Section 3
SEQUENCING WITH VARIABLE SPEED DRIVE COMPRESSORS
12
at 101 psi. The system will normally cruise at 98-100 psi.
3.3 SETUP FOR MULTIPLE VSD COMPRESSORS
With pressure-controlled VSD circuits, configure all compressors by Sequence Hours or
Com Number, as desired. Enable the Max. Speed Input function. All but one of the com-
pressors will be full-loaded, thus limiting the pressure to the rated value of the machines.
With serial-controlled VSD circuits, configure all compressors by Sequence Hours or Com
Number, as desired. The Supervisors allow all machines to run at reduced speeds, to
match delivery to demand. Unneeded machines will be stopped automatically. If the com-
pressors are L (100 psi) machines, set the program points as listed below:
Target system pressure at discharge of compressors: 95 psi
Unload Setpoint 102
Load Delta 8
VSD Setpoint 98
Lowest Pressure 90
Recover Time 10 sec.
Parameters may require adjustment based on system capacity and application. Unload
Setpoint should NEVER be more than 2 psi above package rating. Note that the normal
load delta becomes narrower while operating a sequenced system; the settings above will
load at 95 and unload at 101 psi. The system will normally cruise at 97-99 psi.
To Next Page
Loading...
