Unit Control 
 
1.2 Control Flowchart 
 
2 Main Control Logics 
2.1 Cooling 
2.1.1 Control to the Compressor 
When  the  unit  is  controlled  by  the  leaving  water  temperature,  the  operating  frequency  of  the 
compressor  will  be  adjusted  by  the  temperature  difference  in  the  way  that  it  increases  as  the 
temperature  difference  goes  up  and  it  decreases  as  the  temperature  difference  goes  down. 
(Temperature difference= actual leaving water temperature-leaving water temperature set point). 
2.1.2 Freeze Protection 
When it is detected that the leaving water temperature of the plate heat exchanger is lower than the 
freeze  protection  temperature,  the  compressor  will  drop  its  operating  frequency until  it  reaches  the