Pre 2014 Blogs

Here is one way to model multiple pumps between the same downstream and upstream nodes using the pump curves and the Real Time Control Rules (RTC) in SWMM 5.  Here are the steps:

1.   Enter the data for three pumps in the browser by using the Add Pump Icon

2.   Enter three Pump Head/Flow Curves so that the 2^nd and 3^rd Pump Curves are the sum of the flows in the 1^st and 2^nd Pumps together and the sum of the flows in the 1^st, 2^nd and 3^rd respectively for the 2^nd and 3^rd Pump Curves

3.   Enter a RTC Rule in the Control Editor so that when the 1^st Pump is turned on – the 2^nd and 3^rd Pump is turned off

4.   Enter a RTC Rule in the Control Editor so that when the 2^nd  Pump is turned on – the 1^st  and 3^rd Pump is turned off

5.   Enter a RTC Rule in the Control Editor so that when the 3^rd  Pump is turned on – the 1^st and 2^nd Pump is turned off

Using these rules you can see that for the 1^st Pump turns on when the Node WetWell has a depth below 2 feet, the 2^nd Pump turns on when the Node is between a depth of 2 to 5 feet and the 3^rd Pump turns on when the Node Depth is above 5 feet.

RULE Pump1

IF Node WetWell Depth <= 2

THEN PUMP PUMP2 STATUS = OFF

AND PUMP PUMP3 STATUS = OFF

Priority 1

RULE Pump2

IF Node WetWell Depth > 2

AND Node WetWell Depth <= 5

THEN PUMP PUMP1 STATUS = OFF

AND PUMP PUMP3 STATUS = OFF

Priority 2

RULE Pump3

IF Node WetWell Depth > 5

THEN PUMP PUMP1 STATUS = OFF

AND PUMP PUMP2 STATUS = OFF

Priority 3