Trane ReliaTel - Reliatel Economizer Layout (RTEM)

RT-SVD03G-EN 97
ReliaTel Economizer Layout (RTEM)
The RTEM Module plugs directly onto the actuator. It has a diagnostic LED, which under normal
operation is either ON (OK to economize) or FLASHING (not OK to economize). It communicates
via MODBUS with the RTRM, and receives an outside air temperature input from the RTRM. Mixed
air sensor (MAS), return air sensor (RAT), outdoor humidity sensor (OHS), and return humidity
sensor (RHS) are all plugged directly into the RTEM. The application section of this manual shows
how to apply a CO2 sensor.
A stripped down version of the RTEM, which only contains the MAT input, Design min. pos.
adjustment, Remote Min Position input, Enthalpy Setpoint, and the wire plug for power and
ModBus communications, is also available. This module will only be applied on units that are
supplied from the factory without any economizer options such as, Reference Enthalpy,
Comparative Enthalpy or C02. Options installed in the field will require the "full-up" version in order
to operate properly.
• To read the actual damper position, read the DC voltage at the ’2-10 vdc Damper Position’ input
terminals; 2 vdc is closed, 10 vdc is 100% open.
• To drive 2 actuators with 1 control, connect field wiring as shown in Figure 59, p. 98.
Note: Remote minimum position input does not work when a CCP is controlling the unit.
Figure 58. Reliatel Economizer Module Layout (RTEM)
COMMUNICATIONS FAILURE
MAT SENSOR FAULT
OAT SENSOR FAULT
OAH SENSOR FAULT
RAT SENSOR FAULT
RAH SENSOR FAULT
CO2 SENSOR FAULT
ACTUATOR FAULT
NORMAL - NOT OK TO ECONOMIZE
NORMAL - OK TO ECONOMIZE
NO POWER
BLINK
8
7
6
4
3
2
1
STEADY FLASH
STEADY ON
OFF
LED FLASH CODES
24
VAC
24
VAC
XFMR
1
MBUS
2 - 10 VDC
DAMPER
OVERRIDE
2 - 10 VDC
DAMPER
POSITION
2000
1500
UL
1000
500
1900
LL
300
Pre-RTRM V. 8
DCV
SETPOINT
RTRM V. 8 or Newer
E
D
C
B
A
ENTHALPY
SETPOINT
DESIGN
DCV
MIN
POS
DCV
MODE
P 1 P
DCV
RAH
RAT
OAT
OAH
MAT
ExF
..
Green LED
.
.
.
.
.
.
Remote
Minimum
Potentiometer
.
.
.
.
WHT
.
RED
.
BLUE
.
.
.
.
.
.
.
.
.
.
.
.
.
.
1
2
1
2
1
2
1
2
1
2
1
2
1
2
Power Exhaust
Contacts
Mixed Air Sensor Input
Common
Common
OHS Input
Not used - OAT is
connected to RTRM
Common
RA Input
Common
RHS Input
Common
CO
2 Sensor Input
Shorted - Force closed
Open = On Board Pot.
270Ω = 50%