Problem

After computing a pump shutdown or start-up in HAMMER, it doesn't look like the operating rule is being followed.

Solution

This could be occurring because of the value entered for the property "Time (For Valve to Operate)". It is possible to model the time from the start of a calculation for a control valve on a pump to close. That is the time used for this property. Since the value entered is calculated from the start of the model run, and it will override the operating rule, it can affect the way the results look after computing the transient analysis. For instance, if you enter a value here of 0.5 seconds, the program will close the pump 0.5 seconds after the model run starts. These results will be reflected in the transient results.

If the control valve is a check valve, you will want to enter a value of zero seconds. If there is no valve on the pump at all, enter a very large number, like 999,999 seconds to assure that it will not affect your model run. Either way, the pump will then compute results based on the operating rule.