
MNB-300
Dimensions shown
are in inches (mm).
2
(50.8)
4
(101.6)
7 (177.8)
2
(50.8)
3-1/2 (88.9)
MicroNet BACnet
Unitary Controller
Installation Instructions
Application
The I/A Series® MicroNet™
BACnet
an interoperable controller
with native BACnet, IP, and
MS/TP communications
support. The controller
features Sensor Link (S-Link)
support, LED status and
output indication, screw
terminal blocks, as well as a
panel mount sub-base with removable electronics module.
When programmed using WorkPlace Tech Tool, the Unitary
Controller provides a wide range of control strategies for
packaged rooftop, heat pump, fan coil, unit ventilator, and
similar applications.
®
Unitary Controller is
Model Chart
Model
Number
MNB‑300 6 3 6
Inputs and Outputs
UI UO DO (Triacs)
Installation
Inspection
Inspect carton for damage. If damaged, notify carrier
immediately. Inspect controllers for damage upon receipt.
Precautions
When installing the MNB-300 controller, be sure to
follow the guidelines outlined in “Precautions” on
page 4.
Location
The MNB-300 controller is suitable for indoor use only. The
mounting location must clear the maximum dimensions of the
controller case and allow sufcient clearance for access to
wiring terminals.
Caution:
• Avoid locations where excessive moisture, corrosive
fumes, vibration, or explosive vapors are present.
• Avoid electrical noise interference. Do not install near
large contactors, electrical machinery, or welding
equipment.
• Locate where ambient temperatures do not exceed
140°F (60°C) or fall below -40°F (-40°C) and relative
humidity does not exceed 85% or fall below 5%, noncondensing.
Dimensions
Mounting dimensions for the MNB-300 controller are shown
in Figure-1. Refer to Figure-3 for mounting dimensions for
optional enclosure MNB-300-ENC.
Requirements
• Installer must be a qualied technician
The following items are not provided.
• Job wiring diagrams
• Tools:
– Drill and bits for mounting screws
– Screw drivers
– Nut drivers
– Digital Volt-ohm meter (DVM)
– Static protection wrist strap
• MNB-300-ENC enclosure for wall-mounting (optional)
• Class 2 power transformer supplying a nominal 12 VA at
24 Vac plus DO load; in European Community, transformer
must conform to EN 60742
• Four #10 pan head screws for wall-mounting
• Four #10 pan head screws for panel-mounting
• If needed, end-of-line termination resistor, 120 W ±5%,
part number 40-1758
Schneider Electric
F-27345 -4 May 2014
Figure-1 Mounting Dimensions.

Input
Board
Controller
Base Plate
Mounting
Hole
(1 of 4)
Base of Optional
Enclosure
MNB-300-ENC
Threaded Studs for
Mounting Controller
(1 of 4)
(part of enclosure base)
#10 Pan Head
Screw (1 of 4)
(not supplied)
#10 Pan Head
Screw (1 of 4)
(not supplied)
Mounting Hole
(1 of 4)
Thumb Screws
(1 of 4)
Output
Board
7 Tighten the four thumb screws
CW to secure the input and output
boards in place.
6 Press on the aluminum tabs to slide the input and output boards
into the controller, making sure the mating connectors engage fully.
Note: The connectors are properly
engaged when the gap between
the controller and the input and
output boards is even and minimal
from top to bottom.
5 Position the controller onto the
base plate.
4 Be sure the input and output
boards are spread apart as far as
possible. If needed, loosen the four
thumb screws by turning them
CCW and then reposition the
boards.
1 Select a mounting location. The MNB-300 may be panel-
mounted or, optionally, enclosure-mounted. To panelmount the MNB-300, go to Step 2. To mount the MNB-300
inside optional Enclosure MNB-300-ENC, go to Step 3.
Note: The MNB-300 may be mounted in any orientation.
2 To mount the MNB-300 to a panel, proceed as follows:
a. Holding the controller's base plate in position, mark
the locations of the four mounting holes on the panel
.
b. Set the base plate aside and drill the marked
mounting holes, using a drill bit sized to the mounting
screws.
c.
Secure the base plate to the panel, using four #10
screws (not supplied).
d.
Continue at Step 4.
3 Optional To mount the MNB-300 inside Enclosure
MNB-300-ENC, proceed as follows:
a. Separate the enclosure cover from the enclosure
base.
b. Holding the enclosure's base in position on the
wall, mark the locations of the four mounting holes.
c. Set the enclosure base aside and drill the marked
mounting holes, using a drill bit sized to the
mounting screws
.
d.
Secure the enclosure base to the wall, using four
#10 screws (not supplied).
e.
Mount the controller's base plate onto the four
threaded studs on the enclosure's base. Secure
the base plate, using four #6-32 nuts (provided)
.
f.
Continue at Step 4.
Aluminum
Tab (1 of 2)
Connectors
Tab
Slot
Mounting
2
Mount the controller to the wall according to Figure-2.
Warning: Electrical shock hazard! Disconnect power before installing or removing the cover.
Schneider Electric
F-27345 -4 May 2014
Figure-2 MNB-300 Mounting.

Dimensions shown
are in inches (mm).
10-1/2 (267)
2-1/4
(57)
6-1/8
(156)
3
(76)
9-1/4 (235)
Enclosure
Cover
Enclosure
Base
I/A Series
®
1 1
1
1 Outside dimensions of the enclosure cover.
Optional
Enclosure
3
Optionally, the MNB-300 may be mounted inside an enclosure. Refer to Figure-3 for mounting
dimensions for enclosure MNB-300-ENC.
Figure-3 Enclosure MNB-300-ENC Mounting Dimensions.
DIP Switch
Each MicroNet BACnet controller is equipped with a DIP switch for setting the controller’s MS/
TP network address. Once the address is set, the network is properly wired, and all routers are
congured, WorkPlace Tech Tool (must be version 5.0 or greater) and other Schneider Electric
tools will be able to “see” and work with all the networked BACnet devices. For guidance in
assigning a DIP switch setting that will optimize system performance, refer to the WorkPlace
Tech Tool 5.0 Engineering Guide Supplement, F-27356.
Other BACnet Devices
The UNC and other BACnet devices on the network can work with the MicroNet BACnet
controller once they are assigned unique identiers and names. MicroNet BACnet controllers
are congured in this way through the Commissioning Tool.
Note: The logical addressing of devices (i.e. the assignment of unique identiers and names) is
not a prerequisite for using Invensys network management tools. It is, however, a prerequisite
for using the UNC and third-party BACnet devices with MicroNet BACnet controllers.
EOL Termination
The MNB-300 is equipped with a jumper-selectable end-of-line (EOL) termination resistor. The
default position for the EOL jumper is “EOL termination not present.” If the controller is at the
end-of-line, set termination according to the MicroNet BACnet Wiring and Networking Practices
Guide, F-27360.
Note: If another device is at the end-of-line on the MS/TP trunk, use an end-of-line termination
resistor, 120 W ±5%, part number 40-1758.
Schneider Electric
F-27345 -4 May 2014

Installation
Completion
Finish installing the MNB‑300 controller by performing the wiring and network conguration
tasks outlined in the MicroNet BACnet Wiring and Networking Practices Guide, F-27360.
Information covered in this Guide include:
• Communications wiring • Logical addressing of devices
– MicroNet BACnet wiring
– Sensor Link (S-Link) wiring
• Conguration of routers
• Communications hardware checkout
• Input/Output wiring • Troubleshooting
• Power supply wiring • A list of related documentation
• Mechanical hardware checkout
Precautions
General
Warning: Electrical shock hazard! Disconnect power before installing or removing the cover.
• Follow Static Precautions (below) when installing this equipment.
• Use copper conductors that are suitable for 167°F (75°C).
• Make all connections according to electrical wiring diagram, national and local electrical
codes.
Static Precautions
Static charges damage electronic components. The microprocessor and associated circuitry
are extremely sensitive to static discharge. Use the following precautions when installing,
servicing, or operating the system.
• Work in a static-free area.
• Discharge static electricity by touching a known, securely grounded object.
• Use a wrist strap connected to earth ground when handling the controller’s printed circuit
board.
Federal Communications Commission (FCC)
This equipment has been tested and found to comply with the limits for a Class A digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference when the equipment is operated in a commercial
environment. This equipment generates, uses, and can radiate radio frequency energy, and, if
not installed and used in accordance with the instruction manual, may cause harmful
interference to radio communications. Operation of this equipment in a resdential area is likely
to cause harmful interference, in which case the user will be required to correct the interference
at his own expense.
Canadian Department of Communications (DOC)
This Class A digital apparatus meets all requirements of the Canadian Interference-Causing
Equipment Regulations.
European Community Directives
This equipment meets all requirements of European Community Directives for Low Voltage
(72/23/EEC), General Safety (92/59/EEC), and Electromagnetic Compatibility (89/336/EEC).
Schneider Electric
F-27345 -4 May 2014
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