Chiller stop to operate when I changed Pump:ConstantSpeed to Pump:VariableSpeed

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I have model with primary constant secodary variable plant loop.
According to design change, I tried to change the constant speed pump to variable speed pump for primary loop in idf editor.
What I did is only following.
1. Change Pump:ConstantSpeed to Pump:VariableSpeed
2. Change Component 1 Object Type from Pump:ConstantSpeed to Pump:VariableSpeed as shown below image
By this method, simulation itself could run. But found that chiller is not operating.
Does anyone know what I should have done to work this case correctly?