Unequal Number of Starts

Application

This anomaly type is applicable to two-pump wastewater pumping stations, in which the pumps are set to alternate regularly 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 number of starts of one pump exceeds that of the other pump in the station by more than 20% for a few consecutive days.

Possible causes

• One pump repeatedly fails to lower the water level and thus relies on the other pump to complete the cycle
• One pump repeatedly starts because of a fault in the pump, a fault in the pump control, or incorrect station configuration

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 Number of starts of the pumps

The chart shows the daily number of starts 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 number of starts between the two pumps
• The frequency of the issue occurrence

Evaluation of charts, example 1

The chart Detail of pump utilization shows that pump 2 frequently relies on pump 1 to complete the cycle.

The chart Number of starts of the pumps thus shows that the number of starts of pump 1 is more than that of pump 2.

The charts show that the issue has occurred regularly in the past month.

Evaluation of charts, example 2

The chart Detail of pump utilization shows an irregular trend of the measured water level with unrealistic spikes. The chart also shows frequent, very short pump cycles that do not lower the water level. This behavior indicates that there is an issue in the control of the pumps.

The chart Number of starts of the pumps shows that the issue causes a high number of starts for both the pumps, particularly for pump 2.

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.