Bryant LEGACY 580J*20M Series, Installation Instructions Manual

Page: 45 / 56

45
Fig. 49 — 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 pow-
er 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. 49. Connect the 4-20 mA terminal to RTU Open J4-2 and
connect the SIG COM terminal to RTU Open J4-3. See Fig. 50.
Fig. 50 — RTU Open/Indoor CO
2
Sensor
(33ZCSENCO2) Connections
Outdoor Air Quality Sensor (P/N 33ZCSENCO2 plus weath-
erproof enclosure) — The outdoor air CO
2
sensor is designed to
monitor carbon dioxide (CO
2
) levels in the outside ventilation
air and interface with the ventilation damper in an HVAC sys-
tem. The OAQ sensor is packaged with an outdoor cover. The
outdoor air CO
2
sensor must be located in the economizer out-
side air hood.
Fig. 51 — Outdoor Air Quality Sensor Cover
Wiring the Outdoor Air CO
2
Sensor — A dedicated power
supply is required for this sensor. A two-wire cable is required to
wire the dedicated power supply for the sensor. The two wires
should be connected to the power supply and terminals 1 and 2.
To connect the sensor to the control, identify the positive (4 to
20 mA) and ground (SIG COM) terminals on the OAQ sensor.
Connect the 4 to 20 mA terminal to RTU Open J4-5. Connect
the SIG COM terminal to RTU Open J4-6. See Fig. 52.
Fig. 52 — RTU Open / Outdoor CO
2
Sensor
(33ZCSENCO2) Connections
Space Relative Humidity Sensor or Humidistat
NOTE: The accessory space relative humidity sensor and hu-
midistat do not apply to size 30 units.
Perfect Humidity™ Control Wiring — In units equipped
with the Perfect Humidity 580J option there are two pink (PNK)
wires loose in the control box used to control the dehumidification
function of the unit. These pink wires are meant to be tied to a
space humidistat or thermidistat on an electromechanical unit. On
RTU Open equipped units these pink wires must be connected to
J11-7 and 8 to allow the Open board to operate the dehumidifica-
tion function for the unit. Disconnect the J11 Phoenix style con-
nector from the board and use the plug screws to secure the pink
wires in pins 7 and 8, reconnect the plug to the board at J11.
Relative Humidity Sensors (Space or Duct Mounted) — The
accessory space humidity sensor (33ZCSENSRH-01) or duct hu-
midity sensor (33ZCSENDRH-01) is used to measure the relative
humidity of air within the space or return air duct. The RH reading
is used to control the Perfect Humidity option of the rooftop unit.
For wiring distances up to 500 ft (152 m), use a 3-conductor, 18 or
20 AWG shielded cable. The shield must be removed from the
sensor end of the cable and grounded at the unit end. The current
loop power for sensor is provided by the RTU Open controller as
24 vdc. Refer to the instructions supplied with the RH sensor for
the electrical requirements and terminal locations. RTU Open con-
figurations must be changed after adding an RH sensor. See
Fig. 53 and 54 for typical RH sensor wiring.
• J4-1 or J4-4 = 24vdc loop power
• J4-2 or J4-5 = 4-20mA signal input
8 7 6 5 4 3 2 1 2 1
H G 24 VAC
OR
24 VDC
NC ALARM
RELAY
CONTACT
S
COM
NO
}
0-10VDC
S IG COM
4-20mA
+
+
-
+ -
J 3 J4
4-20mA
SIG COM
J4-2
J4-3
IAQ Sensor
24 VAC
COVER REMOVED S IDE VIEW
4-20mA
SIG COM
J4-5
J4-6
OAQ Sensor/RH Sensor
24 VAC