Rtu Open Control System; Sensory/Accessory Installation - Bryant Preferred 549K 04-06 Service And Maintenance Instructions

RTU OPEN CONTROL SYSTEM

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 enables the unit to run in 100% stand-alone control mode
or a Third Party Building Automation System (BAS). On-
board DIP switches allow the user to select your protocol (and
baud rate) of choice among the four most popular protocols in
use today: BACnet, Modbus
See Fig. 49.
The RTU Open control is factory-mounted in the unit's main
control box, to the left of the UCB (unit control board). Factory
wiring is completed through harnesses connected to the UCB.
Field connections for RTU Open sensors will be made at the
PCB connectors on the RTU Open board. The factory-installed
RTU Open control includes the supply-air temperature (SAT)
sensor. The outdoor air temperature (OAT) sensor is included
in the FIOP/accessory EconoMi$er

Sensory/Accessory Installation

There are a variety of sensors and accessories available for the
RTU Open. Some of these can be factory or field installed, while
others are only field installable. The RTU Open controller may
1. LonWorks is a registered trademark of Echelon Corporation.
2. Modbus is a registered trademark of Schneider Electric.
3-Volt
Lithium
Battery
LonWorks
Option Card
Port
J15
Example set for
BACnet MS/TP
and 76.8K baud
(1, 2, and 4 ON)
Protocol Selector
, Johnson N2 and LonWorks
1
2 package.
®
Board Power
J4
BO-1 BO-2
J13
J12
*Remove
both for 0-5V SPT (common)
SPT (offset input)
Fig. 49 — RTU Open Control Module
also require connection to a building network system or building
zoning system. All field control wiring that connects to the RTU
Open must be routed through the raceway built into the corner
post of the unit or secured to the unit control box with electrical
conduit. The unit raceway provides the UL required clearance be-
tween high and low-voltage wiring. Pass the control wires through
the hole provided in the corner post, then feed the wires thorough
the raceway to the RTU Open. Connect the wires to the removable
PCB connectors and then reconnect the connectors to the board.
.
2
IMPORTANT: Refer to the specific sensor or accessory
instructions for its proper installation and for rooftop unit
installation refer to base unit installation instructions and the
unit's wiring diagrams.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury, death and/or equipment damage.
Disconnect and lockout/tag-out electrical power before
wiring the RTU Open controller.
J1 J2
BO-3 BO-4 BO-5
J22
AO-2
BO-6
GND
(0-10V or 2-10V)
BO-7
BO-8
J17
Network Comm
J19
J20
SPT (temp input) BACnet, Modbus, or N2
(LON connection J15)
28
WARNING
(AO-1)
0-10VDC
J3
4-20mA
J5 J5
J22
VFD Output/IDF Output
J11
BO-6
(H) Dehumidification
BO-7
(Reversing Valve/High Speed Fan/Y3)
BO-8
(Power Exhaust)
J14