RT-PRC031-EN 21
Controls VAV and CV
If there is a call for economizer
cooling, the outdoor air damper may
be opened further to satisfy the
cooling request.
If the space CO2 level is greater than
the CO2 Minimum Setpoint and less
than the CO2 Design Setpoint, the
outdoor air damper position is (or OA
flow) modulated proportionally to the
Space CO2 level relative to a point
between the CO2 Min Setpoint and
the CO2 Design Setpoint. If there is a
call for economizer cooling, the
outdoor air damper may be opened
further to satisfy the cooling request.
See Figure 14, p.21
Humidification Control
A relay output is provided to control
an externally connected, field
supplied humidifier. Logic is
provided for Occupied and
Unoccupied humidification control
with safeguards to prevent cycling
between humidification and
dehumidification
Return Fan Control
A return fan reduces the load on the
supply fan motor or can allow a unit
to operate at a higher static pressure.
The return fan VFD is modulated
independently to maintain desired
return air plenum pressure. In all

Figure 14. CO2 Control

OA Dam

p

er Minimum

CO2 Level

CO2 Min
Setpoint CO2 Design
Setpoint
DCV Min
OA
Damper
Setpoint
Design
Min OA
Damper
Setpoint
Min OA
Damper
Position
Target
Space CO2 Level
other cases the return fan is turned
on or off with the supply fan.
LonTalk® Building Automation System
The LonTalk Communication
Interface for IntelliPak II (LCI-I)
controller expands communications
from the unit UCM network to a
Trane Tracer Summit or a 3rd party
building automation system, utilizing
LonTalk, and allows external setpoint
and configuration adjustment and
monitoring of status and diagnostics.
The LCI-I utilizes an FTT-10A Free
Topology transceiver, which supports
non-polarity sensitive, free topology
wiring, which allows the system
installer to utilize star, bus, and loop
architectures.This controller works in
standalone mode, peer-to-peer with
one or more other units, or when
connected to a Trane Tracer Summit
or a 3rd party building automation
system that supports LonTalk. The
LCI-I controller is available as a
factory or field-installed kit.
Twinning
Twinning is a Master Unit and one, or
more, similarly configured Slave
Unit(s) operating cooperatively, as a
group, to provide higher capacity
and/or redundancy at partial capacity.
Twinning requires an LCI module
installed in each unit and is
accomplished by binding variables
between unit communication
modules, communicating common
setpoints and conditions
(temperatures, pressures, fan
speeds, damper positions,
occupancy, states, etc.) and allowing
each unit to run independent
algorithms.
Twinned units must share a common
supply and return duct network.
Twinned units operate:
a. as part of a Trane ICS™
installation, with Tracer
Summit
b. on an interoperable project
with a 3rd party LonTalk
c. as an independent group
(bound via Rover® or 3rd
party tool).