Carrier 50TCQD Installation Instructions Manual page 32

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 present in the space air.
2
The CO sensors are all factory set for a range of 0 to
2
2000 ppm and a linear mA output of 4 to 20. Refer to the
instructions supplied with the CO
requirements and terminal locations. See Fig. 37 for
typical CO sensor wiring schematic.
2
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
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.
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 RTU- - MP 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. 37. Connect the 4- - 20 mA terminal to
RTU- - MP J4- - 2 and connect the SIG COM terminal to
RTU- - MP J4- - 3. See Fig. 52.
IAQ Sensor
SEN
COM
24 VAC
Fig. 52 - - RTU- - MP / Indoor CO
(33ZCSENCO2) Connections
Outdoor Air Quality Sensor (PNO 33ZCSENCO2 plus
weatherproof enclosure) — The outdoor air CO
designed to monitor carbon dioxide (CO
outside ventilation air and interface with the ventilation
damper in an HVAC system. The OAQ sensor is packaged
with an outdoor cover. See Fig. 39. The outdoor air CO
sensor must be located in the economizer outside air hood.
Wiring the Outdoor Air CO
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.
sensor for electrical
2
J4-2
J4-3
C08462
Sensor
2
sensor is
2
) levels in the
2
Sensor — A dedicated power
2
To connect the sensor to the control, identify the positive
(4 to 20 mA) and ground (SIG COM) terminals on the
OAQ sensor. See Fig. 37. Connect the 4 to 20 mA
terminal to RTU- - MP J4- - 5. Connect the SIG COM
terminal to RTU- - MP J4- - 6.
OAQ Sensor/RH Sensor
2
24 VAC
Fig. 53 - - RTU- - MP / Outdoor CO
(33ZCSENCO2) Connections
On 50TCQD units equipped with factory- - installed Smoke
Detector(s), the smoke detector controller implements the
unit shutdown through its NC contact set connected to the
unit's CTB input. The FSD function is initiated via the
smoke detector's Alarm NO contact set. The RTU- - MP
controller communicates the smoke detector's tripped
status to the BAS building control. See Fig. 48, the
RTU- - MP System Control Wiring diagram.
The Fire Shutdown
MENU Config Inputs
→ →
normally open status of this input when there is no fire
alarm.
Connecting Discrete Inputs
Filter Status
The filter status accessory is a field- - installed accessory.
This accessory detects plugged filters. When installing
this accessory, the unit must be configured for filter status
by setting MENU
→
to Filter Status and normally open (N/O) or normally
closed (N/C). Input 8 or 9 is recommended for easy of
installation. Refer to Fig. 46 and Fig. 48 for wire
terminations at J5.
Fan Status
The fan status accessory is a field- - installed accessory.
This accessory detects when the indoor fan is blowing air.
When installing this accessory, the unit must be
configured for
MENU Config Inputs
→ →
Status and normally open (N/O) or normally closed (N/C).
Input 8 or 9 is recommended for easy of installation. Refer
to Fig. 46 and Fig. 48 for wire terminations at J5.
2
32
SEN
COM
Sensor
2
Switch configuration,
input 5, identifies
→
Config Inputs input 3, 5, 8, or 9
→ →
fan status by
input 3, 5, 8, or 9 to Fan
→
J4-5
J4-6
C08463
the
setting