# EMS - Limit maximum chiller capacity

Hi,

I want to setup an EMS program where i can change the maximum capacity of the chiller.

For example:

I have chiller 1 (water condensed) and chiller 2 (air condensed). both have a maximum capacity of 1 MW, but i want chiller 1 to follow the heating loads of the building.

If i have heating loads of 0,5 MW and cooling loads of 1 MW i want chiller 1 to work until 0,5 MW and chiller 2 also at 0,5 MW.

If i have heating loads of 1,5 MW and cooling loads of 1,2 MW i want chiller 1 to work until 1 MW and chiller 2 until 0,2 MW.

If i have heating loads of 0,3 MW and cooling loads of 1,2 MW, chiller 1 will work until 0,3 MW and chiller 2 at 0,9 MW, and so on.

Wich actuator i could use to do that?

I'm trying to use EnergyManagementSystem:InternalVariable Available,CHILLER 1,Chiller Nominal Capacity,[W]. For the heating loads i'm using a load profile so i'm trying to match the chiller capacity with the hourly heating load profile.

Your question is not clear to me: how did you model chiller to meet heating load? So you have one "chiller" for heating and the other for cooling? Or are you useing a CentralHeatPumpSystem, or what?