Bryant 548J*17 D Series, Installation Instructions Manual

Page: 43 / 56

43
RTU Open Controller System
The RTU Open controller is factory--mounted in the 548J
unit’s main control box, to the right of the CTB. See
Fig. 42. Factory wiring is completed through harnesses
connected to the CTB. Field connections for RTU Open
sensors will be made at the PCB connectors on the RTU
Open board. The factory--installed RTU Open controller
includes the supply--air temperature (SAT) sensor. The
outdoor air temperature (OAT) sensor is included in the
FIOP/accessory EconoMi$er
R
2 package.
The RTU Open controller is an integrated component of the
Bryant rooftop unit. Its internal application programming
provides optimum performance and energy efficiency. RTU
Open controller enables the unit to run in 100% stand--alone
control mode or to run a Third Party Building Automation
System (BAS). On--board DIP switches allow you to select
your protocol (and baud rate) of choice among the four most
popular protocols in use today: BACnet*, Modbus
{
,
Johnson N2 and LonWorks**. (See Fig. 43.)
Refer to Table 22, RTU Open Controller Inputs and Outputs
for locations of all connections to the RTU Open board.
C14049
Fig. 42 -- 548J Control Box Component Locations
J4
J2 J1
J5 J5
J22
J17
J19
J14
J11
J22
J3
J13
J12
J15
J20
Network Comm
Configurable - Input_8
24 V
A
C
Configurable - Input_5
24 V
A
C
Configurable - Input_3
24 V
A
C
Input_9 (Humidistat)
24 V
A
C
24 V
A
C
Input _8 (Enthalpy)
AO-1 (ECON)
Gnd
(OA
T
)
Gnd
(SA
T)
Input_5 (SMK) Input_4
(R)
BO-5
(Y1)
BO-4
(Y2)
BO-3
(W1)
BO-2
(W2)
BO-1
(G)
Gnd Input_3
(X)
24 V
AC IN
+24 VDC
Input_2 (CO2/RH)
Gnd
+24 VDC
Input_1 (CO2/RH)
Gnd
Board Power
(AO-1)
0-10VDC
4-20mA
BO-6
(H) Dehumidification
BO-7
(Reversing Valve/High Speed Fan/Y3)
BO-8
(Power Exhaust)
LonWorks
Option Card
Port
Example set for
BACnet MS/TP
and 76.8K baud
(1, 2, and 4 ON)
Protocol Selector SPT (temp input) BACnet, Modbus, or N2
(LON connection J15) SPT (common)
SPT (offset input)
*Remove
both for 0-5V
AO-2
GND
(2-10V)
3-Volt
Lithium
Battery
BO-1 BO-2 BO-3 BO-4 BO-5
BO-6
BO-7
BO-8
VFD Output
C14162
Fig. 43 -- RTU Open Multi--Protocol Control Board
* BACnet is a registered trademark of ASHRAE (American Society of
Heating, Refrigerating and Air---Conditioning Engineers).
{ Modbus is a registered trademark of Schneider Electric.
** LonWorks is a registered trademark of Echelon Corporation.