Ingersoll Rand X8I Mode D'emploi page 16

In another example, there is a four compressor system
that includes a compressor in the compressor 4 spot
that is used only as an emergency backup compressor.
To accomplish this, simply assign compressor 4 a lower
priority than any other compressor in the system:
1
1
Compressor 4 has priority 2, all other compressors have
priority 1
In a third example, there is a four compressor system
that includes a variable speed compressor designated
compressor 1 and a fixed speed compressor that is an
emergency backup assigned as compressor 4. To ensure
that compressor 1 is always at the front of the sequence
and compressor 4 is always at the end of the sequence,
set the priority as shown below:
1
1
Compressor 1 has priority 1, compressor 4 has priority 3
and all other compressors have priority 2
A last example involves another four compressor system
that will be assigned into two independently rotation
groups. Compressors 1 and 2 are given priority 1 and
compressors 3 and 4 are given priority 2. This results in
the rotation sequence shown below:
1
1
Two independently rotating compressor groups
Priority control will also work with ENER control
mode. Recall that ENER control automatically selects
the most efficient set of compressors to dynamically
match compressed air demand. Priority will force the
X8I controller to select from all "priority 1" compressors
and make sure that they are loaded in the sequence
before utilizing any priority 2 compressors. All priority
2 compressors must be utilized before priority 3
compressors can be loaded and so on. Priority allows
a system to be segregated to backup and primary use
compressors when using ENER control.
Note: Using the Priority function with ENER Control can
affect system efficiency.
TABLES AND THE PRESSURE SCHEDULE
The X8I operates based on settings that are
configured into one of three tables. Each table defines
the operational settings and sequence control mode
of the X8I. The X8I can be instructed to change among
the tables at any time based on the configuration of the
pressure schedule.
This functionality allows the X8I to switch among
multiple different system configurations without any
disruption to control. This is particularly useful in the case
of shift changes, or weekends when the system is to be
deactivated.
Each table consists of the following parameters which can
be set independently in each table:
• PH – High Pressure Setpoint
• PL – Low Pressure Setpoint
• Pm – Minimum pressure warning level
• SQ – Sequence Rotation Strategy
• 01 – Compressor 1 Priority
• 02 – Compressor 2 Priority
• 03 – Compressor 3 Priority
• 04 – Compressor 4 Priority
The "maximum" pressure fault level and the rotation
interval, or rotation time, are set independently in a
configuration menu and are unchanging regardless of the
table selected.
When the X8I is instructed to change between tables,
it will not abruptly change the system operating
parameters. The X8I will adjust the system target pressure
upward or downward to the next table's settings.
This transition will occur gradually to preserve energy
efficiency and safe, reliable control:
16