Bryant 548J - Manual (Page 40)

40
Outdoor Air Quality Sensor (PNO 33ZCSENCO2 plus
weatherproof 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 system. The OAQ sensor is packaged
with an outdoor cover. See Fig. 60. The outdoor air CO
2
sensor must be located in the economizer outside air hood.
COVER REMOVED SIDE VIEW
C07135
Fig. 60 -- 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. See Fig. 58. Connect the 4--20 mA terminal
to RTU--MP J4--5. Connect the SIG COM terminal to
RTU--MP J4--6. See Fig. 61.
SEN
COM
J4-5
J4-6
OAQ Sensor/RH Sensor
24 VAC
C08463
Fig. 61 -- RTU--MP / Outdoor CO
2
Sensor
(33ZCSENCO2) Connections
On 548J 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. 42 for unit
smoke detector wiring.
The Fire Shutdown Switch configuration,
MENU → Config → Inputs → input 5, identifies the
normally open status of this input when there is no fire
alarm.
Alarm state is reset when the smoke detector alarm
condition is cleared and reset at the smoke detector in the
unit.
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 → Config → Inputs → input 3, 5, 8, or 9
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, Fig. 47 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 fan status by setting
MENU → Config → Inputs → input 3, 5, 8, or 9 to Fan
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, Fig. 47, and Fig. 48 for wire terminations at J5.
Remote Occupancy
The remote occupancy accessory is a field--installed
accessory. This accessory overrides the unoccupied mode
and puts the unit in occupied mode. When installing this
accessory, the unit must be configured for remote
occupancy by setting MENU → Config → Inputs → input 3,
5, 8, or 9 to Remote Occupancy and normally open (N/O)
or normally closed (N/C).
Also set MENU
→ Schedules → occupancy source to DI
on/off. Input 8 or 9 is recommended for easy of
installation. Refer to Fig. 46 and Table 14 for wire
terminations at J5.
Power Exhaust (output)
Connect the accessory Power Exhaust contactor coil(s) per
Fig. 62.
Power Exhaust
J11-3
C
TAN
GRA
PEC
CTB
THERMOSTAT
C08464
Fig. 62 -- RTU--MP Power Exhaust Connections
Space Relative Humidity Sensor -- The RH sensor is not
used with 548J models at this time.
Communication Wiring -- Protocols
General
Protocols are the communication languages spoken by
control devices. The main purpose of a protocol is to
communicate information in the most efficient method
possible. Different protocols exist to provide different
kinds of information for different applications. In the BAS
application, many different protocols are used, depending
548J