There is an option for ?Load-Reset? which will vary the chilled water supply temperature based on load. You will not need a schedule for the control option.

To verify if you set point is working I suggest you create hourly variable outputs of leaving chilled water temperature, entering condenser water (if applicable), chiller assigned loads, and chiller electricity. You can calculate the kw/ton for each condition and see where you are not getting your expected results. If you are trying to model a specific chiller then you will have to generate custom curves to get the correct efficiency at each supply temperature.

John Grando BEMP | CEM | LEED AP BD+C