PIC System Functions
Note: Throughout this manual, words printed in capital letters and italics are values that may be viewed on the LID. See Table 2 for examples of LID screens. Point names are listed in the Description column. An overview of LID operation and menus is given in Figure 13, Figure 14, Figure 15, Figure 16, Figure 17, Figure 18, and Figure 19.
Capacity Control
The PIC controls the machine capacity by modulating the inlet guide vanes in response to chilled water temperature changes away from the CONTROL POINT. The CONTROL POINT may be changed by a CCN network device, or is determined by the PIC adding any active chilled water reset to the chilled water SET POINT. The PIC uses the PROPORTIONAL INC (Increase) BAND, PROPORTIONAL DEC (Decrease) BAND, and the PROPORTIONAL ECW (Entering Chilled Water) GAIN to determine how fast or slow to respond. CONTROL POINT may be viewed/overridden on the Status table, Status01 selection.
Entering Chilled Water Control
If this option is enabled, the PIC uses ENTERING CHILLED WATER temperature to modulate the vanes instead of LEAVING CHILLED WATER temperature. ENTERING CHILLED WATER control option may be viewed/modified on the Equipment Configuration table, Config table.
