Trane IntelliPak SCRF 25, Инструкция по установке, эксплуатации и обслуживанию

Страница: 69 / 120

SCXF-SVX01Q-EN 69
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.
N No otte e:: 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 38. Economizer remote minimum position
input resistance
Input Resistance
Economizer Min. Position
0 - 30 ohms 0%
30 - 240 ohms 0-100% (linear)
240 - 350 ohms 100%
> 350 ohms N/A
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 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
C Co on nttrro ollss