LYNX BACnet PROGRAMMABLE, VAV/UNITARY CONTROLLERS – PRODUCT DATA
EN0Z-0959GE51
R0615
7
NOTE 3:
A jumper should be installed between 24 VAC
COM (term. 2) and EGND (term. 3). Further,
EGND (term. 3) should be connected to a verified
earth ground, and kept as short as possible.
NOTE 4:
Do not connect the universal input COM terminals,
analog output COM terminals or the digital
input/output COM terminals to earth ground. See
Fig. 13 through Fig. 18 for wiring examples.
The 24 Vac power from an energy limited Class II power
source must be provided to the controller. To conform to
Class II restrictions (U.S., only), the transformer must not be
larger than 100 VA.
Fig. 9 depicts a single controller using one transformer.
IMPORTANT
Power must be OFF prior to connecting to or removing
connections from the 24 Vac power (24 Vac/24 Vac
COM), earth ground (EGND), and 20 Vdc power (20
Vdc) terminals.
IMPORTANT
Use the heaviest gauge wire available, up to 2.0 mm
2
,
with a min. of 1.0 mm
2
, for all power and earth ground
wiring.
Screw-type terminal blocks are designed to accept up
to one 2.0 mm
2
conductor or up to two 1.0 mm
2
con-
ductors. More than two wires that are 2.0 mm
2
can be
connected with a wire nut. Include a pigtail with this
wire group and attach the pigtail to the terminal block.
IMPORTANT
Connect terminal 2, (the 24 Vac common [24 VAC
COM] terminal) to earth ground (see Fig. 9).
NOTE:
Unswitched 24 Vac power wiring can be run in the
same conduit as the BACnet MS/TP cable.
1 2 3 4 5 6 7 8
9
OUTPUT
DEVICE POWER
TRANSFORMER
LINE VOLTAGE
> 150 VAC
COM
24 VAC
EARTH GROUND
(TERMINAL 3)
EARTH
GROUND
WHEN CONNECTING POWER TO THE LYNX BACnet
CONTROLLER, CONNECT THE COM LEG OF THE VAC
SECONDARY CIRCUIT TO A KNOWN EARTH GROUND.
CONNECT POWER TO
TERMINALS 1 AND 2.
Fig. 9. Power wiring details for one LYNX controller per
transformer
More than one controller can be powered by a single trans-
former. Fig. 10 shows power wiring details for multiple con-
trollers.
NOTE:
Controller configurations are not necessarily limited
to three devices, but the total power draw,
including accessories, cannot exceed 100 VA
when powered by the same transformer (U.S.,
only). For power wiring recommendations, see
section “Power” on page 6.
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
9
9
9
OUTPUT DEVICE POWER
TRANSFORMER
120/240 VAC
COM
24 VAC
EARTH GROUND
(TERMINAL 3)
EARTH GROUND
(TERMINAL 3)
EARTH GROUND
(TERMINAL 3)
EARTH
GROUND
WHEN CONNECTING POWER TO THE LYNX BACnet
CONTROLLER, CONNECT THE COM LEG OF THE VAC
SECONDARY CIRCUIT TO A KNOWN EARTH GROUND.
CONNECT POWER TO
TERMINALS 1 AND 2.
CONNECT POWER TO
TERMINALS 1 AND 2.
CONNECT POWER TO
TERMINALS 1 AND 2.
Fig. 10. Power wiring details for two or more LYNX
controllers per transformer
Communications
Each LYNX controller uses a BACnet MS/TP communications
port. The controller’s data is presented to other controllers
over a twisted-pair MS/TP network, which uses the EIA-485
signaling standard capable of the following baud rates: 9.6,
19.2, 38.4, 76.8 or 115.2 kilobits per sec (configured at global
controller). The LYNX controllers are master devices on the
MS/TP network. Each LYNX controller uses a high-quality
EIA-485 transceiver and exerts ¼ unit load on the MS/TP
network.
Cabling should be selected that meets or exceeds the
BACnet Standard which specifies the following: An MS/TP
EIA-485 network shall use shielded, twisted-pair cable with
characteristic impedance of 100…130
Ω
. Distributed
capacitance between conductors shall be less than 100 pF
per meter. Distributed capacitance between conductors and
shield shall be less that 200 pF per meter. Foil or braided
shields are acceptable. The Honeywell tested and
recommended MS/TP cable is Honeywell Cable 3322 (18
AWG, 1-Pair, Shielded, Plenum cable), alternatively
Honeywell Cable 3251 (22 AWG, 1-Pair, Shielded, Plenum
cable) is available and meets the BACnet Standard require-
ments (www.honeywellcable.com).
The max. BACnet MS/TP network Bus segment length is
1,219 m using recommended wire. Repeaters must be used
when making runs longer than 1,219 m. A max. of three
repeaters can be used between any two devices.
Setting the MS/TP MAC Address
The MS/TP MAC address for each device must be set to a
unique value in the range of 0-127 on an MS/TP network
segment (address 0, 1, 2, & 3 should be avoided as they are
commonly used for the router, diagnostic tools, and as spare
addresses). DIP switches on the LYNX controller are used to
set the controller's MAC address.
To set the MS/TP MAC address of a LYNX controller:
