Operation in Teamwork Mode
137
Liebert
®
CRV
™
Figure 121 Teamwork Mode 1 with three cooling units
12.4.4 Teamwork Mode 2
Teamwork Mode 2 is designed to prevent units within a group from working in opposing modes,
effectively “fighting” each other. It is best applied in large rooms with unbalanced heat loads. In
Teamwork Mode 2, all temperature and humidity parameters are shared. Unit #1 takes a
user-defined average or maximum sensor reading on the network to determine whether there is a
cooling, dehumidification or humidification request. To further improve control output, when the
Liebert iCOM is set to control off an average, the number of units calculated in the average can be set
lower than the total number of units connected. This provides a more defined control strategy, by
taking into account only the worst case readings.
If there is a cooling request, all units are released to start cooling resources according to their own
temperature readings; and operate cooling off their own unique temperature control bands. If some of
the units sense a cooler temperature, they are permitted to reduce cooling to keep from cooling the
space beyond the temperature setpoint. If the master determines the greatest demand is for
dehumidification, the units that require dehumidification are released to operate in that mode. Units
in the group that may have only a small request for humidification will the remain idle for maximum
energy saving and control.
Teamwork Mode 2 does not rotate; unevenly distributed working hours to be expected. AutoSet will
not adjust the proportional band in this mode.
NOTE
The Liebert CRV is designed to use Teamwork Mode 3 where three 2T sensors are supplied to
monitor the temperature at the racks and ramp the fans accordingly.
NOTE
In Teamwork Mode 2, all units must have the same setpoints. The units’ proportional band,
deadband and related settings may be different.
Shared System Deviation Ramp (System CFC)
0%
+33 %
+66 %
+100 %
100 %
0%
100 %
100 %
0%
20%
System CFC
Fanspeed
Compressors
Chilled Water Valves
Summary of Contents for Liebert CRV
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