I'm trying to run a 24-hour EPS in WaterCAD (starting at 12 AM) for a system with a booster pump and four hydropneumatic tanks. The initial condition is to have the booster pump turned off and the hydropneumatic tanks fully pressurized. I've set the controls so that the booster pump turns on when the hydraulic grades in the tanks drop to a certain level and shuts off when the hydraulic grades within the tanks rise to a certain level and when the demands in the system are below a certain level.
Whenever I run an EPS, the results show that the booster pump never turns on, and I get several user notifications saying "Hydropneumatic Tank HT-1/2/3/4 is empty." The same thing happens when I use the tanks' internal pressure as a basis for the booster pump controls.
Do you know what the problem might be?