LK Systems ETO2 User manual

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Function
When the ground sensor detects moisture while
the ground temperature is so low that there is a
freezing hazard, the control unit starts snow melt-
ing via the external control equipment. When the
ground sensor is dry, the snow melting is shut
off. The unit can be programmed to maintain the
heating activated for the desired time even if the
ground sensor is dry.
1. Install the control unit indoors either direct-
ly on the wall or on the DIN rail.
2. Start/stop signal to the property's BMS
is drawn from the pump inlet in the LK
Control unit ETO2 terminals 3, 4. (NOTE!
Potential-free contact).
3. Connect the LK Ground sensor ETOG ac-
cording to the instruction under the head-
ing LK Ground sensor ETOG.
4. Pump and actuator are not connected to the
LK Control unit ETO2 in this case.
5. Connect the power supply, see the circuit
diagram.
6. Adjust the control unit, see the heading
Adjustment to start/stop of external control
equipment.
Design
LK Control Unit ETO2 is meant to be used pri-
marily as LK Snow melting must be controlled in-
termittently. The equipment consists of LK Con-
trol Unit ETO2, LK Ground sensor ETOG and LK
Pipe sensor ETF.
LK Control Unit ETO2 offers the following:
• Energy-efcient control of the snow melting
system.
• Simple menu navigation.
• Clear background-lit display.
• Alarm relay.
Note!
The control unit can, depending on how it is set,
either maintain/regulate the ow temperature to
the snow melting system or only generate start/
stop signals to the external control equipment.
The instruction is divided into two different chap-
ters depending on the function desired. If the unit
should maintain/regulate the ow temperature,
follow the instructions Assembly instruction,
Maintaining the ow temperature. If the unit
should send start/stop signals to external control
equipment, follow the instructions below.
Assembly instruction, start/stop of
external control equipment (BMS)
The following instruction is applicable when
LK Control unit ETO2 must send start/stop sig-
nals to the external control equipment. The con-
trol unit and sensor must only be installed by an
authorized electrician.
LK Control Unit ETO2
EN.31.C.5.1907
Assembly instructions | LK Control Unit ETO2

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EN.31.C.5.1907
Assembly instructions | LK Control Unit ETO2
The unit can also control the start/stop function
of the circulation pump in the snow melting sys-
tem. When the ground sensor is dry, the snow
melting is shut off. The unit can be programmed
to maintain the heating activated for the desired
time even if the ground sensor is dry.
1. Install the control unit indoors either direct-
ly on the wall or on the DIN rail.
2. Connect the LK Ground sensor, see the cir-
cuit diagram under the heading LK Ground
sensor.
3. Connect the LK Pipe sensor, see the circuit
diagram under the heading LK Pipe sensor.
4. Connect the actuator, see the circuit dia-
gram under the heading Actuator.
5. Connect the system's circulation pump,
see the circuit diagram under the heading
Pump relay.
6. Connect the power supply, see the circuit
diagram and the heading Supply voltage.
7. Adjust the control unit, see the heading Ad-
justment, Maintain the ow temperature.
Adjustment, maintain the flow temperature.
First time the control unit is charged, it must be
adjusted to the snow melting system. The adjust-
ment is done with the unit's multifunction button
(MF-button). Turn until the right menu is shown
on the display, conrm by pressing the button
once.
Note!
For the following description to be correct, it is
important that the unit is not powered up earlier.
If this has been done, the unit needs to be reset,
see REINSTALL in the table under Settings.
1. Select Celsius degrees, conrm by pressing
the MF button.
2. Select Sensor ETOG, conrm by pressing
the MF button.
3. Set Sensor 2* to OFF, conrm by pressing
the MF button.
4. Set Outdoor sensor to OFF, conrm by
pressing the MF button.
5. Set Application to Water based, conrm by
pressing the MF button.
6. The unit changes to normal view and the
Adjustment to start/stop of external control
equipment.
First time the control unit is charged, it must be
adjusted to the snow melting system. The adjust-
ment is done with the unit's multifunction button
(MF-button). Turn until the right menu is shown
on the display, conrm by pressing the button
once.
Note!
For the following description to be correct, it
is important that the unit is not powered up
earlier. If this has been done, the unit needs to
be reset, see REINSTALL in the table under the
heading Settings.
1. Select Celsius degrees, conrm by pressing
the MF button.
2. Select Sensor ETOG, conrm by pressing
the MF button.
3. Set Sensor 2* to OFF, conrm by pressing
the MF button.
4. Set Outdoor sensor to OFF, conrm by
pressing the MF button.
5. Set Application to ELECTRIC 1-zone,
conrm by pressing the MF button.
6. The unit changes to normal view and the
system is now ready for operation.
* Read more about sensor 2 under the heading
Ground sensor.
Assembly instruction, Maintaining
the flow temperature.
The following instruction is applicable for when
LK Control Unit ETO2 is to maintain/regulate
the feed temperature to the snow melting system.
The control unit and sensor may only be installed
by an authorized electrician.
Function
When the ground sensor detects moisture, and
the ground temperature is so low that there is
a freezing hazard, the control unit starts snow
melting by activating the control valve via the
motor/actuator. The control unit keeps the ow
temperature constant to the desired level with
the help of a ow sensor (LK Pipe sensor ETF).

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EN.31.C.5.1907
Assembly instructions | LK Control Unit ETO2
system is now ready for operation.
7. Check that MY Water is set to 5 degrees, see
the heading Settings.
8. Before the system is started, the maximum
temperature value must be controlled, see
the heading Settings/MAX WATER.
* Read more about sensor 2 under the heading
Ground sensor.
Principle drawing, control via 3-way valve.

4 (10)
EN.31.C.5.1907
Assembly instructions | LK Control Unit ETO2
The ground sensor must be installed by an au-
thorized electrician in accordance with applicable
regulations.
The connection is carried out according to the cir-
cuit diagram and below table:
Terminal number in the
control unit
Cable color, LK Ground
sensor 1
11 Brown
12 Green
13 Grey
14 Pink
15 Yellow
16 White
Connection of additional LK Ground sensor
(Sensor 2)
In case two ground sensors are required, sensor
number two is connected according to the circuit
diagram and the table below.
Terminal number in the
control unit
Cable color, LK Ground
sensor 2
11 Brown
12 Green
17 Grey
18 Pink
19 Yellow
20 White
When the extra sensor is installed, it must be ac-
tivated in the control unit for it to work. The ac-
tivation is done when the control unit is adjusted
to the LK Snow melting. Follow the instruction
under the heading Adjustment, Maintain the
ow temperature and Adjustment to start/stop
of external control equipment, but set Sensor 2 to
ON (point 3 in the instruction).
LK Ground sensor ETOG
Function
LK Ground sensor ETOG detects both tempera-
ture and moisture. Usually, it is enough to con-
nect one LK Ground sensor ETOG to the control
unit but in some cases, two ground sensors may
be required to achieve a satisfactory function, for
example a ground area that stretches around the
building and thereby extends to both North and
South locations.
Placement in the ground.
1. LK Ground sensor ETOG must be placed in
the ground within the heated area, where
snow/ice is suspected to remain for the
longest duration. The sensor is placed in
between two pipes
2. Prepare the assembly by drawing one
electric pipe to the place where the sensor is
to be installed. Place a wooden block or an-
other "template" instead of the sensor until
the ground surface is ready.
3. Then install the sensor at the top of the
ground surface using the delivered metal
plate template. Make sure that the sensor is
horizontal with the ground. NOTE! Make
sure that the sensor is installed with the
right side up. (The screw hole in the sensor
should be upwards).
4. Seal with concrete around the sensor so that
it is xed in the correct position.
Placement of the LK Ground sensor ETOG in the ground.
Connection
On delivery, the sensor is provided with a 10 me-
ter connection cable which is possible to extend
up to 200 m. Use an installation cable with at
least 6 pcs of 1,5 mm² threads. The cable should
be shielded and must not be installed in paral-
lel with current cables as this can lead to signal
disturbance.

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EN.31.C.5.1907
Assembly instructions | LK Control Unit ETO2
Connection the LK Pipe sensor, supply
The sensor intended to measure the supply tem-
perature is connected according to the circuit dia-
gram and the table below.
Terminal number LK Pipe sensor, supply
27 Electrical conductor, any color*
28 Electrical conductor, any color*
*The sensor has no polarity
Connection LK Pipe sensor, return
The unit is delivered with a built-in 10 kOhm
resistor between terminals 29 and 30, which
means that the unit believes the return tem-
perature to be constant at approx. 30 degrees.
Only in cases where a system must have a high
readiness for snow melting, such as a helipad
or ambulance intake, the resistor is replaced
by the LK Pipe sensor for measuring the re-
turn temperature. With a return temperature
sensor installed, the control unit will start the
snow melting when the return temperature is be-
low the set value.
The sensor to measure the return temperature is
connected according to the circuit diagram and
the table below.
Note!
A sensor installed as shown below means a
strong increase in the system's energy consump-
tion. Unless the system has access to waste heat/
free heat, carefully consider installing this.
Terminal number LK Pipe sensor, return
29 Electrical conductor, any color*
30 Electrical conductor, any color*
*The sensor has no polarity
Calibration of the ground sensor
If necessary, the temperature value for the ground
sensor can be calibrated according to the instruc-
tions below:
1. Disconnect the sensor cables that are con-
nected to terminals 11 and 12. (Feed to heat
element).
2. Wait for a few hours until the sensor and
the ground attain the same temperature.
3. Measure the actual ground temperature
with the external measuring equipment,
compare with the value that is shown on
the display.
4. Set the OFFSET temperature for the
current sensor.
5. Connect the sensor cables to terminals 11
and 12. (Feed to heat element).
Note!
The temperature displayed for the ground sensor
is always the ground temperature (core tempera-
ture in the sensor).
LK Pipe sensor ETF
Function
LK Pipe sensor measures the temperature of the
snow melting system's supply pipe in order for
the control unit to be able to maintain/regulate
the supply temperature at the set level. The pipe
sensor is connected when the control unit must
regulate/control the supply temperature.
Assembly on pipes
Assemble the sensor to a suitable location on the
supply pipe, using the mounting strap supplied.
Clean the surface properly so that good contact
is attained. If necessary, the sensor body can be
insulated to avoid incorrect measurement data.

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EN.31.C.5.1907
Assembly instructions | LK Control Unit ETO2
Selected mode Application* Function relay
Start/stop of
BMS
Electric mode
1 zone
Relays 1, 2 and 3 ener-
gized at the same time
Start/stop of
BMS
Electric mode
2 zone
Relay 1 is energized
where zone 1 is active.
Relay 2 is energized
where zone 2 is active.
Maintain ow
temperature
Water based Relay 1 and relay 2 are
energized at the same
time. Relay 3 is unaf-
fected.
* See the heading adjustment below
Connection of supply voltage
Connection of supply voltage is carried out ac-
cording to the circuit diagram.
Remote control
Remote control, forced start
The control unit is equipped with an input to
remotely control/force start the system even if
there is no "real" need. On activated input (closed
contact), the heat is connected and continues un-
til the after heating time reaches value zero. Re-
mote control of forced start is connected between
terminals 35 and 36.
FORCED
CONTROL
HEAT
ETO2
Remote control, forced standby
Forced Standby is used when you don´t want the
unit to start even if there is a need. On activated
input (closed contact), a forced standby is activat-
ed. The function is connected between terminals
33 and 34.
Actuator
LK Control unit ETO2 sends control signals to
impact the 0-10 V actuator (24 V AC 0-10 V, not
LK item). The actuator is connected according to
the table below.
Principle drawing, connection of 0-10 V actuator.
Terminal number Connect to:
21 COM on actuator
22 Control signal (0-10 V)
23 Strapped to terminal 21
24 24 V AC feed to actuator
25, 26 Transformer 24 V AC
Pump relay
The control unit is equipped with three potential-
free relays (not powered), which if necessary,
can start/stop the system's primary/secondary
pumps or be used to start/stop the external con-
trol equipment. Connection is made according to
the circuit diagram.
Depending on how the device has been set, the
relays have different functions, see table below.

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EN.31.C.5.1907
Assembly instructions | LK Control Unit ETO2
STAND
BY
ETO2
Menus/Settings
All menu management and conguration of all
settings is done using the multi-function button
(MF button). Turn until the right menu is shown
on the display, conrm by pressing the button
once.
Normal view
When the unit is powered, the display shows a
normal view with information on the unit's oper-
ation mode. By pressing the MF button once, the
display shows more detailed information about
the operation mode. See below a list of the infor-
mation displayed in the normal view.
Display text Explanation
ZONE 1 ON = Heating activated for zone 1.
OFF = Heating deactivated for zone 1.
ZONE 2 ON = Heating activated for zone 2.
OFF = Heating deactivated for zone 2.
SENSOR 1 Shows the ground temperature for ground
sensor 1. Note! Does not show the air
temperature.
SENSOR 2 Shows the ground temperature for ground
sensor 1.
Note! Does not show the air temperature.
MOIST 1 Moisture status for sensor 1, YES, NO or
blank value. Blank value is displayed if the
temperature is above the set start value or
if the unit is operating in Afterrun mode.
MOIST 2 Moisture status for sensor 2, YES, NO, or
blank value. Blank value is displayed if the
temperature is above the set start value or
if the unit is operating in Afterrun mode.
OUT TEMP Air temperature outdoors, not used for
snow melting.
SUPPLY W. Temperature of the supply water
RETURN W. Temperature of the return water.

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EN.31.C.5.1907
Assembly instructions | LK Control Unit ETO2
Settings
Settings are made under the heading Setup. The menu becomes accessible by pressing the MF button once,
when the unit's display is in normal view. Thereafter, select SETUP and conrm with the MF button.
Below is a list of the different menus available under SETUP and the options available under the menus.
Function Description Selectable value
FORCE HEAT Used to force the snow melting to start. Snow melting is
activated for the time given under the heading Afterrun.
Select ON or OFF.
SELECT SCALE Indicates the temperature scale to be used Select C or F.
SET TEMP 1 For the unit to start, the temperature must be below the
given value. (The value refers to ground sensor 1.)
Select between -20 - + 50 ºC.
Default + 3 ºC
SET TEMP 2 For the unit to start, the temperature must be below the
given value. (The value refers to ground sensor 2.)
Select between -20 - + 50 ºC.
AFTERRUN 1 Indicates how long the unit continues to operate after ground
sensor 1 perceives the ground surface as dry.
Select from 0 minutes to 18 hours.
AFTERRUN 2 Indicates how long the unit continues to operate after ground
sensor 2 perceives the ground surface as dry.
Select from 0 minutes to 18 hours.
SET TEMP 1 Lowest start temperature for ground sensor 1. Select between -20 up to the adjusted
SET TEMP 1 or OFF (OFF = no limit.)
SET TEMP 2 Lowest start temperature for ground sensor 2. Select between -20 up to the adjusted
SET TEMP 2 or OFF (OFF = no limit.)
OFFSET T1 Used to calibrate ground sensor 1, see Calibration heading. Select between -5 to + 5 ºC
OFFSET T2 Used to calibrate ground sensor 2, see Calibration heading. Select between -5 to + 5 ºC
OFFSET OUT The function is not used for snow melting. -
MIN WATER Indicates the lowest return temperature for the system. On
delivery, the unit is provided with a resistor instead of a re-
turn temperature sensor. The resistor corresponds to a xed
return temperature of 30 ºC.
Select between 0 and 40 ºC.
Default + 3 ºC
MAX WATER States the highest supply temperature for the system.
NOTE! MAX VALUE is 50 ºC for LK Snow melting.
Select between 0 and 60 ºC.
FACTORY RESET Reset the unit to factory setting. Select EXIT or RESET
Sensor Heat Auto When snow melting is activated, the heat-supply to the
sensor is switched o󰀨. In case of extreme circumstances,
heating of the sensor may occur continuously.
Select Auto or ON
MOIST CTRL The ground sensor's moisture sensor can be switched o󰀨.
Then the power on/o󰀨 of the snow melting is controlled only
on the basis of the set temperature.
NOTE! When OFF is selected, the energy consumption
increases signicantly.
Select ON or OFF
SENSITIVITY The sensor's moisture sensitivity has ve settings. MN, LOW, NORM, HIGH and MAX
REINSTALL Facilitates re-installation of the unit. CODE is 1202. -
EXIT Exit menu setup. -

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EN.31.C.5.1907
Assembly instructions | LK Control Unit ETO2
Circuit diagram
230 V AC Fuse
1
4
3
2
LK Systems
11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
3456781-1-2NL
On
Alarm
No. Sensor
1 LK Ground sensor 1 ETOG
2 LK Ground sensor 2 ETOG, connected only if
necessary
3 LK Pipe sensor ETF, supply.
4 LK Pipe sensor ETF, return. Connected only if
necessary.
Alarm
If an error occurs in the unit, it is indicated with a
blinking LED-marked alarm.
Do the following to see the alarm in clear text:
1. Press once on the MF button, select
ALARM, conrm with the MF button.
2. The alarm is now shown in clear text, see
the table below.
Alarm Explanation
RETURN TEMP LOW Too low return temperature
SUPPLY TEMP HIGH Too high ow temperature
RETURN SENSOR Defect return sensor
SUPPLY SENSOR Defect supply sensor
TEMP SENSOR 1 Defect ground sensor 1
TEMP SENSOR 2 Defect ground sensor 2
OUTDOOR SENSOR Defect outdoor sensor
SENSOR HEATER Short-circuiting of the heating
element in the ground sensor
FROST PROTECT Frost protection activated due to
return temperature being too low
Interruption in the ground sensor
If there is an interruption in the ground sensor,
the unit sends an alarm and at the same time,
switches off the snow melting system.
Function control
After the connection and adjustment a function
control must be performed.
1. Increase SET TEMP to max, see the heading
Menus/settings.
2. Pour water on the ground sensor.
3. Check that the control unit display shows
ON.
4. Reset SET TEMP to the desired value
(default + 3 ºC).

10 (10)
Terminal No./
Symbol
Connected to: Note
11 LK Ground sensor 1, Brown cable Where applicable even connected to ground sensor 2, Brown cable.
12 LK Ground sensor 1, Green cable Where applicable even connected to ground sensor 2, Green cable.
13 LK Ground sensor 1, Grey cable
14 LK Ground sensor 1, Pink cable
15 LK Ground sensor 1, Yellow cable
16 LK Ground sensor 1, White cable
17 LK Ground sensor 2, Grey cable NOTE! LK Ground sensor 2 is connected only if needed, see the
heading LK Ground sensor ETOG.
18 LK Ground sensor 2, Pink cable NOTE! LK Ground sensor 2 is connected only if needed, see the
heading LK Ground sensor ETOG.
19 LK Ground sensor 2, Yellow cable NOTE! LK Ground sensor 2 is connected only if needed, see the
heading LK Ground sensor ETOG.
20 LK Ground sensor 2, White cable NOTE! LK Ground sensor 2 is connected only if needed, see the
heading LK Ground sensor ETOG.
21 Com on actuator Use 0-10 V actuator with 24 AC supply.
22 Control signal (0-10V) Use 0-10 V actuator with 24 AC supply.
23 Strapped to terminal 21
24 24 VAC supply to actuator Use 0-10 V actuator with 24 AC supply.
25, 26 Transformer 24 V AC
27 LK Pipe sensor, supply, Blue cable
28 LK Pipe sensor, supply, Brown cable
29 LK Pipe sensor, return, Blue cable NOTE! LK Pipe sensor 2 is connected only if needed, see the head-
ing LK Pipe sensor ETF.
30 LK Pipe sensor, return, Brown cable NOTE! LK Pipe sensor 2 is connected only if needed, see the head-
ing LK Pipe sensor ETF.
31, 32 Not used
33, 34 GSM-switch or other remote control Remote standby, closed contact switches of snow melting in ad-
vance.
35, 36 GSM-switch or other remote control Closed contact forces the unit to start, connected only if needed.
N, L 230 VAC
1-1, 2 Alarm output Max. load 5A.
3, 4 Pump or BMS Potential-free contact, Max. load 16A.
5, 6 Pump or BMS Potential-free contact, Max. load 16A.
7, 8 Pump or BMS Potential-free contact, Max. load 16A.
Technical Data
LK Control Unit ETO2
Article number 538 61 76
Dimensions 170 x 162 x 45
Weight 0.5 kg
Cable protection class IP20
Ambient temperature 0-50 °C
LK Ground sensor ETOG
Article number 538 61 77
Dimensions 32 mm x Ø 60 mm
Weight 1.0 kg
Cable protection class IP68
Ambient temperature -20 - +70 ºC
Cable length 10 m
Max cable length for extension 200 m
LK Pipe sensor ETF
Article number 538 61 78
Dimensions 40 mm x Ø 12 mm
Weight 0.1 kg
Ambient temperature -20 - + 70 ºC
Cable length 2.5 m
Sensor element NTC 12 k @25 C
EN.31.C.5.1907
Assembly instructions | LK Control Unit ETO2
LK Systems AB, Box 66, SE-161 26 Bromma, Sweden | www.lksystems.se/en