Operation In Teamwork Mode; Unit-To-Unit Network Wiring; Liebert Icom U2U Ethernet Network - Emerson Liebert CRV User Manual

12.0 O
PERATION IN
12.1

Unit-to-Unit Network Wiring

Liebert CRV's can be connected in a unit-to-unit, or U2U, configuration, which allows multiple units
to communicate with each other, sharing of local unit status and sensor readings. The U2U network
will allow up to 32 units to be connected within a single group and up to 99 different groups to exists
on the same physical network. Groups can be used to create zones of influence so that only the Liebert
CRV's serving a common area will work together and back each other up.
The U2U setup unlocks the use of Lead-Lag/Rotation, Cascade and Teamwork Modes 1, 2 and 3
Lead-lag/rotation allows a standby Liebert CRV to activate based on an alarm or on a rotation
based on time.
Cascade provides staging of the Liebert CRV's based on the actual temperature and its relation to
the temperature setpoint.
Teamwork Modes 1, 2 and 3
• No Teamwork: All units operate independently; using their local sensors.
• Teamwork Mode 1 (Parallel): All units use a shared temperature PI value for heating/cooling
control and a shared humidity PI for humidification/dehumidification.)
• Teamwork Mode 2 (Independent) Avoid units performing conflicting operations. For example: (a)
units are not allowed to heat if other units are cooling, and (b) units are not allowed to humidify if
other units are dehumidifying.
• Teamwork Mode 3 (Smart Aisle) All units use a shared fan speed PI value; and drive cooling from
local sensors.
12.2

Liebert iCOM U2U Ethernet Network

The Liebert iCOM U2U network must be isolated from other network traffic. The network switch(es)
that connect Liebert iCOM controls must be dedicated to supporting only Liebert iCOM
communication. The U2U network cannot be connected to the building or IT network. If U2U
communication is lost, all Liebert iCOM-controlled cooling units will continue to operate as
independent units.
The Liebert iCOM control can support up to 64 nodes on one network. An input/output board, large
display and large wall-mount display are each considered one node. Of the 64 nodes that may be
connected, no more than 32 may be input/output boards (32 cooling units).
Network communication can be configured during system startup by a Emerson-trained technician.
For technical issues contact:
Liebert Thermal Management Support
Telephone: 1-800-LIEBSRV (1-800-543-2378) option 3 M-F 8-5 EST
T M
EAMWORK ODE
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Operation in Teamwork Mode

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Liebert CRV
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