Hello,

I need to model a pump station. The pump station has 2 pumps: one duty and one standby

· The duty pump is switched on when the wastewater level in the wet well is greater than 3.75 AHD
The minimum wastewater level in the wet well is 2.75 AHD, and therefore when the level drops to 2.75 AHD the pumps are switched off.

· The standby pump starts working at 4.1 AHD and it stops working at 2.75 AHD

However, the pump station should be able to work if the wastewater level is rising in the wet well.


This is the RTC Group which I have written for this pump station:

For the duty one:

Unless subsequent rules are true, if the height above datum at node Wet Well is greater than or equal to 3.750m AD then Duty will be switched on
If the height above datum at node Wet Well is less than 2.750m AD then Duty will be switched off

For the standby one:

Unless subsequent rules are true, if the height above datum at node Wet Well is greater than or equal to 4.100m AD then Standby will be switched on.
If the height above datum at node Wet Well is less than 2.750m AD then Standby will be switched off

I do not know why when the inflow into the pump station is high the model cannot be solved.



Thank you very much.