Auto. Restart After Pow er Failure

When an autorestart cond ition occurs, each chi ller m ay ha ve a delay added to the star t-u p
sequence, dependin g on it s lead/lag configurat ion. The lead chiller does no t have a delay. The
lag chiller has a 45-second dela y. The standby chiller has a 90-seco nd delay. The delay time is
added after the chiller wat er flow verificatio n. The PIC controls ensure that th e guide vanes are
closed. After the guide v an e position is confirm ed, the delay for lag and standb y ch ill er occurs
prior to energizing th e oil pump. The normal star t-up sequence then cont inues. The auto. restar t
delay sequence occurs whether the chiller is in CCN or LOCAL mode and is inten ded to stagger
the compressor motors fro m being energized simul taneously. This will hel p reduce the inrush
demands on the building power system.
Ice Build Control
Ice build control autom at ically sets the chilled W A TER /BRINE CONTROL POINT of the
machine from normal ope ration set point tempera ture to a temperature where an ice building
operation for therma l s to rage can be accomplished .
Note: For ice build control to pr ope rly operate, the PIC con tro ls must be placed in CCN mod e.
See Figure 16 and Figure 17.
The PIC can be configured for ice build oper ation. Configurat ion of ice bui ld control is
accomplished throu gh en tries in the Config tabl e, Ice Build Setpoint table , an d the Ice Build
Time Schedule table. Figure 16 and Figure 17 show how to access each entry.