, the
High-High alarm is triggered (the High-High alarm relay is energized) when one of the
alarm conditions exceeds the corresponding High-High alarm set-point during a period
of time exceeding its alarm delay.
Each alarm (High and High-High) can be triggered by one or several of the following
conditions (for details, see Section 11.1.1):
• Gas level (GasLevel submenu).
• Hourly trend (HourlyTrend submenu).
• Daily trend (DailyTrend submenu)
Each alarm condition has an adjustable alarm delay that is common to all levels
(High, High-High, Low and Low-Low) of this condition.