Bryant 580J 04-30, 558J 04-30, 548J 04-24581J 04-28, 549J 04-12, 551J 04-28 Controls, Start-up, Operation And Troubleshooting
580J/558J*04- 30, 548J*04-24
581J/551J*04- 28, 549J*04-12
Factory Installed Option
RTU Open
Controls, Start- Up, Operation,
and Troubleshooting
TABLE OF CONTENTS
SAFETY CONSIDERATIONS 2.........................
GENERAL 2.........................................
SENSOR/ACCESSORY INSTALLATION 2................
Sensors and Accessories 4.............................
User Interfaces 4.....................................
Install Analog Sensors 4...............................
Supply Air Sensor (SAT) 4...........................
Outdoor Air Sensor (OAT) 4..........................
Space Temperature Sensor (SPT) 4.....................
Sensor(s) (IAQ and OAQ) 6......................
CO
2
Relative Humidity Sensors 8..........................
Installing Discrete Inputs 8.............................
Compressor Safety 8................................
Humidistat 8......................................
Single Enthalpy (Outdoor Enthalpy) 8..................
Differential Enthalpy 8..............................
Fire Shutdown 9...................................
Filter Status 9......................................
Fan Status 9.......................................
Remote Occupancy 9................................
Communication Wiring-Protocols 10.....................
General 10........................................
R
BACnet
Modbus 11.......................................
Johnson N2 11.....................................
LonWorks 11......................................
Local Access 12....................................
START-UP 13........................................
Additional Installation/Inspection 13.....................
Perfect Humidityt Control Wiring 13..................
Power Exhaust Relay Power 13........................
Service Test 13......................................
Fan Test 13.......................................
High Speed Fan Test 13..............................
Compressor 1 and Compressor 2 Test 13.................
Heat 1 and Heat 2 Test 13............................
Reversing Valve Test 13.............................
Dehumidification Test 14.............................
MS/TP 10................................
Power Exhaust Test 14..............................
Economizer Test 14.................................
Analog Output 2 Test 14.............................
Configuration 14....................................
Setpoint 14.......................................
Unit 14..........................................
Inputs 15.........................................
Service 16........................................
Clockset 17.......................................
USERPW 17......................................
OPERATION 17......................................
Occupancy 17.......................................
Indoor (Supply) Fan 17...............................
Cooling 17.........................................
Supply Fan 18......................................
Economizer 18......................................
Power Exhaust 19....................................
Pre-Occupancy Purge 19..............................
Heating 19.........................................
Indoor Air Quality 19.................................
Dehumidification 19..................................
Demand Limit 20....................................
Unoccupied Free Cooling 20...........................
Optimal Start 20.....................................
Fire Shutdown 20....................................
Compressor Safety 20.................................
Fan Status 20.......................................
Filter Status 20......................................
Door Switch 20......................................
TROUBLESHOOTING 21..............................
General 21.........................................
Thermistor Troubleshooting 21.........................
Software Version 21..................................
Communication LED’s 23.............................
Alarms 25..........................................
Third Party Networking 27.............................
APPENDIX A - USER INTERFACE MENUS 28............
APPENDIX B - THIRD PARTY POINTS LIST 37...........
RTUOPENSTART-UPSHEET 41.......................
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment
can be hazardous due to system pressure and electrical
components. Only trained and qualified service personnel
should install, repair, or service air-conditioning
equipment. Untrained personnel can perform the basic
maintenance functions of replacing filters. Trained service
personnel should perform all other operations.
When working on air-conditioning equipment, observe
precautions in the literature, tags and labels attached to
the unit, and other safety precautions that may apply.
Follow all safety codes. Wear safety glasses and work
gloves.
Follow all safety codes. Wear safety glasses and work
gloves. Have fire extinguisher available. Read these
instructions thoroughly and follow all warnings or
cautions attached to the unit. Consult local building codes
and National Electrical Code (NEC) for special
requirements.
Recognize safety information. This is the safety- alert
TS- 5580- 01
symbol
instructions or manuals, be alert to the potential for
personal injury.
Understand the signal words DANGER, WARNING, and
CAUTION. These words are used with the safety-alert
symbol. DANGER identifies the most serious hazards
which will result in severe personal injury or death.
WARNING signifies a hazard which could result in
personal injury or death. CAUTION is used to identify
unsafe practices which may result in minor personal
injury or product and property damage. NOTE is used to
highlight suggestions which will result in enhanced
installation, reliability, or operation.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Disconnect all power to the unit before performing
maintenance or service. Unit may automatically start
if power is disconnected.
. When you see this symbol on the unit and in
!
WARNING
GENERAL
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 you to select your protocol
(and baud rate) of choice among the four most popular
protocols in use today: BACnet
LonWorks. (See Fig. 1.)
NOTE: Lon Works requires addition of LON option card.
Bryant’s diagnostic display tools such as Field Assistant,
BACview
with the RTU Open controller. Access is available via a
5- pin J12 access port.
6
Handheld or Virtual BACview can be used
R
, Modbus, Johnson N2 and
SENSOR/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 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 between 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 Phoenix
connectors and then reconnect the connectors to the board.
See Fig. 1 and Table 1 for board connections and Fig. 2
for Typical Factory RTU Open wiring.
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.
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury, death and/or equipment damage.
Disconnect electrical power and use lock- out tags
before wiring the RTU Open controller.
2
Input_2 (CO2/RH)
Input_1 (CO2/RH)
+24 VDC
Gnd
Gnd
+24 VDC
Board Power
24 VAC IN
DO-2 (W2)
DO-1 (G)
Gnd
Input_3 (X)
DO-3 (W1)
DO-4 (Y2)
DO-5 (Y1)
Input_5 (SMK)
Input_4 (R)
Input _8 (Enthalpy)
AO-1 (ECON)
Configurable - Input_8
Configurable - Input_5
Configurable - Input_3
Input_9 (Humidistat)
Gnd
24 VAC
(AO-1)
(OAT)
(SAT)
Gnd
Lonworks
Option Card
Port
J4
J12
J13
J22
J17
J2J1
Network Comm
0-10VDC
24 VAC
24 VAC
24 VAC
J3
4-20mA
J5 J5
J11
DO-6 (H)
Dehumidification
DO-7
(Reversing Valve/High Speed Fan)
DO-8
(Power Exhaust)
24 VAC
TS- 5580- 01
Example set for
BACnet MS/TP
and 76.8K baud
(1, 2, and 4 ON)
J15
J20
Protocol Selector SPT (temp input) BACnet, Modbus, or N2
*Remove
both for 0-5V
SPT (common)
SPT (offset input)
J19
(LON connection J15)
J14
Fig. 1 - RTU Open Control Module
C12744
3
Table 1 – RTU Open Inputs and Outputs
POINT NAME
Space Temp / Zone Temp zone_temp AI (10K Thermistor) J20- 1 & 2
Supply Air Temperature sa_temp AI (10K Thermistor) J2- 1 & 2
Outdoor Air T emperature oa_temp AI (10K Thermistor) J2- 3 & 4
Space Temperature Offset Pot stpt_adj_offset AI (100K Potentiometer) J20 - 3 & 4
Safety Chain Feedback safety_status DI (24 VAC) J1- 9
Compressor Safety Status comp_status DI (24 VAC) J1 - 2
Fire Shutdown Status firedown_status DI (24 VAC) J1- 10
Enthalpy Status enthalpy_status DI (24 VAC) J2- 6 & 7
Humidistat Input Status humstat_status DI (24 VAC) J5- 7 & 8
Zone Temperature n/a n/a J13- 1, 2, 3, 4
Indoor Air CO2 iaq AI (4- 20 ma)
Outdoor Air CO2 oaq AI (4 - 20 ma)
Space Relative Humidity space_rh AI (4- 20 ma)
Supply Fan Status* sfan_status DI (24 VAC)
Filter Status* filter_status DI (24 VAC)
Door Contact Input* door_contact_status DI (24 VAC)
Occupancy Contact* occ_contact_status DI (24 VAC)
TS- 5580- 01
Economizer Output econ_output AO (4 - 20ma) J2- 5
SupplyFanRelayState sfan DO Relay (24VAC , 1A) J1- 4
Compressor 1 Relay State comp_1 DO Relay (24VAC , 1A) J1- 8
Compressor 2 Relay State comp_2 DO Relay (24VAC , 1A) J1- 7
Heat Stage 1 Relay State heat_1 DO Relay (24VAC , 1A) J1 - 6
Heat Stage 2 Relay State heat_2 DO Relay (24VAC , 1A) J1 - 5
Power Exhaust Relay State pexh DO Relay (24VAC , 1A) J11- 1 & 3
Perfect Humidity Relay State dehum DO Relay (24VAC, 1A) J11- 7, 8
* These inputs (if installed) take the place of the default input on the speci fic channel
Parallel pins J5- 1 = J2 - 6, J5- 3 = J1 - 10, J5- 5 = J1 - 2 are used for filed installation.
Refer to the input configuration and accessory sections for more detail.
BACnet OBJECT
NAME
DEDICATED INPUTS
CONFIGURABLE INPUTS
TYPE OF I/O
J4- 2 & 3 or J4- 5 & 6
J5- 1 or J5- 3 or J5- 5
OUTPUTS
CONNECTION PIN
NUMBER(S)
Sensors and Accessories
The RTU Open controller is configurable with the
following field-supplied sensors:
NOTE: Supply air temperature sensor (33ZCSENSAT) is
factory-installed.
S Space temperature sensor (33ZCT55SPT, 33ZCT56SPT,
or 33ZCT59SPT)
S Indoor air quality sensor (33ZCSPTCO2- 01,
33ZCSPTCO2LCD- 01, 33ZCT55CO2, 33ZCT56CO2)
required for demand control ventilation.
S Outdoor air quality sensor (33ZCSPTCO2- 01,
33ZCSPTCO2LCD- 01)
aspirator box (C33ZCCASPCO2) required for CO
S CO
2
return duct/outside air applications
S Outdoor air enthalpy switch (33CSENTHSW)
S Return air enthalpy sensor (33CSENTSEN) required for
differential enthalpy control
S Space relative humidity sensor (33ZCSENSRH-02)
S Duct relative humidity (33ZCSENDRH-02)
S Humidistat (--HL--38MG-029)
S Smoke Detectors (CRSMKSEN002A00,
CRSMKKIT002A00)
S Fan and/or Filter Status (CRSTATUS001A00,
CRSTATUS005A00)
User Interfaces
S BACview6Handheld (BV6H)
S Virtual BACview (USB-L or USB-TKIT required)
S Field Assistant (USB-TKIT required)
Install Analog Sensors
Supply Air Sensor (SAT)
The factory supplies the discharge (supply) air sensor with
the unit and is pre- wired. On 04-16 size units, the SAT is
secured to the unit’s supply duct opening. This sensor
must be relocated into the supply duct during unit
installation. On 17-30 size units, the SAT is mounted
through the side of the heat chamber below the fan deck,
2
and does NOT require relocation.
OutdoorAirSensor(OAT)
The OAT is supplied with the economizer option or
accessory. It is wired through the 12-pin plug (PL6) in the
return air section of the unit and is mounted on the
economizer assembly.
Space Temperature Sensor (SPT)
SPT sensors available from Bryant are resistive input
non-communicating (T55, T56, and T59) sensors. These
sensors have a variety of options consisting of: timed
override button, set point adjustment, and a LCD screen.
Space temperature can be also be written to from a building
network or zoning system. However, it is still recommended
that return air duct sensor be installed to allow stand-alone
operation for back-up. Refer to the configuration section for
details on controller configurations associated with space
sensors.
4
TS- 5580- 01
Fig. 2 - Typical Factory Option Wiring
5
C12745
Resistive Non-Communicating Sensor Wiring
For sensor with setpoint adjustment up to 500 ft (152m),
use three-conductor shielded cable 20 gauge wire to
connect the sensor to the controller. For non set point
adjustment (slidebar) or return air duct sensor, an
unshielded, 18 or 20 gauge, two-conductor, twisted pair
cable may be used. Below is the list of the connections of
the SPT to the RTU Open, refer to Fig. 3 and 4 for typical
connections at the sensor.
S J20-1 = temperature sensor input (SEN)
S J20-2 = sensor common
S J20-3 = Setpoint adjustment input (SET)
NOTE: See Fig. 5 for space temperature sensor averaging.
T55/56 Override button will no longer function when sensors
are averaged. Only Sensor 1 T56 STO input can be used.
TS- 5580- 01
2
3
SW1
Cool Warm
45
SEN
61
SET
BLK
(T56)
BRN (GND)
BLU (SPT)
SENSOR WIRING
JUMPER
TERMINALS
AS SHOWN
Fig. 3 - Space Temperature Sensor
Typical Wiring (33ZCT56SPT)
BLK (STO)
BRN (COM)
BLU (SPT)
J20-3
J20-2
J20-1
SENSOR
WIRING
C07131
Rnet Communicating Sensor Wiring
The Rnet bus allows local communication with the RTU
Open, including field supplied communicating sensors.
The Rnet bus can hold up to 6 devices, including up to 2
6
BACview
units, wired in daisy-chain or hybrid
configuration.
6
NOTE: Additional BACview
Refer to the BACview
6
units must be addressed.
installation instructions for for
details on addressing.
For Rnet wiring up to 500ft (152m), use 18 AWG 4
conductor unshielded plenum rated cable. The RTU Open’s
J13-RNET connection has a 4 pin Phoenix connector wired
as described below, Fig. 6 shows sensor Rnet wiring.
S RNET - 1 = Signal ground (GND)
S RNET - 2 = Signal (Rnet+)
S RNET - 3 = Signal (Rnet- )
S RNET - 4 = Power (+12v)
CO2Sensor(s) (IAQ and OAQ)
The indoor air quality (IAQ) and outdoor air quality
2
Sensor
) levels. This
2
(IAQ) sensor
sensor
2
(OAQ) sensors monitor carbon dioxide (CO
information is used to monitor the quality of air in terms
of parts per million (PPM). The same sensor is used for
inside, outside, and duct monitoring, except an aspirator
box is required for outside and duct mounting. The CO
sensor is preset for a range of 0 to 2000 ppm and a linear
mA output of 4 to 20. The rooftop unit may have a factory
installed CO
sensor on the side of the economizer
2
assembly in the return air section of the unit and is
pre-wired and pre-configured at the factory. For field
installed sensors, a field supplied transformer must be
used to power the sensor. Refer to the instructions
supplied with the CO
sensor for electrical requirements
2
and terminal locations. RTU Open configurations must be
changed after adding a CO
for typical CO
sensor wiring.
2
sensor. See below and Fig. 7
2
S J4- 2 or J4- 5 = 4- 20mA signal input
S J4- 3 or J4- 6 = signal common
NOTE: The factory used J4-2&3 for CO
inputs.
Combination Temperature and CO
2
If using a combination temperature and CO
(33ZCT55CO2 or 33ZCT56CO2), refer to the installation
instructions provided with the sensor.
2
OR SET SEN
OPB COM- PWR+
24 VAC
NOTE: Must use a separate isolated transformer.
Fig. 4 - Space Temperature Sensor
Typical Wiring (33ZCT59SPT)
POWER
WIRING
C10291
6
RED
r
BLK
RED
BLK
J20
1
2
J20
1
2
RED
BLK
LEGEND
Factory Wiring
Field Wiring
RED
BLK
RED
BLK
SENSOR 1 SENSOR 2 SENSOR 3 SENSOR 4
RED
BLK
SPACE TEMPERATURE AVERAGING — 4 SENSOR APPLICATION
BLK
BLK
SENSOR 1
RED
SENSOR 4
RED
RED
BLK
SENSOR 2
RED
BLK
SENSOR 5
RED
BLK
RED
BLK
SENSOR 3
RED
BLK
SENSOR 6
RED
BLK
TS- 5580- 01
SENSOR 7
SPACE TEMPERATURE AVERAGING — 9 SENSOR APPLICATION
Fig. 5 - Space Temperature Averaging
C10820
Fig. 6 - Typical Rnet Communication Sensor Wiring
SENSOR 8
SENSOR 9
C07133
To controller
24 Vac Line
-
8 7 6 5 4
+
2 1
24 Vac
or Vdc
Dedicated Transforme
SENSOR LEGEND
1 +24 Vac/Vdc
2 Gnd (-24 Vac/Vdc)
4 -Thermistor
5 +Thermistor
6 4-20 mA
7 SIG COM
8 0-5 Vdc
C12748
Fig. 7 - Indoor/Outdoor Air Quality (CO2)Sensor
(33ZCSPTCO2- 01 or 33ZCSPTCO2LCD- 01)
Typical Wiring Diagram
7
Relative Humidity Sensors (Space or Duct
Mounted)
The accessory space humidity sensor or duct humidity
sensor is used to measure the relative humidity of the air
within the space or return air duct. The RH reading is used
to control the Perfect Humidityt option of the rooftop
unit. For wiring distances up to 500 ft (152m), 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 the
sensor is provided by the RTU Open controller as 24vdc.
Refer to the instructions supplied with the RH sensor for
electrical requirements and terminal locations. RTU Open
configurations must be changed after adding a RH sensor.
See below and Fig. 8 and 9 for typical RH sensor wiring.
S J4- 1 or J4- 4 = 24vdc loop power
S J4- 2 or J4- 5 = 4- 20mA signal input
NOTE: The factory default for dehumidification control
is a normally open humidistat.
Installing Discrete Inputs
TS- 5580- 01
Compressor Safety
The compressor safety input provides the RTU Open with
feedback to when the compressor is not running and
should be. This feedback is usually provided by a
Compressor Lock-Out (CLO) device. Compressor safety
is a dedicated input on the configurable input 3 and tells
the RTU Open when the compressor is locked out. The
normal condition for compressor safety is good operation.
A normally open compressor safety is the factory default
for all units. Follow specific accessory instructions if
installing a CLO device. The CLO should wire into the
unit’s central terminal Board (CTB).
NOTE: Input 3 can also be wired into J-5.
MOUNTING
HOLES
Io
Gnd
Vin
Vo
SW2
123456
ON
a33-9141
Vin - J4 -1 or J4 -4 24Vdc
Io - J4 -2 or J4 -5 4 -20mA output
Fig. 8 - Space Relative Humidity Sensor Typical Wiring
WIRING
OPENING
C07201
Humidistat
The accessory humidistat provides the RTU Open insight
to the relative humidity in the space. The humidistat reads
the RH level in the space and compares it to its setpoint to
operate a dry contact. The humidistat is a dedicated input
on the configurable input 9 and tells the RTU Open when
the RH level is HIGH or LOW. The normal condition for
humidity is LOW. A normally open humidistat is the
factory default control for the Perfect Humidityt option.
To wire in the field:
S J5- 8 = 24 VAC source for dry contact
S J5- 7 = Signal input
Single Enthalpy (Outdoor Enthalpy)
The outdoor enthalpy switch/receiver (33CSENTHSW)
senses temperature and humidity of the air surrounding
the device and calculates the enthalpy when used without
an enthalpy sensor. The relay is energized when enthalpy
is high (above 28 BTU/lb OR dry bulb temperature is
above 75_F) and de-energized when enthalpy is low
(below 27 BTU/lb AND dry bulb temperature is below
74.5_F). The enthalpy input is dedicated to input 8 and
tells the RTU Open when the outside air enthalpy is HIGH
or LOW. The normal condition for the enthalpy input is
HIGH. Enthalpy is configured on input 8 in the factory
when it is added as an option.
NOTE: The enthalpy calculation is done using an
average altitude of 1000 ft above sea level.
For field installation, refer to the enthalpy accessory
instructions. For wiring see below and Fig. 10. The RTU
Open board provides 24vac on one of the two loose grey
wires in the return air section of the rooftop near the
12-pin economizer plug. To determine the correct grey,
measure the voltage on the wires with power applied to
the unit. If 24-vac is sensed, then that is the grey wire that
is connected to the RTU Open board at J2-7. The other is
the signal for input 8, connect it to the LOW Enthalpy
terminal on the enthalpy switch/receiver. Tie into the
12-pin economizer plug on pin 4 or the black wire
connected to the actuator for the enthalpy’s GND
connection. Power can also be provided direct from the
unit transformer and J5 terminal on the RTU Open.
S J2- 7 or J5- 2 = 24 VAC for enthalpy switch power
S J2- 6 or J5- 1 = input signal
Differential Enthalpy
Differential enthalpy control requires both an enthalpy
switch/receiver (33CSENTHSW) and an enthalpy sensor
(33CSENTSEN). The enthalpy sensor must be installed in
the field as the factory can only provide single enthalpy.
The enthalpy sensor must be mounted in the return
airstream and calculates the enthalpy of the indoor air.
The relay is energized when the enthalpy detected by the
return air enthalpy sensor is less than the enthalpy at the
enthalpy switch/receiver. The relay is de-energized when
the enthalpy detected by the return air enthalpy sensor is
greater than the enthalpy at the enthalpy switch/receiver
(differential enthalpy control).
8
J4-1 or J4-4 + 24 VDC Supply Voltage
J4-2 or J4-5 (-)4 to 20 mA Current Loop Output
to RTU Open
Fig. 9 - Duct Relative Humidity Sensor Typical Wiring
To wire return air enthalpy sensor:--MP
Connect the 4-20 mA In terminal on the enthalpy switch/
receiver to the 4-20 mA Out terminal on the return air
enthalpy sensor. Connect the 24-36 VDC Out terminal on
the enthalpy switch/receiver to the 24-36 VDC In terminal
on the return air enthalpy sensor. (See Fig 10.)
Fire Shutdown
The fire shutdown input is provided for unit shutdown in
response to a fire alarm or smoke detector. The fire
shutdown input is dedicated to input 5 and tells the RTU
Open when to shutdown due to smoke detection or fire
alarm system. The normal condition for fire shutdown is
there is no fire alarm. The unit may have factory installed
smoke detector(s); refer to the base unit installation
instructions for details on any adjustments required during
unit installation. Fire shutdown is always factory
configured for a normally open smoke detector.
For field installation of a smoke detector see instructions
for that specific accessory. See below and the
troubleshooting section for wiring at the unit’s Central
Terminal Board (CTB).
S CTB - UNIT SHUTDOWN - 24v OUT = 24 VAC
source
S CTB - UNIT SHUTDOWN - Smoke Alarm = Signal
input to RTU Open
NOTE: Input 5 can also be wired into J5- 3.
Relative Humidity Sensor
(Polarized Male Connector)
4-20mAVAC
VDC
or
GND 0-5V
0-10V
SPAN
ZERO
or
123456
ON
Filter Status
The filter status accessory is a field-installed accessory.
This accessory detects plugged filters. When installing
this accessory, the unit must have a free input (input 3, 5,
8, or 9). One of the dedicated functions (Humidistat, Fire
shutdown, Enthalpy, or Compressor safety) must not be in
use to configure Filter Status. Refer to the configuration
section for details on configuring inputs for specific
functions and state. Refer to Fig. 1 for wire terminations
at J5.
Fan Status
The fan status accessory is a field-installed accessory.
This accessory detects when the indoor fan is moving air.
When installing this accessory, the unit must have a free
input (input 3, 5, 8, or 9). One of the dedicated functions
(Humidistat, Fire shutdown, Enthalpy, or Compressor
safety) must not be in use to configure Fan Status. Refer
to the configuration section for details on configuring
inputs for specific functions and state. Refer to Fig. 1 for
wire terminations at J5.
Remote Occupancy
The remote occupancy accessory is a field-installed
accessory. This accessory provides an input to change the
units occupancy status. When installing this accessory, the
unit must have a free input (input 3, 5, 8, or 9). One of the
dedicated functions (Humidistat, Fire shutdown, Enthalpy,
or Compressor safety) must not be in use to configure
remote occupancy. Refer to the configuration section for
details on configuring inputs for specific functions and
state. Refer to Fig. 1 for wire terminations at J5.
C12756
TS- 5580- 01
9
C10821
TS- 5580- 01
Fig. 10 - Enthalpy Switch and Sensor Wiring
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
on manufacturer. Protocols do not change the function of
a controller; just make the front end user different.
The RTU Open can be set to communicate on four
different protocols: BACnet, Modbus, N2, and LonWorks.
Switch 3 (SW3) on the board is used to set protocol and
baud rate. Switches 1 and 2 (SW1 and SW2) are used to
set the board’s network address. See Fig. 11 and 12 for
protocol switch settings and address switches. The 3rd
party connection to the RTU Open is through plug J19.
See Fig. 13 for wiring. Contact Bryant applications
engineering for more detailed information on protocols,
3rd party wiring, and networking.
NOTE: Power must be cycled after changing the SW1- 3
switch settings.
BACnetRMS/TP
BACnet Master Slave/Token Passing (MS/TP) is used for
communicating BACnet over a sub- network of
BACnet- only controllers. This is the default Bryant
communications protocol. Each RTU Open module acts as
an MS/TP Master. The speed of an MS/TP network can
range from 9600 to 76.8K baud. Physical Addresses can
be set from 01 to 99.
10
SW3 Protocol Selection
PROTOCOL DS8 DS7 DS6 DS5 DS4 DS3 DS2 DS1
BACnet MS/TP
(Master)
Modbus
(Slave)
N2
(Slave)
LonWorks Unused ON ON OFF ON OFF OFF ON
NOTE:
DS = Dip Switch
BACnet MS/TP SW3 example shown
BAUD RATE DS2 DS1
9600 OFF OFF
19,200 ON OFF
38,400 OFF ON
76,800 ON ON
Unused OFF OFF OFF ON OFF Select Baud Select Baud
Unused OFF OFF ON ON OFF Select Baud Select Baud
Unused OFF OFF OFF ON ON OFF OFF
Baud Rate Selections
Fig. 11 - RTU Open SW3 Dip Switch Settings
Fig. 12 - RTU Open Address Switches
C10815
C07166
TS- 5580- 01
Modbus
The RTU Open module can speak the Modicon Modbus
RTU Protocol as described in the Modicon Modbus
Protocol Reference Guide, PI- -MBUS- -300 Rev. J. The
speed of a Modbus network can range from 9600 to 76.8K
baud. Physical Addresses can be set from 01 to 99.
Johnson N2
N2 is not a standard protocol, but one that was created by
Johnson Controls, Inc. that has been made open and
available to the public. The speed of N2 network is
limited to only 9600 baud. Physical Addresses can be set
from 01 to 99.
LonWorks
LonWorks is an open protocol that requires the use of
Echelon’s Neuron microprocessor to encode and decode
the LonWorks packets. In order to reduce the cost of
adding that hardware on every module, a separate
LonWorks Option Card (LON- OC) was designed to
connect to the RTU Open.
This accessory card is needed for LonWorks and has to be
ordered and connected using the ribbon cable to plug J15.
The RTU Open’s baud rate must be set to 38.4k to
communicate with the LON-OC. The address switches
(SW1 & SW2) are not used with LonWorks.
Fig. 13 - Network Wiring
C10816
11
LON OC Rev.4
COMM
OPTION
Network
Net
Connector
Local Access
TS- 5580- 01
BACview6Handheld
6
The BACview
connect to the RTU Open to access the control
information, read sensor values, and test the RTU. (See
Fig. 15.) This is an accessory interface that does not come
with the RTU Open controller. You connect the
BACview
6
of the communicating space sensor’s access port. There
are 2 password protected levels in the display (User and
Admin). The user password is defaulted to 0000, but can
be changed. The Admin password is 1111 and cannot be
changed. There is a 10 minute auto logout if a screen is
left idle. See Appendix A for navigation and screen
content.
is a keypad/display interface used to
to the RTU Open’s J12 local access port or one
1 2
Fig. 14 - LON- OC and LON Network Wiring
J15
C12750
Virtual BACview
Virtual BACview is a freeware computer program that
functions as the BACview
interface (USB- L) is required to connect a computer to
the RTU Open board. The link cable connects a USB port
to the J12 local access port. This program functions and
operates identical to the handheld.
Field Assistant
Field Assistant is a computer program included with the
purchase of the USB Link Tech Kit (USB-TKIT). This is a
field Tech Tool to set-up, service, or download the RTU
Open controller. The link cable connects a USB port to
the J12 local access port. The menu structure is similar to
the BACview.
6
Handheld. The USB Link
Access Port
P1 P1
J12
Cable
P5 P5
Fig. 15 - BACview6Handheld Connections
12
BACview
Protocol Selector
RTU Open
6
Local Access Cable
C12749
START- UP
IMPORTANT: Follow the base unit’s start-up sequence
documented in its specific instructions. Use the base unit’s
start-up check list when performing the start-up. At the
end of this manual there is an additional RTU Open
Start-up Sheet to be completed and included with the base
unit check list.
Besides the base unit start-up, there are a few steps to take
to properly start-up the controls. RTU Open’s Service Test
function should be used to assist in the base unit start-up
and also allows verification of output operation.
Controller configuration is also part of start-up. This is
especially important when field accessories have been
added to the unit. The factory pre-configures options
installed at the factory. There may also be additional
installation steps or inspection required during the start-up
process.
Additional Installation/Inspection
Inspect the field installed accessories for proper
installation, making note of which ones do or do not
require configuration changes. Inspect the RTU Open’s
Alarms for initial insight to any potential issues. See
troubleshooting section for alarms. Inspect the SAT sensor
for relocation as intended during installation. Inspect
special wiring as directed below.
Perfect Humidityt Control Wiring
In units equipped with the optional Perfect Humidity
option there are 2 loose wires (one pink and one
pink/black) in the control box used to control the
dehumidification function of the unit. These wires are
meant to be ties to a space humidistat or thermidistat on
an electromechanical unit. On RTU Open equipped units
these wires must be connected to J11-7 & 8 to allow the
Open board to operate the dehumidification function or
the unit. Disconnect the J11 Phoenix style connector form
the board and use the plug screws to secure the pink/black
wire in pin 7 and and the pink wire in pin 8, reconnect the
plug to the board at J11.
Power Exhaust Relay Power
The relay used by the RTU Open board to control power
exhaust is a dry contact which means it does not have
24vac. This 24vac must be connected to the relay to allow
it operate the power exhaust relay in the PE accessory. A
24vac source should be provided to the J11-2 pin on the
RTU Open. This can be provided by the unit’s transformer
from various sources. The “R” terminal on the unit’s
central terminal board (CTB) is a logical source.
Service Test
The Service Test function can be used to verify proper
operation of compressors, heating stages, indoor fan,
power exhaust fans, economizer, and dehumidification.
Use of Service Test is recommended at initial system start
up and during troubleshooting. See Appendix A for
Service Test Mode table.
Service Test mode has the following changes from normal
operation:
S Outdoor air temperature limits for cooling circuits,
economizer, and heating are ignored.
S Normal compressor time guards and other staging
delays are ignored.
S The status of Alarms (except Fire and Safety chain) is
ignored, but all alerts and alarms are still broadcasted
on the network.
Service Test can be turned ON/OFF at the unit display or
from the network. Once turned ON, other entries may be
made with the display or through the network. To turn
Service Test on, change the value of Test Mode to ON, to
turn Service Test off, change the value of Test Mode to
OFF.
NOTE: Service Test mode is password protected when
accessing from the display. Depending on the unit model,
factory-installed options, and field-installed accessories,
some of the Service Test functions may not apply.
Fan Test
This point allows the board’s fan output to be manually
turned On (Enable) and Off (Disable). Other test points
that require the fan for operation will automatically turn
the fan on and this point will still show “Disable.” Fan test
can operate simultaneously with other Service Test Points.
High Speed Fan Test
Use the High Speed Fan Test to activate and deactivate
the Supply Fan (BO-1) output.
NOTE: This output is only applicable if Fan Control is
set to Two Speed and Unit Type is not equal to HP O/B
Ctrl.
Compressor 1 and Compressor 2 Test
The compressor test points are used to change output
status for the individual compressors. Compressor starts
are not staggered. The fan and heating service test outputs
are reset to “Disable” for the compressor service tests.
The Indoor fan and outdoor fans are controlled normally
to maintain proper unit operation. All normal cooling
alarms and alerts are functional.
NOTE: Compressor 1 is always operated with Compressor
2 due to outdoor fan control on Compressor 1. Always test
Compressor 1 first, and leave it on to test Compressor 2.
Heat 1 and Heat 2 Test
The heat test points are used to change output status for
the individual heat stages, gas or electric. The fans and
cooling service test outputs are reset to “Disable” for the
heat service tests. Indoor and outdoor fans are controlled
normally to maintain proper unit operation. All normal
heating alarms and alerts are functional.
Reversing Valve Test
This test point activates the DO7 relay at J11. These
rooftop units do not use reversing valve control for heat
pumps, therefore this test is not used.
TS- 5580- 01
13
Dehumidification Test
For units with the factory Reheat option, the
dehumidification relay is used to change the output status
to operate the circuits in different Reheat modes.
Dehumidification relay on by itself puts all circuits
running in Hot Gas Reheat dehumidification mode;
dehumidification relay on and the cooling test
(compressor test relays) on puts unit and or individual
circuits in subcooling dehumidification mode. The fans
and heating service test outputs are reset to “Disable” for
the dehumidification service test. Indoor and outdoor fans
are controlled normally to maintain proper unit operation.
All normal cooling/dehum alarms and alerts are
functional.
Power Exhaust Test
This point allows the board’s power exhaust (PE) output
to be manually turned On (Enable) and Off (Disable).
Power Exhaust test can operate simultaneously with other
Service Test Points.
Economizer Test
TS- 5580- 01
This point allows the board’s economizer output to be
manually controlled from 0 to 100 % Open. Economizer
test can operate simultaneously with other Service Test
Points.
Analog Output 2 Test
This test point activates the AO2 0-10vdc analog output at
J22. These rooftops do not use this output, therefore this
test is not used.
NOTE: Service Test Mode does not timeout. Be sure to
turn off test mode or cycle power to the RTU to return to
normal operation.
Configuration
The RTU Open controller’s configuration points effect the
unit’s inputs and operation. Review and understand the
meaning and purpose of each configuration point before
changing it from the factory default value. Use the RTU
Open Start-up Sheet during configuration; fill in changed
values if changed from factory default. There are three
main configurations menus: SETPOINT, UNIT, and
SERVICE. Each configuration point is described below
under its according menu. See Appendix A for BACview
menu structure.
Setpoint
Occupied Heating Setpoint - The heating setpoint the
controller maintains during the occupied period.
Range = 40-90_F Default = 70_F
Occupied Cooling Setpoint – The cooling setpoint the
controller maintains during the occupied period.
Range = 55-99_F Default = 76_F
Unoccupied Heating Setpoint – The heating setpoint the
controller maintains during the unoccupied period.
Range = 40-90_F Default = 55_F
Unoccupied Cooling Setpoint – The cooling setpoint the
controller maintains during the unoccupied period.
Range = 45-99_F Default = 90_F
Effective Heating Setpoint – The current setpoint value
heating operation will control to.
Range = 0-120_F
Effective Cooling Setpoint – The current setpoint value
cooling operation will control to.
Range = 0-120_F
Optimal Start - The earliest time prior to occupancy, at
which the Optimal Start function may begin to adjust the
effective setpoints. Setting this to 0 will disable optimal
start.
Range = 0-4 hours Default = 4 hours
Occ Relative Humidity Setpoint – The space RH setpoint
the controller maintains during the occupied period.
Range = 0 to the Unocc RH setpoint
Default 60%
Unocc Relative Humidity Setpoint – The space RH
setpoint the controller will maintain during the
unoccupied period.
Range = 30-100% Default = 95%
DCV Max Ctrl Setpoint – The difference between indoor
and outdoor CO
ventilation damper position.
Range = 0-9999ppm Default = 650ppm
Power Exhaust Setpoint – When the economizer damper
position opens above this point the power exhaust
operation will begin. When the damper position falls
below this point and 5% lower the power exhaust will
shutdown.
Range = 20-90% Default = 50%
NOTE: This point is only used when Continuous
Occupied Exhaust = NO
level which results in maximum
2
Unit
Fan Mode – Sets the operation of the indoor fan when not
in cooling or heating mode. Refer to fan operation for
details on each operation.
Range = Auto, Continuous, or Always On
Default = Continuous
Power Fail Restart Delay - Sets how long the controller
delays normal operation after the power is restored.
Typically used to prevent excessive demand when
recovering from a power failure
Range = 0-30 sec Default = 5 sec
Fan Off Delay – Time delay in which the fan will
continue run after being commanded off.
Range = 10-300sec Default = 90sec
Minimum Cooling SAT – The supply air temperature
must remain above this value to allow cooling with the
economizer and/or compressors. There is 5_Fplusand
minus deadband to this point. If the SAT falls below this
value during cooling a compressor stage will be removed
and/or the economizer will return to minimum position.
Range = 45-75_F Default = 50_F
Maximum Heating SAT – The supply air temperature must
remain below this value to allow heating. There is 5_Fplus
and minus deadband to this point. If the SAT falls below this
value during heating the heat stages will begin to decrease
until the SAT has dropped below this value.
Range = 85-150_F Default = 120_F
Vent Dmpr Pos / DCV Min Pos – Minimum damper
position for ventilation during the occupied period
Range = 0-100% open Default = 20% open
14
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