Nibe SMO 20 User guide

Installer manual
LEK
SMO 20
Control module
IHB GB 1624-6
231758

Quick guide
Navigation
Ok button (confirm/select)
Back button (back/undo/exit)
Control knob (move/increase/reduce)
A detailed explanation of the button functions can be found on page 31.
How to scroll through menus and make different settings is described on page 33.
temperature1.1
Set the indoor climate
2X
INDOOR CLIMATE
HOT WATER
INFO
HEAT PUMP
The mode for setting the indoor temperature is accessed by pressing the OK button twice, when in the start mode
in the main menu.
INDOOR CLIMATE
HOT WATER
INFO
HEAT PUMP
off
temporary lux2.1
3 hrs
6 hrs
12 hrs
one time
increase
Increase hot water volume
2X
1X
To temporarily increase the amount of hot water (if a hot water heater is installed to your SMO 20), first turn the
control knob to mark menu 2 (water droplet) and then press the OK button twice.
In event of disturbances in comfort
If a disturbance in comfort of any type occurs there are some measures that can be taken before you need to
contact your installer. See page 46 for instructions.

Table of Contents
41 Important information
4Safety information
4General
72 Delivery and handling
7Mounting
7Supplied components
83 The Control Module Design
8Electrical components
94 Pipe connections
9General
9Compatible NIBE air/water heat pumps
9Symbol key
10Temperature sensor installation on pipe
10Docking alternatives
145 Electrical connections
14General
15Accessibility, electrical connection
16Cable lock
17Connections
20Optional connections
24Connecting accessories
256 Commissioning and adjusting
25Preparations
25
Commissioning with NIBE air/water heat
pump
25Commissioning with additional heating only
25Check the reversing valve
25Check AUX socket
25Cooling mode
26Start guide
27Setting the cooling/heating curve
29Setting hot water circulation
30SG Ready
317 Control - Introduction
31Display unit
32Menu system
358 Control
35Menu 1 - INDOOR CLIMATE
36Menu 2 - HOT WATER
36Menu 3 - INFO
37Menu 4 - MY SYSTEM
38Menu 5 - SERVICE
439 Service
43Service actions
4610 Disturbances in comfort
46Manage alarm
46Troubleshooting
47Additional heating only
4811 Accessories
5012 Technical data
50Dimensions and setting-out coordinates
51Technical specifications
52Energy labelling
53Electrical circuit diagram
57Index
3Table of Contents |SMO 20

Safety information
This manual describes installation and service procedures
for implementation by specialists.
This appliance can be used by children
aged from 8 years and above and per-
sons with reduced physical, sensory or
mental capabilities or lack of experience
and knowledge if they have been given
supervision or instruction concerning use
of the appliance in a safe way and under-
stand the hazards involved. Children shall
not play with the appliance. Cleaning
and user maintenance shall not be made
by children without supervision.
Rights to make any design or technical
modifications are reserved.
©NIBE 2016.
Symbols
NOTE
This symbol indicates danger to machine or
person.
Caution
This symbol indicates important information
about what you should observe when maintain-
ing your installation.
TIP
This symbol indicates tips on how to facilitate
using the product.
Marking
SMO 20 is CE marked and fulfils IP21.
The CE marking means that NIBE ensures that the
product meets all regulations that are placed on it based
on relevant EU directives. The CE mark is obligatory for
most products sold in the EU, regardless where they are
made.
IP21 means that objects with a diameter larger than or
equivalent to 12.5 mm cannot penetrate and cause
damage and that the product is protected against vertic-
ally falling drops of water.
General
Serial number
The serial number can be found on the top of the cover
for the control module and in the info menu (menu 3.1).
LEK
Serial number
Caution
Always give the product's serial number when
reporting a fault.
Recovery
Leave the disposal of the packaging to the in-
staller who installed the product or to special
waste stations.
Do not dispose of used products with normal
household waste. It must be disposed of at a
special waste station or dealer who provides this type of
service.
Improper disposal of the product by the user results in
administrative penalties in accordance with current legis-
lation.
Country specific information
Installer manual
This installer manual must be left with the customer.
SMO 20Chapter 1 | Important information4
1 Important information

Inspection of the installation
Current regulations require the heating installation to be inspected before it is commissioned. The inspection must
be carried out by a suitably qualified person. Fill in the page for information about installation data in the User
manual.
DateSignatureNotesDescription
✔
Electricity (page 14)
Communication, heat pump
Connected supply 230 V
Outside sensor
Temperature sensor, hot water charging
Temperature sensor, hot water top
Temperature sensor, external flow line
Temperature sensor, external supply line
after electric heater
Temperature sensor, external return line
Charge pump
Shuttle valve
AUX1
AUX2
AUX3
AUX4
AUX5
AUX6
AA2-X4
Miscellaneous
Checking additional heater
Checking the function of the reversing
valve
Checking charge pump function
Completed installation check of heat
pump and associated equipment
5Chapter 1 | Important informationSMO 20
......................................................................................................................................................................................................................................................................................................................................................................................................................................................................

Contact information
KNV Energietechnik GmbH, Gahberggasse 11, 4861 Schörfling
Tel: +43 (0)7662 8963-0 Fax: +43 (0)7662 8963-44 E-mail: mail@knv.at www.knv.at
AT
NIBE Wärmetechnik c/o ait Schweiz AG, Industriepark, CH-6246 Altishofen
CH
Druzstevni zavody Drazice s.r.o, Drazice 69, CZ - 294 71 Benatky nad Jizerou
CZ
NIBE Systemtechnik GmbH, Am Reiherpfahl 3, 29223 Celle
DE
Vølund Varmeteknik A/S, Member of the Nibe Group, Brogårdsvej 7, 6920 Videbæk
DK
NIBE Energy Systems OY, Juurakkotie 3, 01510 Vantaa
FI
NIBE Energy Systems France Sarl, Zone industrielle RD 28, Rue du Pou du Ciel, 01600 Reyrieux
FR
NIBE Energy Systems Ltd, 3C Broom Business Park, Bridge Way, Chesterfield S41 9QG
GB
NIBE Energietechniek B.V., Postbus 634, NL 4900 AP Oosterhout
NL
ABK AS, Brobekkveien 80, 0582 Oslo, Postadresse: Postboks 64 Vollebekk, 0516 Oslo
NO
NIBE-BIAWAR Sp. z o. o. Aleja Jana Pawła II 57, 15-703 BIAŁYSTOK
Tel: 085 662 84 90 Fax: 085 662 84 14 E-mail: sekretariat@biawar.com.pl www.biawar.com.pl
PL
© "EVAN" 17, per. Boynovskiy, Nizhny Novgorod
RU
NIBE AB Sweden, Box 14, Hannabadsvägen 5, SE-285 21 Markaryd
SE
For countries not mention in this list, please contact Nibe Sweden or check www.nibe.eu for more information.
SMO 20Chapter 1 | Important information6

Mounting
NOTE
For wall mounting, use the mounting adapted
for the base.
110
410
360
110
10
310
215
70
35
Use all mounting points and install SMO 20 upright flat
against the wall without any part of the control module
protruding out beyond the edge of the wall.
Leave at least 100 mm free space around the control
module to facilitate access and cable routing on installa-
tion and service.
NOTE
Access the screws for installing the front cover
from underneath.
Supplied components
Heating pipe pasteOutside sensor
LEK
Temperature sensorInsulation tape
LEK
Cable tiesAluminium tape
7Chapter 2 | Delivery and handlingSMO 20
2 Delivery and handling

LEK
L N 1 1 0 2 3 4PE
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
AA2
AA4-XJ3
X1
SF1
AA4
X2
AA7
AA4-XJ4
LEK
L N 1 1 0 2 3 4PE
AA2
X1
FA1
AA7
UB2UB1
PF3
Electrical components
Base cardAA2
Display unitAA4
AA4-XJ3 USB socket
AA4-XJ4 Service outlet (No function)
Extra relay circuit boardAA7
Miniature circuit-breakerFA1
Terminal block, incoming electrical supplyX1
Terminal block, control signal circulation pump,
sensors AUX inputs and heat pump
X2
SwitchSF1
Serial number platePF3
Cable grommet, incoming supply electricity,
power for accessories
UB1
Cable gland, signalUB2
Designations in component locations according to
standard IEC 81346-1 and 81346-2.
SMO 20Chapter 3 | The Control Module Design8
3 The Control Module Design

General
Pipe installation must be carried out in accordance with
current norms and directives. See manual for compatible
NIBE air/water heat pump for installation of the heat
pump.
Compatible NIBE air/water heat
pumps
Compatible NIBE air/water heat pumps must be
equipped with a control card that has at least the soft-
ware version given in the following list. The control card
version is displayed in the heat pump's display (if applic-
able) upon start-up.
Software versionProduct
55F2015
55F2016
118F2020
55F2025
55F2026
all versionsF2030
all versionsF2040
all versionsF2120
55F2300
Symbol key
MeaningSymbol
Shut-off valve
Tapping valve
Trim valve
Shunt / reversing valve
Safety valve
Temperature sensor
Expansion vessel
Pressure gauge
P
Circulation pump
Particle filter
Auxiliary relay
Compressor
Heat exchanger
Radiator system
Domestic hot water
Under floor heating systems
Cooling system
9Chapter 4 | Pipe connectionsSMO 20
4 Pipe connections

Temperature sensor installation
on pipe
LEK
LEK
The temperature sensors are mounted with heat con-
ducting paste, cable ties (the first cable tie is secured to
the pipe in the middle of the sensor and the other cable
tie is mounted approx. 5 cm beyond the sensor) and
aluminium tape. Then insulate with supplied insulation
tape.
NOTE
Sensor and communication cables must not be
placed near power cables.
Docking alternatives
SMO 20 can be connected with other products from
NIBE in several different ways, some of which are shown
below (accessories may be required).
Further option information is available at www.nibe.eu
and in the respective assembly instructions for the ac-
cessories used. See page 48 for a list of the accessories
that can be used with SMO 20.
Installations with SMO 20 can produce heating and hot
water. Cooling can also be produced, depending on
which heat pump is used.
On cold days of the year when the access to energy from
the air is reduced the additional heating can compensate
and help to produce heat. The additional heating is also
good to have as assistance if the heat pump ends up
outside its working range or if it has been blocked for
any reason.
NOTE
The heating medium side and the hot water
side must be fitted with the necessary safety
equipment in accordance with the applicable
regulations.
This is the outline diagram. Actual installations
must be planned according to applicable
standards.
SMO 20Chapter 4 | Pipe connections10

Explanation
SMO 20AA25
Outdoor sensor1)
BT1
Temperature sensor, hot water charging1)
BT6
Temperature sensor, hot water top1)
BT7
Temperature sensor, external supply line1)
BT25
Room sensorBT50
Temperature sensor, external supply line
after electric heater
BT63
Temperature sensor, external return line1)
BT71
Circulation pump, Heating mediumGP10
Reversing valve, Hot water/Heating medi-
um2)
QN10
Additional heatEB1
Immersion heaterEB1
Auxiliary relay/Contactor2)
KA1
Heat pump systemEB101
Temperature sensor, return line3)
BT3
Temperature sensor, condenser supply line3)
BT12
Heat pumpEB101
Safety valveFL10
Charge pump2)
GP12
Particle filter3)
HQ1
Drain valve, Heating mediumQM1
Shut-off valve, Heating medium, FlowQM31
Shut off valve, Heating medium, ReturnQM32
Shut-off valveQM43
Cooling systemEQ1
Temperature sensor, cooling supply line2)
BT64
Single jacket accumulator tank, coolingCP6
Circulation pump, coolingGP13
Reversing valve, Cooling/Heating2)
QN12
Miscellaneous
Expansion vessel closed, Heating mediumCM1
Buffer vessel (UKV)CP5
Accumulator tank with hot water heatingCP10
Immersion heaterEB20
Safety valve, Heating mediumFL2
Auxiliary relay/ContactorKA1
Trim valveRN10
1) Included in and supplied SMO 20
2) Included in and supplied accessory
3) Included in and supplied NIBE heat pump (can vary depending
on heat pump).
Designations according to standards 81346-1 and 81346-
2.
11Chapter 4 | Pipe connectionsSMO 20

Compatible NIBE air/water heat pump together with SMO 20 - docking step controlled
additional heat before reversing valve for hot water and cooling function (4 pipe system)
-FL2
-CM1
-EB101
-QM1
-BT3
-BT12 -QM31
-QM32 -QM43
-GP12
-EB101
-HQ1
-BT1
-AA25
-AA25
-BT50
-AA25
-BT63
-KA1
-EB1
-FL10
-RN10
-CP10
-AA25-QN10
-AA25-BT7
-AA25-BT6
-GP13
-CP6
-BT64
-EQ1-QN12
-EQ1
-EB1
NOTE
NIBE does not supply all components in this
outline diagram.
SMO 20 (AA25) starts and stops the heat pump (EB101)
to meet the heat and hot water demand of the installa-
tion. At simultaneous heating and hot water demand
the reversing valve switches (AA25-QN10) periodically
between the climate system and the water heater/accu-
mulator tank (CP10). When the hot water heater/accu-
mulator tank is fully charged (CP10), the reversing valve
switches (AA25-QN10) to the climate system.
Additional heat (EB1) is connected automatically when
the power demand for the installation exceeds the heat
pump capacity. This is used for both heating and char-
ging hot water.
The additional heat can also be used if a higher temper-
ature in the hot water is required than the heat pump
can produce.
During cooling operation (requires compatible heat
pump) the reversing valve (EQ1-QN12) switches to the
cooling system (EQ1). If several simultaneous demands
occur while there is a cooling demand the installation
reacts differently. In event of a hot water demand the
reversing valve (EQ1-QN12) switches back and hot water
is produced until the demand is fulfilled. In event of a
heating demand the reversing valve (EQ1-QN12) instead
switches periodically between the demands. If the cool-
ing demand is met, the reversing valve switches back to
basic mode (heat/hot water).
SMO 20Chapter 4 | Pipe connections12

Compatible air/water heat pump together with SMO 20 - docking step controlled additional
heat after reversing valve for hot water and cooling function (4 pipe system)
-EB20
-KA1
-FL2
-CM1
-EB101
-QM1
-BT3
-BT12 -QM31
-QM32 -QM43
-GP12
-EB101
-HQ1
-BT1
-AA25
-AA25 -AA25
-FL10
-RN10
-CP10
-AA25-QN10
-AA25-BT7
-AA25-BT6
-BT25
-EB1
-CP5
-GP10
-KA1
-BT71
-EB1
-AA25
-GP13
-CP6
-BT64
-EQ1-QN12
-EQ1
-BT50
NOTE
NIBE does not supply all components in this
outline diagram.
This installations alternative is suitable for more complex
installations with a focus on comfort.
SMO 20 (AA25) starts and stops the heat pump (EB101)
to meet the heat and hot water demand of the installa-
tion. At simultaneous heating and hot water demand
the reversing valve switches (AA25-QN10) periodically
between the climate system and the water heater/accu-
mulator tank (CP10). When the hot water heater/accu-
mulator tank is fully charged (CP10), the reversing valve
switches (AA25-QN10) to the climate system.
Additional heat (EB1) is connected automatically when
the energy demand exceeds the heat pump capacity.
Immersion heater (EB20) in the water heater/accumulat-
or tank (CP10) is used during the time to produce hot
water if the heat pump (EB101) is used for heating the
building at the same time.
The immersion heater (EB20) can also be used if a higher
temperature of hot water is required than the heat pump
can produce.
During cooling operation (requires compatible heat
pump) the reversing valve (EQ1-QN12) switches to the
cooling system (EQ1). If several simultaneous demands
occur while there is a cooling demand the installation
reacts differently. In event of a hot water demand the
reversing valve (EQ1-QN12) switches back and hot water
is produced until the demand is fulfilled. In event of a
heating demand the reversing valve (EQ1-QN12) instead
switches periodically between the demands. If the cool-
ing demand is met, the reversing valve switches back to
basic mode (heat/hot water).
13Chapter 4 | Pipe connectionsSMO 20

General
■Disconnect SMO 20 before insulation testing the house
wiring.
■If the building is equipped with an earth-fault breaker,
SMO 20 should be equipped with a separate one.
■SMO 20 must be installed via a circuit breaker with a
minimum breaking gap of 3 mm.
■For the electrical wiring diagram for the control mod-
ule, see page .53.
■Communication and sensor cables to external connec-
tions must not be laid close to high current cables.
■The minimum area of communication and sensor
cables to external connections must be 0.5 mm² up to
50 m, for example EKKX, LiYY or equivalent.
■Use a screened three core cable for communication
with the heat pump.
■When cable routing into SMO 20, cable grommets
(UB1 and UB2, marked in image) must be used.
NOTE
The switch (SF1) must not be moved to "" or
" " until the boiler in the system has been filled
with water. The compressor in the heat pump
and any external additional heat can be dam-
aged.
NOTE
Electrical installation and service must be carried
out under the supervision of a qualified electri-
cian. Cut the current with the circuit breaker
before carrying out any servicing. Electrical in-
stallation and wiring must be carried out in ac-
cordance with the stipulations in force.
When installing SMO 20, NIBE's air/water heat
pump and any addition must be current free.
NOTE
See outline diagram for your system for physical
location of the temperature sensor that is to be
installed.
LEK
L N 1 1 0 2 3 4PE
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
SF1
FA1
UB2UB1
Miniature circuit-breaker
The control module operating circuit and parts of its in-
ternal components are internally fused by a miniature
circuit breaker (FA1).
SMO 20Chapter 5 | Electrical connections14
5 Electrical connections

Accessibility, electrical
connection
The cover of the control module is opened using a Torx
25 screwdriver. Assembly takes place in the reverse order.
3
1
2
LEK
LEK
NOTE
The cover to access the base board is opened
using a Torx 25 screwdriver.
3
1
2
LEK
LEK
The display may need to be moved for easier access when
connecting electrics. This is easily done by following these
steps.
1.
LEK
LEK
LEK
LEK
b
a
Press in the catch on the upper rear side of the dis-
play unit towards you (a) and move the display unit
upwards (b) so that the mountings unhook from the
panel.
2.
LEK
LEK
LEK
LEK
b
a
Lift the display unit from its mountings.
3.
LEK
LEK
LEK
LEK
b
a
Align the two lower mountings on the reverse of the
display unit with the two upper holes in the panel
as illustrated.
15Chapter 5 | Electrical connectionsSMO 20

4.
LEK
LEK
LEK
LEK
b
a
Secure the display on the panel.
5. When the electrical connection is ready the display
must be reinstalled with three mounting points
again, otherwise the front cover cannot be installed.
Cable lock
Use a suitable tool to release/lock cables in the heat
pump terminal blocks.
Terminal block on the electrical card
LEK
1
1
2
2
3
3
1
2
3
3
4
1
2
LEK
1
1
2
2
3
3
1
2
3
3
4
1
2
1
2
Terminal block
LEK
1 mm
3,5 mm
LEK
1 mm
3,5 mm
SMO 20Chapter 5 | Electrical connections16

Connections
NOTE
To prevent interference, unscreened communic-
ation and/or sensor cables to external connec-
tions must not be laid closer than 20 cm from
high voltage cables.
Power connection
SMO 20 must be installed via an isolator switch with a
minimum breaking gap of 3mm. Minimum cable area
must be sized according to the fuse rating used.
1N
L
X1
LEK
L N 1 1 0 2 3 4PE
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
X1
1 1N
L0 432PE
Tariff control
If the voltage to the compressor in the heat pump disap-
pears for a certain period, simultaneous blocking of these
must take place via software controlled input (AUX input)
to avoid alarm, see page 22.
Connecting the charge pump for the heat
pump
Connect circulation pump (EB101-GP12) to terminal
block X4:5 (PE), X4:6 (N) and X4:7 (230 V) on the base
board (AA2) as illustrated.
Connect control signal for (EB101-GP12) to terminal
block X2:1 (PWM) and X2:2 (GND) as illustrated.
987654
SMO
Externt
PE
L
N
External
SMO20
AA2-X4
EB101-GP12
LEK
L N 1 1 0 2 3 4PE
AA2-X4
2
1
4
3
SMO
Externt
External
SMO20
X2
EB101-GP12
PWM
GND
LEK
L N 1 1 0 2 3 4PE
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
X2
5
6
7
2
1
8
9
13
12
4
3
11
10
19
20
21
14
18
16
17
15
17Chapter 5 | Electrical connectionsSMO 20

Communication with heat pump
Connect the heat pump (EB101) with a screened three
core cable to terminal block X2:19 (A), X2:20 (B) and
X2:21 (GND) as illustrated.
LEK
L N 1 1 0 2 3 4PE
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
X2
5
6
7
2
1
8
9
13
12
4
3
11
10
19
20
21
14
18
16
17
15
A
B
GND
SMO
19
20
21
18
F2120
2
1
3
4
GND
B
A
6
5
4
3
2
1
A
B
GND
A
B
GND
F2040
A
B
GND
F2030
542 3
1
A
B
GND
F2016/F2026
5 64
2 3
1
A
B
GND
F2015/F2020/F2025/F2300
X2
SMO20
AA21-J2
X5
X5
AA23-X4
X22
Outside sensor
Install the outdoor temperature sensor (BT1) in the shade
on a wall facing north or north-west, so it is unaffected
by the morning sun for example.
Connect the sensor to terminal block X2:3 and X2:6. Use
a twin core cable with a cable area of at least 0.5 mm².
If a conduit is used it must be sealed to prevent condens-
ation in the sensor capsule.
SMO Externt
5
6
7
2
1
4
3
ExternalSMO20
X2
BT1
LEK
L N 1 1 0 2 3 4PE
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
X2
5
6
7
2
1
8
9
13
12
4
3
11
10
19
20
21
14
18
16
17
15
Temperature sensor, hot water charging
The temperature sensor, hot water charging (BT6) is
placed in the submerged tube on the water heater.
Connect the sensor to terminal block X2:5 and X2:6. Use
a twin core cable with a cable area of at least 0.5 mm².
Hot water charging is activated in menu 5.2 or in the
start guide.
SMO Externt
5
6
7
2
1
4
3
ExternalSMO20
X2
BT6
LEK
L N 1 1 0 2 3 4PE
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
X2
5
6
7
2
1
8
9
13
12
4
3
11
10
19
20
21
14
18
16
17
15
Temperature sensor, hot water top
A temperature sensor for hot water top (BT7) can be
connected to SMO 20 to show the water temperature
at the top of the tank (if it is possible to install a sensor
at the top of the tank).
Connect the sensor to terminal block X2:4 and X2:6. Use
a twin core cable with a cable area of at least 0.5 mm².
SMO Externt
5
6
7
2
1
4
3
ExternalSMO20
X2
BT7
LEK
L N 1 1 0 2 3 4PE
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
X2
5
6
7
2
1
8
9
13
12
4
3
11
10
19
20
21
14
18
16
17
15
SMO 20Chapter 5 | Electrical connections18

Temperature sensor, external flow line
Connect the temperature sensor, external supply line
(BT25) (required for additional heat after reversing valve
(QN10), to terminal block X2:8 and X2:10. Use a twin
core cable with a cable area of at least 0.5 mm².
SMO Externt
9
10
11
6
8
7
ExternalSMO20
X2
BT25
LEK
L N 1 1 0 2 3 4PE
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
X2
5
6
7
2
1
8
9
13
12
4
3
11
10
19
20
21
14
18
16
17
15
Temperature sensor, external supply at
additional heat before reversing valve (QN10)
Connect the temperature sensor, external supply line
(BT63) (required for additional heat before the reversing
valve for hot water charging (QN10), to terminal block
X2:9 and X2:10. Use a twin core cable with a cable area
of at least 0.5 mm².
SMO Externt
9
10
11
6
8
7
ExternalSMO20
X2
BT63
LEK
L N 1 1 0 2 3 4PE
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
X2
5
6
7
2
1
8
9
13
12
4
3
11
10
19
20
21
14
18
16
17
15
NOTE
For docking that requires connection of other
sensors. See "Possible selection for AUX inputs"
on page 22.
19Chapter 5 | Electrical connectionsSMO 20

Optional connections
Room sensor
SMO 20 can be supplemented with a room sensor (BT50).
The room sensor has up to three functions:
1. Show current room temperature in the control
module display.
2. Provides the option of changing the room temperat-
ure in °C.
3. Makes it possible to change/stabilise the room
temperature.
Install the sensor in a neutral position where the set
temperature is required. A suitable location is on a free
inner wall in a hall approx. 1.5 m above the floor. It is
important that the sensor is not prevented from measur-
ing the correct room temperature by being located, for
example, in a recess, between shelves, behind a curtain,
above or close to a heat source, in a draft from an extern-
al door or in direct sunlight. Closed radiator thermostats
can also cause problems.
The control module operates without the sensor, but if
you want to read off the accommodation's indoor tem-
perature in SMO 20's display the sensor must be installed.
Connect the room sensor to terminal block X2:7 and
X2:10.
If the sensor is to be used to change the room temperat-
ure in °C and/or to change/stabilise the room temperat-
ure, the sensor must be activated in menu 1.9.4.
If the room sensor is used in a room with underfloor
heating, it should only have an indicatory function, not
control of the room temperature.
SMO Externt
9
10
11
6
8
7
ExternalSMO20
X2
BT50
LEK
L N 1 1 0 2 3 4PE
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
X2
5
6
7
2
1
8
9
13
12
4
3
11
10
19
20
21
14
18
16
17
15
Caution
Changes of temperature in accommodation
take time. For example, short time periods in
combination with underfloor heating will not
give a noticeable difference in room temperat-
ure.
Step controlled additional heat
NOTE
Mark up any junction boxes with warnings for
external voltage.
External step controlled additional heat can be controlled
by up to three potential-free relays in the control module
(3 step linear or 7 step binary). Alternatively two relays
(2 step linear or 3 step binary) can be used for step con-
trolled additional heat, which means that the third relay
can be used to control the immersion heater in the water
heater/accumulator tank.
Step in occurs with at least 1 minute interval and step
outs with at least 3 seconds interval.
Step 1 is connected to terminal block X2:2 on the addi-
tional relay board (AA7).
Step 2 is connected to terminal block X2:4 on the addi-
tional relay board (AA7).
Step 3 or immersion heater in the water heater/accumu-
lator tank is connected to terminal block X2:6 on the
additional relay board (AA7).
The settings for step controlled additional heat are made
in menu 4.9.3 and menu 5.1.12.
All additional heat can be blocked by connecting a po-
tential-free switch function to the software controlled
input on terminal block X2 (see page 22) which is selec-
ted in menu 5.4.
SMO
Externt
654321
1 0 PE
A1
A2
A1
A2
A1
-K1 -K2 -K3
A2
External
SMO20
AA7-X2X1
LEK
L N 1 1 0 2 3 4PE
X1
1 1N
L0 432PE
-X2
1
12 3 4 56
23456
-X1
AA7-X2
If the relays are to be used for control voltage, bridge
the supply from terminal block X1:1 toX2:1, X2:3 and
X2:5 on additional relay board (AA7). Connect the
neutral from the external additional heat to terminal
block X1:0.
With step controlled additional heat before the
reversing valve
The electric additional heat will charge with the maxim-
um permitted immersion heater output together with
the compressor to conclude the hot water charging and
return to charging the heating as soon as possible. This
only occurs when the number of degree minutes is below
the start value for the additional heat.
SMO 20Chapter 5 | Electrical connections20
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