Casestudie Breakdown prediction Contell PILOT - Transumo

Table 6-4: Classification of Alarms
Selected Offset time (Minutes) Number of Alarms Caused by Door Openings
1 139/158
2 155/158
3 156/158
4 157/158
10 158/158
To classify these user made alarms, the suggested classes from section 5.10.3 are
taken. Moreover the suggested criteria are used to determine the current condition.
Table 6-5 contains the corresponding results of data analysis of the selected sample
dataset. Due to the historical behavior, a green alarm will currently be raised in case
of a door opening that takes at least 19 seconds because 50 percent took less time.
Moreover, a temperature of 6.9°C or higher and a temperature exceeding of 7
minutes or more would have the same effect. But as this data is calculated
dynamically, these results only mirror a snapshot.
Table 6-5: Results of Classification According to Single Criterions
Duration of Door
Openings
Maximum Temperature
During an Alarm
Maximum Duration
of an Alarm
Green Alarm ≥ 19 Seconds ≥ 6,9°C ≥ 7 Minutes
Yellow Alarm ≥ 38 Seconds ≥ 7,8 °C ≥ 12 Minutes
Red Alarm ≥ 84 Seconds ≥ 9,8 °C ≥ 27 Minutes
Occurred Red
Alarms
39 8
42
9
Beside current limits for the single alarm classes, the last row of Table 6-5 is of
special interest. It contains the number of red alarms that would have been raised
during the whole monitoring time. This quantity of 42 red alarms is significantly
different to 158, so that more than 60% of all occurred alarms could be classified as
not that critical. But if this classification method is applied to very critical devices,
additional conditions are needed. If, for instance, the temperature level may not
exceed for more than 15 minutes, the red alarm should go off earlier.
100