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shall be provided for all 24 volt control
functions. The resident control algorithms
shall make all heating, cooling and/or
ventilating decisions in response to
electronic signals from sensors
measuring indoor and outdoor
temperatures. The control algorithm
maintains accurate temperature control,
minimizes drift from set point and
provides better building comfort. ReliaTel
controls shall provide anti-short cycle
timing and time delay between
compressors to provide a higher level of
machine protection.
Control Options
Inlet Guide Vanes shall be installed on
each fan inlet to regulate capacity and
limit horsepower at lower system
requirements. When in any position
other than full open they shall pre-spin
intake air in the same direction as fan
rotation. The inlet guide vanes shall
close when supply fan is off, except in
night setback.
The inlet guide vane actuator motor shall
be driven by a modulating dc signal
from the unit controls. A pressure
transducer shall measure duct static
pressure and modulate the inlet guide
vanes to maintain the required supply air
static pressure within a predetermined
range.
Variable Frequency Drives (VFDs)
VFDs shall be factory installed and tested
to provide supply fan motor speed
modulation. The VFD shall receive a 2-
10 VDC signal from the unit controls
based upon supply static pressure and
shall cause the drive to accelerate or
decelerate as required to maintain the
supply static pressure setpoint. When
subjected to high ambient return
conditions the VFD shall reduce its output
frequency to maintain operation. Bypass
control to provide full nominal air flow in
the event of drive failure shall be optional.
Ventilation Override
Ventilation Override shall allow a binary
input from the fire/life safety panel to
cause the unit to override standard
operation and assume one of two factory
preset ventilation sequences, three
factory preset ventilation sequences,
exhaust, pressurization or purge. The
74
Mechanical
Specifications
three sequences shall be selectable
based open a binary select input.
Trane Communication Interface (TCI)
Shall be provided to interface with the
Trane Integrated Comfort™ System and
shall be available field or factory-installed.
The TCI shall allow control and monitoring
of the rooftop unit via a two-wire
communication link.
The following alarm and diagnostic
information shall be available:
RTRM Originated Data
• Unit operating mode
• Unit failure status
Cooling failure
Heating failure
Emergency service stop indication
Supply fan proving
Timed override activation
High temperature thermostat status
• Zone temperature
• Supply air temperature
• Cooling status (all stages)
• Stage activated or not
• Stage locked out by RTRM
• HPC status for that stage
• Compressor disable inputs
• Heating status
• Number of stages activated
• High temperature limit status
• Economizer status
• Enthalpy favorability status
• Requested minimum position
• Damper position
• Dry bulb/enthalpy input status
• Outside air temperature
• Outside relative humidity
• Sensor Failure
Humidity sensor
OAT sensor
SAT sensor
RAT sensor
Zone temperature sensor
Mode input
Cooling/heating setpoints from sensors
Static pressure transducer
Unit mounted potentiometer
SAT from potentiometer
Air reset setpoint from potentiometer
• Unit Configuration data
Gas or electric heat
Economizer present
• High temp input status
• Local setpoint
• Local mode setting
• Inlet Guide Vane position
• Clogged filter service indicator
setpoint
• CO
2
• CO
value
2
Tracer Originated Data
• Command operating mode
• Host controllable functions:
Supply fan
Economizer
Cooling stages enabled
Heating stages enabled
Emergency shutdown
• Minimum damper position
• Heating setpoint
• Cooling setpoint
• Supply air tempering enable/disable
• Slave mode (CV only)
• Tracer/Local operation
• SAT setpoint
• Reset setpoint
• Reset amount
• MWU setpoint
• MWU enable/disable
• SAT Reset type select
• Static pressure setpoint
• Static pressure deadband
• Daytime warm-up enable/disable
• Power exhaust setpoint
LonTalk Communication Interface (LCI-R)
The field or factory-installed ReliaTel®
LonTalk Communication Interface (LCI-R)
will be provided to interface with the
Trane Integrated Comfort System or
LonTalk capable third party building
management networks. The LCI-R will
allow control and monitoring of the
rooftrop unit via a two-wire
communication link.
Outside Air
Manual Outside Air
A manually controllable outside air
damper shall be adjustable for up to 25
percent outside air. Manual damper is
set at desired position at unit start up.
Economizer
Economizer shall be factory installed.
The assembly includes: fully modulating
0-100 percent motor and dampers,
minimum position setting, preset
linkage, wiring harness, and fixed dry
bulb control. Solid state enthalpy and
differential enthalpy control shall be a
factory or field installed option.
RT-PRC007-EN
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