Lindab UltraLink FTMU Manual

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Technical information
LindabUltraLink®Monitor
FTMU

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Lindab reserves the right to make changes without prior notice
2021-11-02
UltraLink®Monitor FTMU
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Introduction
UltraLink®FTMU is a highly accurate flow monitor without any obstacles in the airstream that creates pressure drop. It mea-
sures the flow with an angled ultrasonic beam which can be calculated and compensated to a very high accuracy over the
whole flow range. The method is very stable over time due to that it is not sensitive to dirt and the design minimizes the dust
accumulation on the flow sensors.
An increased focus on energy saving has led to ventilation systems requiring low minimum flows. The low flows are a pro-
blem since they are very difficult to measure, which makes it difficult to control the ventilation system.
The new technology of UltraLink®makes it possible to measure lower air flows compared to today’s products while maintai-
ning measurement accuracy. This offers great advantages for the user in terms of comfort and savings in energy consump-
tion, which is of great interest.
Content
Introduction .................................................................................................... 2
Overview (Application, Design, Display unit) .................................................3
Mounting ........................................................................................................4
Electrical installation ......................................................................................7
Commissioning ............................................................................................ 11
Mobile app .............................................................................................. 11
Ultra BT™ Room Control System (Installation of wireless sensors) ...... 11
Display .................................................................................................... 12
Parameter structure................................................................................ 12
Status light.............................................................................................. 12
Connecting flow measurement for installation close to disturbance ..... 13
ID-numbers............................................................................................. 13
PIN code ................................................................................................. 13
Maintenance ........................................................................................... 13
Configuration menu structure................................................................. 13
Digital communication settings.................................................................... 14
Analog communication settings .................................................................. 14
Troubleshooting ........................................................................................... 15
Technical data .............................................................................................. 16
Appendix A – Modbus register .................................................................... 17
© 11.2021 Lindab Ventilation. All forms of reproduction without written permission are forbidden. is the registered trademark of Lindab AB.
Lindab's products, systems, product and product group designations are protected by intellectual property rights (IPR).

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UltraLink®Monitor FTMU
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2021-11-02
Overview
Application
The FTMU is suitable for measuring air flow and tempe-
rature. Communication is established via analog or digital
signal using Modbus.
Design
The FTMU consists of a sensor body with Lindab Safe
gaskets.
Two flow sensors are mounted on the sensor body and
connected to a display unit. The display unit is mounted
on top of a shelf on the sensor body.
Note! The flow sensors are placed at a fixed distance
to each other and they shall never be removed and
not used as handles when turning the sensor body.
Display unit
QR code
Status light
Bluetooth®
Display parameters
Air flow direction
Mode button
CE-mark
IP classification
Display unit
Transducer
Sensor body

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Mounting
Please note:
• The transducers must never be removed!
• Do not use the transducers as handles when you mount the
FTMU since this may cause damage!
Transducers
• Make sure the airflow arrow is pointing in the direction of the
airflow.
Airflow direction arrow
• Rotate the senor body to the correct position according to
the chapter “Planning” on the next page.
• Position the display so it is visible from a suitable direction.
By loosening the screw of the steel strip, the display unit can
be rotated.
• Mount the FTMU into the air duct system according to the
mounting instructions for Lindab Safe.
• Never use a FTMU on the outlet side of a duct fan. (Place it
on the inlet side or in worst case use a flow conditioner if it
must be placed on the outlet side.)
Duct fan
• Note the ID-number of the FTMU. The ID is the three last
numbers of the serial number and can be found:
- on the label of the box it was delivered in
- on the label on the FTMU itself
- in the display after pressing the “MODE” button
- in the App when the product is turned on
Controller FTCU Ø125
Serial no. 132600052
UltraLink
Lindab®

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Planning
The longer distance to disturbance, i.e. the longer straight duct before the FTMU, the higher the measurement accuracy
will be. However this is not the only factor which affects the accuracy of the measurement. The rotation of the FTMU
and hence the positioning of the first flow sensor has an impact on the uncertainty of the measurement. It is not
recommended to mount the FTMU so that the first flow sensor (*) is placed on an outer radius of a fitting.
For example: in the case of the bend in the table below, by rotating the FTMU to position the first flow sensor according
to the first picture (with the first flow sensor on the inner radius of the bend), the FTMU can be placed at the distance
of two duct diameters from the disturbance to achieve 5 % uncertainty. Positioning the FTMU according to the second
picture (with the first sensor on the outer radius of the bend), the FTMU must be mounted five duct diameters from the
disturbance to achieve the same level of uncertainty.
Other obstructions in the duct system such as axial fans, silencer baffels or cleaning hatches etc. are not allowed before
the UltraLink (in the direction of the flow). If a cleaning hatch is required, it must be placed after the UltraLink (in the direc-
tion of the flow). The reason is that these cause turbulences, which can result in errors in flow measurements.
Disturbance * Placement of first flow sensor
Measurement uncertainty
± % or X l/s depending wich
is the greatest of percentage
or the absolute value for the
specific product size, see
table on page 16.
a
2-4·Ød >4-5·Ød >5·Ød
Bend
a
Ød *
Inner radius
(Best position)
5 5 5
Bend
a
Ød
*
Outer radius
(Not recommended)
20 10 5
Bend
a
Ød
*
a
Ød *
Side 10 5 5

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Disturbance * Placement of first flow sensor
Measurement uncertainty
± % or X l/s depending wich
is the greatest of percentage
or the absolute value for the
specific product size, see
table on page 16.
a
2-4·Ød >4-5·Ød >5·Ød
Reducer
a
Ød
*
Duct diameter
decrease 5 5 5
Reducer
a
Ød
*
Duct diameter increase 10 5 5
T-piece
a
Ød
*
Inner radius
(Best position)
10 5 5
T-piece a
Ød
*
Outer radius
(Not recommended)
20 10 5
T-piece
a
Ød
*
Side 10 5 5
a
Ød
*

7
24V +B
-A SH
GND
GND
GND
AO1
AO2
AIN MO1
MO2
1234 5 678910 11 12
SCL SDA GND 3V3
1615
14
13
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Electrical installation
Please note:
• You must under no circumstances make any holes or connect anything with screws to
the body of the FTMU.
• In case electrical installation equipment such as a junction box is needed for installation,
the FTES is a Lindab accessory which can be mounted on the FTMU without causing
damage to the FTMU.
• Never remove the blue electronics box.
• Never remove the transducers.
Use the premounted cable >>
• Connect power and communication cables to the
premounted cable.
• Check the label on cable for reference to cable
colours.
• It is important that the cable is as short as pos-
sible for optimal Modbus communication.
For cable connections there is two options, use the
premounted cable or connect directly in the
PCB (option A and B):
Connect directly on PCB >>
• To access the terminals on the circuit board,
remove the lid by pushing the two heels on the
side of the blue box.
• To be able to connect cords to the terminal board
the rubber cable grommet on the backside of the
display unit must be punctured, preferably using
an awl or something pointy to ensure tightness to
the environment. Do not remove the blue box to
do this!
• When the cables have been connected they must
be strain relieved. The cables can be attached
to the shelf by using cable ties that are attached
around cut outs in the shelf.
Option A
Option B

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24V +B
-A SH
GND
GND
GND
AO1
AO2
AIN MO1
MO2
1234 5 678910 11 12
SCL SDA GND 3V3
1615
14
13
24V AC/DC {G+
G-
Modbus +B
-A
GND
Analog
signals {AO1
AO2
AIN
{
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Option B: Circuit board screw terminals
Connections are made in the terminal board which can be accessed when the lid of the display unit is removed. In the
back of the lid there is a picture with a list of the terminals.
1. 24V, power supply (AC G, DC +) *
2. GND, power supply (AC G0, DC -) *
3. +B, connection for Modbus via RS485
4. -A, connection for Modbus via RS485
5. SH, shield
6. GND, ground (system neutral)
7. AO1, analog output
8. AO2, analog output
9. AIN, (not used in this version)
10. MO1, (not used in this version)
11. MO2, (not used in this version)
12. GND, ground (system neutral)
13. SCL, not used
14. SDA, not used
15. GND, ground (system neutral)
16. 3V3, not used (in case of biasing)
*) When using AC terminal 1 (G) should have system potential and terminal 2 (G0) should be system neutral.
Recommendations for wiring
Function Cable type
24 V Supply 2-wire, thickness depending on length and load, max. 1,5 mm²
RS485 Modbus communication 2-wire shielded twisted pair, min. 0,1 mm² (LIYCY cable)
Using other cables for Modbus signals may result in communication problems.
Analog connection
When connecting the FTMU
using analog signals, it is impor-
tant to connect the analog out
signals on the FTMU (AO1, AO2)
to the analog in terminals on the
RTU and the analog in signal
(AIN) is connected to the analog
out terminal on the RTU. Also
make sure to connect the cables
to the same analog ground.
Option A: Connect to premounted cable
Connect the premounted cable in a junction box near the FTMU. Con-
nect power and signal cables in the junction box according to the color
scheme on the lable on the premounted cable, see picture to the right.
When connecting Modbus signal wires, the length of the premounted
cable needs to be as short as possible, since these have a negative
effect on signal quality.
In this case, place junction box as close to the FTMU as possible, then
cut the premounted where it is as short as possible for installation.
Connection of
UltraLink
Note! All cables that are
not connected must be
insulated.
24V Red
GND White
+B Yellow
-A Brown
GND Grey
AO1 Green
AO2 Blue
AIN Pink

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UltraLink®Monitor FTMU
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Digital connection (Modbus)
Connect A on the RTU to -A on the display unit and B to +B. When connecting more than one FTMU in series it is
important to keep connecting -A to -A and +B to +B since crossing them will stop Modbus from working. It is recom-
mended to use RS485 cables with twisted pairs and shield, do not supply power in the same cable unless the cable
is produced for that purpose. When connecting signal ground, attach it to “GND” on the terminal to the right of the
terminal for shield (SH) on the PCB. Then attach it to the corresponding terminal in the RTU.
Connecting shield
The shield in the RS485 cable should be connected to ground at the transformer and then continuously connect to
”SH” on all the UltraLinks that are powered from that transformer. If more than one transformer is used on the bus, the
shield is broken at each transformer so ”SH” on every product only has connection to ground at the transformer from
which its power is supplied.
BA
+B -A +B -A +B -A +B -A
GNDGND GNDGND
Signal ground
Shield ground
Biasing
The master on the bus must have biasing on
-A and +B. This is more or less standard on
BMS-controllers, but if communication should
be established with a conventional compu-
ter using a RS485-USB converter, then it is
important to make sure that the converter has
a bias circuit. If communication fails and you
are uncertain about existance of biasing,
you can add biasing resistors in the screw terminal on one of the UltraLinks to see if this is the cause of the com-
munication failure. Use 500 - 1000 Ω resistors and connect one resistor from -A to GND and one from +B to the 3V3
terminal. It is also recommendedto add a 120 Ω termination resistor between -A and +B on the last UltraLink on the
bus to avoid signal reflections.
Repeater
If the bus is longer than 300 meters or if there
are more than 30 devices, the system might
need an RS485 repeater (FDS-R, see picture
to the right) to be able to communicate in an
efficient way.

10
0,7
0,6
0,8
0,9
1
1,1
1,2
1,3
1,4
1,5
Wire cross section Area [ mm2 ]
0
0,1
0,2
0,3
0,4
0,5
0,20
0,15
0,100,050
Copper Resistance [ Ω/m ]
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Power supply
Transformer sizing
The needed size of 24 V AC transformer(s) can be defined by adding up the dimensioning power consumption [VA] of all
the components. The transformer power must exceed this. Use only safety isolating transformers. Calculation of the cur-
rent demand I:
I = (P1+P2+…+Pn) / U [A] where: Pnis the dimensioned power consumption for each component [VA] U is the voltage
(24) [V].
If the current demand I exceeds 6 A ( which corresponds to approximately 150 VA for a 24 V AC transformer ), it is neces-
sary to use more transformers to prevent overheating.
Supply cable sizing
The wire size of the supply cable can be determined by calculating the resistance per meter R. The calculation presuppo-
ses that a voltage drop of e.g. 2 V is accepted in the supply cable:
R(per m) = Udrop / (I * L) [Ω/m] where: Udrop is the accepted voltage drop (2 V) in the cable [V] I is the current [A]
L is the longest distance of supply cables from transformer to a component [m]
Wire cross section area as a function of resistance per m for copper wire
Example:
Udrop = 2 V, I = 4 A, L = 20 m
R (per m) = 2V / (4A × 20 m) = 0,025 Ω/m
In the diagram a Wire cross section Area of 0,7 mm² can be read.
Power consumption
The power consumption for dimensioning supply cables for an UltraLink®FTMU is 0,5 VA.
It is not recommended to use a transformer with a higher capacity than 150 VA.