MA-025
–
DGA 900 Operator Guide
–
Rev 2.0
12-Apr-19
Page 90 of 92
Table E-3: ROC alarms (for ROC in ml/day)
ml/day
Hydrogen
(H
2
)
Methane
(CH
4
)
Acetylene
(C
2
H
2
)
Ethylene
(C
2
H
4
)
Ethane
(C
2
H
6
)
Carbon
monoxide
(CO)
Carbon
dioxide
(CO
2
)
TDCG
Caution
2.5
1
0.05
1
1
25
-
5
Alarm
5
2
0.1
2
2
50
-
10
E.5
Measurement Intervals
If the customer does not have a policy for measurement intervals, use the following
measurement intervals (in hours):
Table E-4: Measurement intervals
In Hours
DGA 900
Normal
8
Caution
4
Alarm
1
E.6
Other Settings / Alarm Setups
In TransConnect, remember to map Caution and Alarm values to Caution/Alarm indicators,
Caution/Alarm modes, any wired relays and SMS messaging as required.
E.7
Important Notes
All alarm and measurement interval settings must be approved and signed off by the
customer.
After oil treatment (degassing, regeneration, drying, mixing, etc.), the alarm settings
should be reviewed and changed if necessary.
E.8
Example (Main Tank)
The maximum measured value of ethylene is 48 ppm.
This is close to the limit in Table E-1, so the Caution should be set to 120% of the value and
Alarm to 150% of the value.
Caution
58 ppm
Alarm
72 ppm
The rate of change alarms should also be set.
Caution
0.4 ppm/day
Alarm
1.0 ppm/day
