Unequal Run Times

Application

This anomaly type is applicable to two-pump wastewater pumping stations, in which the pumps are set to alternate regularly, with equal run time, at each cycle.

The anomaly type is disabled for device types for which, in general, the pumps do not alternate regularly.

Description

Users are notified of this anomaly if the run time of one pump exceeds that of the other pump in the station by more than 20% for three consecutive days.

Possible causes

• A difference in capacity between the pumps
• An issue with the configuration of the station:
  • One pump always starts at a higher level than the other pump does.
  • The stop level is set differently between the pumps.
  • The stop level is too low, which causes one pump to run at a snore state level.
  • The pumps do not alternate regularly.
• A fault in a pump or in the pump control
• An issue with the non-return valve of a pump

Related charts for evaluation

For instructions on where to find the related charts for examination, see
"Where do I find the anomaly charts for examination?" under Event FAQs > Anomalies.

Description of the chart Detail of pump utilization

The chart shows the following data:

• The running status of each pump in the station
• The water level, if available

The time period in the chart is one day with the maximum resolution:

• If the anomaly is active, the chart shows the previous day.
• If the anomaly has ceased, the chart shows the day that the anomaly started.

The chart allows the user to evaluate the following items:

• The issue that has caused the anomaly
• The current state of the station, if the anomaly is still active

Description of the chart Comparison between the pump utilization

The chart shows the daily utilization for each pump in the station. The time period in the chart is multiple days. The chart allows the user to evaluate the following items:

• The extent of the difference in utilization between the two pumps
• The frequency of the issue occurrence

Evaluation of charts, example 1

The charts show that pump 1 has lost capacity at the end of February:

• The chart Detail of pump utilization shows that the cycles of pump 1 are longer than the cycles of pump 2.
• The chart Comparison between pump utilization shows that the utilization of pump 1 has increased significantly at the end of February.

 

Evaluation of charts, example 2

The chart Detail of pump utilization shows that, since February 27, the trend of water level differs significantly from its regular pattern and that the pump cycle is very long. This behavior indicates that there is an issue in the pump control, rather than in the pump capacity.

The chart Comparison between pump utilization confirms the issue because the difference in the pump utilization swaps after a few days.

Disable the anomaly type

If the behavior that is identified as an anomaly is normal for a station, the anomaly type should be disabled. For more information, see "How do I enable or disable an anomaly type?" under Event FAQs > Anomalies.