47
Connect T--59:
The T--59 space sensor requires a
separate, isolated power supply of 24 VAC. See Fig. 50
for internal connections at the T--59. Connect the SEN
terminal (BLU) to the RTU Open controller at J20--1.
Connect the COM terminal (BRN) to J20--2. Connect the
SET terminal (STO or BLK) to J20--3.
OR
SET
SEN
OPB
COM- PWR+
BLU (SPT)
BLK (STO)
24 VAC
SENSOR
WIRING
POWER
WIRING
BRN (COM)
NOTE: Must use a separate isolated transformer.
J20-3
J20-2
J20-1
C10291
Fig. 50 -- Space Temperature Sensor Typical Wiring
(33ZCT59SPT)
Indoor Air Quality (CO
2
) Sensor —
The indoor air quality sensor accessory monitors space
carbon dioxide (CO
2
) levels. This information is used to
monitor IAQ levels. Several types of sensors are available,
for wall mounting in the space or in return duct, with and
without LCD display, and in combination with space
temperature sensors. Sensors use infrared technology to
measure the levels of CO
2
present in the space air.
The CO
2
sensors are all factory set for a range of 0 to
2000 ppm and a linear mA output of 4 to 20. Refer to the
instructions supplied with the CO
2
sensor for electrical
requirements and terminal locations. See Fig. 51 for
typical CO
2
sensor wiring schematic.
To accurately monitor the quality of the air in the
conditioned air space, locate the sensor near a return--air
grille (if present) so it senses the concentration of CO
2
leaving the space. The sensor should be mounted in a
location to avoid direct breath contact.
Do not mount the IAQ sensor in drafty areas such as near
supply ducts, open windows, fans, or over heat sources.
Allow at least 3 ft (0.9 m) between the sensor and any
corner. Avoid mounting the sensor where it is influenced
by the supply air; the sensor gives inaccurate readings if
the supply air is blown directly onto the sensor or if the
supply air does not have a chance to mix with the room air
before it is drawn into the return airstream.
8 7 6 5 4 3 2 1
2 1
H G 24 VAC
OR
24 VDC
NC
ALARM
RELAY
CONTACTS
COM
NO
}
0-10VDC
SIG COM
4-20mA
+
+
-
+ -
J3
J4
C08635
Fig. 51 -- Indoor/Outdoor Air Quality (CO
2
) Sensor
(33ZCSENCO2) -- Typical Wiring Diagram
Wiring the Indoor Air Quality Sensor:
For each sensor,
use two 2--conductor 18 AWG (American Wire Gage)
twisted--pair cables (unshielded) to connect the separate
isolated 24 vac power source to the sensor and to connect
the sensor to the control board terminals.
To connect the sensor to the control, identify the positive (4
to 20 mA) and ground (SIG COM) terminals on the sensor.
See Fig. 51. Connect the 4--20 mA terminal to the RTU
Open controller at terminal J4--2 and connect the SIG COM
terminal to the RTU Open controller at J4--3. See Fig. 52.
4-20mA
SIG COM
J4-2
J4-3
IAQ Sensor
24 VAC
C10738
Fig. 52 -- RTU Open / Indoor CO
2
Sensor
(33ZCSENCO2) Connections
Summary of Contents for 548J*17 D Series
Page 4: ...4 a548J 015 Fig 2 Unit Dimensional Drawing Size 17 Units ...
Page 5: ...5 a548J 016 Fig 2 Unit Dimensional Drawing Size 17 Units cont ...
Page 6: ...6 a548J 017 Fig 2 Unit Dimensional Drawing Size 17 Units cont ...
Page 7: ...7 a548J 018 Fig 3 Unit Dimensional Drawing Size 24 Units ...
Page 8: ...8 a548J 019 Fig 3 Unit Dimensional Drawing Size 24 Units cont ...
Page 9: ...9 a548J 020 Fig 3 Unit Dimensional Drawing Size 24 Units cont ...
Page 13: ...13 C10139 Fig 7 Roof Curb Details Size 17 Units ...
Page 14: ...14 C10140 Fig 8 Roof Curb Details Size 24 Units ...
Page 19: ...19 a50 9696 Fig 20 548J 17 24 Control Wiring Diagram with VFD Option ...
Page 20: ...20 a50 9697 Fig 21 Typical 548J 17 24 Power Wiring Diagram 208 230V 3 Phase 60Hz unit shown ...
Page 44: ...44 a50 9699 Fig 44 RTU Open System Control Wiring Diagram ...
