Rtm Module Board-Standard On All; Units - Trane Technologies IntelliPak Signature SCWF Installation, Operation And Maintenance Manual

Controls
RTM Module Board—Standard on all

Units

The 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, or
variable frequency drive output, and airside economizer
operation based on that information.
Reference the RTM points list on page 70.
Note: Emergency stop and external auto/stop, stop the unit
immediately, emergency stop generates a manual
reset diagnostic that must be reset at the unit human
interface. External auto-stop will return the unit to
the current operating mode when the input is closed,
so this input is auto reset.
RTM Remote Economizer Minimum Position
The remote minimum position potentiometer,
BAYSTAT023A, provides a variable resistance (0-270
ohms) to adjust the economizer minimum position from 0 to
100% when connected to the economizer remote minimum
position input of the RTM. The RTM must be selected as
the source for economizer minimum position. If the RTM is
the selected source for economizer minimum position, and
if a valid resistance per the table below is provided to the
RTM remote minimum position input, the OA cfm
compensation function will not operate, even if enabled.
"Default" is the only possible source for economizer
minimum position when using the OA cfm compensation
function.
Table 31. Economizer remote minimum position input
resistance
Input Resistance
0 - 30 ohms
30 - 240 ohms
240 - 350 ohms
> 350 ohms
Note: A resistance greater than 350 ohms is assumed to be an open
circuit. The system will use the default minimum position value.
RTM Analog Outputs
The RTM has two 0-10 Vdc outputs: one for the supply fan
and one for the economizer option. These outputs provide
a signal for one or two damper actuators. There are no
terminal strip locations associated with these wires. They
go directly from pins on RTM circuit board to actuator
motor.
RTM Binary Outputs
The RTM has an output with pressure switch proving inputs
for the supply fan. There is a 40 second delay from when
the RTM starts the supply fan until the fan proving input
must close. A fan failure diagnostic will occur after 40
62
Economizer Min. Position
0%
0-100% (linear)
100%
N/A
seconds. This is a manual reset diagnostic, and all heating,
cooling, and economizer functions will shut down. If this
proving input is jumped, other nuisance diagnostics will
occur. If the proving input fails to close in 40 seconds, the
economizer cycles to the minimum position. This is a
manual reset diagnostic. External control of the fan is not
recommended.
VAV Drive Max Output
This is a single-pole, double-throw relay rated at a
maximum voltage of 24 Vac, two amps. The relay contacts
of this relay switch when the unit goes from the occupied
mode to the unoccupied mode by means of the occupied
binary input. The contacts will stay switched during the
unoccupied and morning warm-up mode. They will return
to the position shown on the unit wiring diagram when the
unit returns to the occupied mode. This binary output
signals the VAV boxes or other terminal devices to go full
open.
RTM Alarm Relay
This is a single pole, double throw relay rated at a
maximum voltage of 24 Vac, two amps max. Relay
contacts can be programmed from the unit human
interface. This relay can be programmed to pick up on any
one or group of diagnostics from the unit human interface.
Status/Annunciator Output
The status annunciator output is an internal function within
the RTM module on CV and VAV units. It provides:
• Diagnostic and mode status signals to the remote panel
(LEDs) and to the Human Interface.
• Control of the binary alarm output on the RTM.
• Control of the binary outputs on the GBAS module to
inform the customer of the operational status and/or
diagnostic conditions.
Occupied/Unoccupied Inputs
There are four (4) ways to switch to occupied/unoccupied:
• Field-supplied contact closure hard wired binary input
to the RTM.
• Programmable night setback zone sensor.
• Tracer Summit.
• Factory-mounted time clock.
VAV Changeover Contacts
These contacts are connected to the RTM when daytime
heating on VAV units with internal or external hydronic heat
is required. Daytime (occupied) heating switches the
system to a CV unit operation. Refer to the unit wiring
diagram for the field connection terminals in the unit control
panel. The switch must be rated at 12 mA @ 24 Vdc
minimum.
External Auto/Stop Switch
A field-supplied switch may be used to shut down unit
operation. This switch is a binary input wired to the RTM.
SCXF-SVX01T-EN