View Full Version : Switch Off Level pump

September 28, 2016, 02:12 AM

I have set the Switch Off Level of my pump at +0.0 m AD, but when I look at the graph of the water level of the upstream buffer, the water level never goes below +0.7 m AD.
I would expect that the minimal water level in the buffer would be about +0.0 m AD.
Did I do something wrong or is there a simple explanation?

Thanks, Karel-Jan

Patrick Moore
September 29, 2016, 10:25 AM

Could you confirm which of our software platforms you are using? Is this InfoWorks WS or InfoWater-H2ONET-H2OMAP Water related or one of our gravity flow platforms like InfoWorks ICM or InfoSWMM-InfoSewer?

Here are some general comments that often generally apply to all that might help troubleshoot.

1) Try shortening the reporting interval to a smaller value. Pump switching on and off often occurs between reported output intervals. Shortening results up to say 5 or 15 minute intervals can sometimes explain things as then you can see and verify the operation is occurring as requested that you cannot always see when you report output only at hour intervals which is fairly common. When you do this you can get a better sense of what is actually occurring when the control statement is triggered.
2) If the control is used is based off a tank level, it is best to not use a tank level associated with the minimum level or zero level on the tank to turn a pump on or the max level to turn a pump off. These levels can sometimes never be "reached" and can cause problems in controls. It is best to use on setpoints just above the min levels and just below the maximum levels to be safe. You use of +0.0 AD may impact the ability to turn the pump on. Try adjusting that slightly higher and see if it helps.

Patrick Moore

September 29, 2016, 11:41 PM

Thank you for your response!
I use InfoWorks ICM.
It indeed helps to shorten the time step of the simulation, it still doesn't reach +0.0 m AD, but I'am getting much closer.
So I assume the pump works correctly, but it is just difficult to see on the graph.


Patrick Moore
September 30, 2016, 08:06 AM

I am going to move this thread to our Wastewater thread as most of our InfoWorks ICM users are there and should better be able to advise you in your inquiry.

Thank you.

Patrick Moore