Ingersoll-Rand ReliaTel, Manual, Page: 164 / 176

164 RT-SVD03L-EN
Constant Volume (CV) and Variable Air Volume (VAV)
Constant Volume (CV)
These units may use a conventional thermostat or zone
sensor. The units can be controlled using a LonTalk
®
Communications Interface (LCI) or Tracer ® Summit.
Every unit comes with an RTRM and RTOM. All other
circuit boards are optional depending upon unit
configuration.
Variable Air Volume (VAV)
VAV units use the same circuit boards as CV models,
but operation and in some cases troubleshooting, are
significantly different. The following sections contain
operating and troubleshooting information on VAV
units. Every unit comes with an RTRM, RTOM, and
RTAM. Additional information can be found in the
Installation Operation and Maintenance (IOM) guide for
your unit.
VAV with ReliaTel ™ ™ versus VAV with
UCP
ReliaTel
™
units do everything UCP units did and more.
Here are some differences between UCP and ReliaTel ™
units:
VAV setpoint panel: ReliaTel ™ has the same setpoints
as UCP but they are mounted on (and integral to) the
RTAM module. Also, every setpoint can be provided
remotely by clipping the appropriate jumper and using
the terminal strip on the RTAM.
Exhaust fan setpoint panel: ReliaTel ™ exhaust fan
setpoint potentiometer is located on the RTOM module
in the main control box.
Zone sensor and NSB inputs: With ReliaTel ™ , these
inputs are located on the RTRM module instead of
LTB1 (UCP).
N No otte e:: The thermostat inputs on the RTRM are ignored.
These inputs are for CV units only.
Emergency stop: This input, called ESTOP, is located
on LTB1-5 and LTB1-6 instead of LTB1-16 and LTB1-17
(UCP).
ReliaTel ™ modules communicate with each other on a
ModBus link. Each module has a status LED indicating
that the module is communicating with the link.
RTRM - ReliaTel ™ ™ Refrigeration Module -
(Standard)
This is the primary control module. It has built-in
terminal strips for zone sensor, thermostat, and night
setback connections as well as diagnostic outputs for
service. In addition, the RTRM has the following inputs
and outputs:
• Compressor outputs
• Outdoor fan relay outputs
• Low pressure (LPC) inputs
• Outdoor air sensor (OAS) input
• Supply fan output
• Electric heat outputs (TE* only)
• TEST mode input
• Emergency stop input
N No otte e:: There is only one module used for 27.5 to 50
ton units regardless of configuration (VAV,
CV). The unit is configured by wire harness
inputs. See the unit wiring diagram for
details.
RTOM - ReliaTel ™ ™ Options Module -
(Standard)
This module has inputs for the following:
• Ventilation override (LTB4)
• Frostat ™ input
• Clogged filter switch (optional)
• Discharge air sensor (optional on CV, standard on
VAV)
N No otte e:: Discharge air sensor required with CCP/ICS
RTAM - ReliaTel ™ ™ Air Handler Module -
(Standard on VAV)
This module contains the VAV setpoint potentiometers
as well as the following inputs and outputs:
• DIP switch inputs for supply air reset, daytime
warm-up enable, and IGV/VFD configuration.
• Supply pressure transducer input inlet guide vane
(IGV) or variable frequency drive (VFD) output.
• Ventilation heat relay (VHR) output.
ECA - Economizer Actuator - (Optional)
If the unit has an economizer this module is present. It
is screwed to the top of the economizer actuator motor
in the economizer section of the unit. The ECA has the
following inputs and outputs:
• Mixed air sensor - this sensor is located in the
supply air section of the unit.
• Return air sensor (optional) - This sensor is used
when the unit has comparative enthalpy.
• Return humidity sensor (optional) - this sensor is
used when the unit has comparative enthalpy.
• Outdoor humidity sensor (optional) - this sensor is
used when the unit has reference enthalpy or
comparative enthalpy.
• Exhaust fan relay output.