General Information
RT-SVX24J-EN
11
contacts to satisfy the applicable request for economizing,
mechanical cooling, heating, and ventilation. Refer to the
following discussion for an explanation of each module
function.
Rooftop Module (RTM - Standard on all units)
The rooftop Module (RTM) responds to cooling, heating,
and ventilation requests by energizing the proper unit
components based on information received from other
unit modules, sensors,
remote panels, and customer supplied binary inputs. It
initiates supply fan, exhaust fan, exhaust damper
positioning or variable frequency drive output, and
economizer operation based on
that information.
Compressor Module (MCM - standard on all
units)
The Compressor module, upon receiving a request for
mechanical cooling, energizes the appropriate
compressors and condenser fans. It monitors the
compressor operation through feedback information it
receives from various protection devices.
Human Interface Module (HI - standard on all
units)
The Human Interface module enables the operator to
adjust the operating parameters for the unit using a 16 key
keypad. The 2 line, 40 character LCD screen provides
status information for the various unit functions as well as
menus for the operator to set or modify the operating
parameters.
Heat Module (used on heating units)
The Heat module, upon receiving a request for Heating,
energizes the appropriate heating stages or strokes the
Modulating Heating valve as required.
Ventilation Override Module (VOM - Optional)
The Ventilation Override module initiates specified
functions such as; space pressurization, exhaust, purge,
purge with duct pressure control, and unit off when any
one of the five (5) binary inputs to the module are
activated. The compressors and condenser fans are
disabled during the ventilation operation. If more than one
ventilation sequence is activated, the one with the highest
priority is initiated.
Interprocessor Communications Board (IPCB -
Optional used with the Optional Remote
Human Interface)
The Interprocessor Communication Board expands
communications from the rooftop unit UCM network to a
Remote Human Interface Panel. DIP switch settings on the
IPCB module for this application should be; Switches 1 and
2 “Off”, Switch 3 “On”.
Lontalk®/BACnet® Communication Interface
Module (LCI/BCI - Optional - used on units
with Trane ICS™ or 3rd party Building
Automation Systems)
The LonTalk/BACnet Communication Interface modules
expand communications from the unit UCM network to a
TraneTracer Summit™ or a 3rd party building automation
system and allow external setpoint and configuration
adjustment and monitoring of status and diagnostics.
Exhaust/Comparative Enthalpy Module
(ECEM - Optional used on units with Statitrac
and/or comparative enthalpy options)
The Exhaust/Comparative Enthalpy module receives
information from the return air humidity sensor, the
outside air humidity sensor, and the return air temperature
sensor to utilize the lowest possible humidity level when
considering economizer operation. In addition, it receives
space pressure information which is used to maintain the
Table 1.
Resistance input vs. setpoint temperature
RTM cooling or
heating setpoint
input used as the
source for a ZONE
temp setpoint (°F)
RTM cooling
setpoint input
used as the source
for SUPPLY AIR
temp setpoint
cooling (°F)
Resistance (Ohms)
Max.
Tolerance 5%
40
40
1084
45
45
992
50
50
899
55
55
796
60
60
695
65
65
597
70
70
500
75
75
403
80
80
305
n/a
85
208
n/a
90
111
Table 2.
RTM resistance value vs. system operating
mode
Resistance applied to
RTM MODE input
Terminals (Ohms)
Max. Tolerance 5%
Constant Volume Units
Fan Mode
System Mode
2320
Auto
Off
4870
Auto
Cool
7680
Auto
Auto
10770
On
Off
13320
On
Cool
16130
On
Auto
19480
Auto
Heat
27930
On
Heat
