CDHF-SVU01C-EN
20
General
Information
Simultaneous Compressor Start/
Stop
Both compressors will start in close
succession to minimize the time it
takes for the chiller to reach full load.
Some process applications need the
chiller to start and generate capacity
as fast as possible. This method will
start both compressors, slightly
staggered to prevent doubling of the
current inrush, but will generally
control the chiller as if there were
only one compressor.
If the chiller is in the Auto mode and
all interlocks have been satisfied,
compressor 1 will be started based
on the leaving water temperature
rising above the “Differential to Start”
setting. When compressor 1 is at
speed, compressor 2 will start. Both
compressors will run until water
temperature falls below the
differential to stop, at that time both
compressors will be shut down.
Figure 15. CDHF/G sequence of operation: combined start