This is a difficult question that I looked into once before. Because the chiller loop is scheduled, not the individual chillers, I think you would have to put the chiller on it's own separate loop. Then, attach it to the main chilled water loop via a heat exchanger. You could make the heat exchanger 100% efficient. You will have to somehow coordinate the setpoint managers for both chiller loops.
This is a difficult question that I looked into once before. Because the chiller loop is scheduled, not the individual chillers, I think you would have to put the chiller on it's own separate loop. Then, attach it to the main chilled water loop via a heat exchanger. You could make the heat exchanger 100% efficient. You will have to somehow coordinate the setpoint managers for both chiller loops.