99 
 
 
 
NOTE: For first stage, rotate coupling clockwise to close guide vanes; rotate coupling counterclockwise to open guide vanes. 
            For second stage, rotate coupling counterclockwise to close guide vanes; rotate coupling clockwise to open guide vanes. 
 
 
 
1 : actuator 
2 : Connector 
3 : Set screw 
4 : Bracket 
5 : Coupling 
6 : Holddown bolts and washers 
 
The guide vane actuator wiring of 19DV is as below : 
 
 
 
Fig 55 – IGV actuator details 
 
9.1.10 Trim Refrigerant Charge 
If to obtain optimal chiller performance it becomes necessary to adjust the refrigerant charge, operate the chiller at 
design  load  and  then  add  or  remove  refrigerant  slowly  until  the  difference  between  the  leaving  chilled  water 
temperature and the cooler refrigerant temperature reaches design conditions or becomes a minimum.  
Do not overcharge. Use cooler sight glass to check the liquid level. The level must be in the middle of sight glass 
for correct refrigerant charge in operation. During steady state operation at 80-100% of capacity, the boiling pool