Tekmar 1873-ESM Guide

Ice and Snow Detector
1873-ESM, Single Unit Configuration
Installation and Adjustment Instructions

2
Content
Overview......................................................4
Terms and functions...................................6
Installation and commissioning .............. 10
Connection diagram ......................................11
Required settings...........................................12
Further basic settings ....................................12
User interface............................................ 14
Settings...................................................... 21
Troubleshooting........................................ 31
Technical data........................................... 37
Available accessories............................... 40
Important note:
This documentation only contains information
related to the Ice and Snow Detector 1873 in the
“Single Unit” configuration.
For the “System” and “Multi Channel” configu-
rations, refer to the complete documentation
“Ice and Snow Detector 1873-ESM and 1875-
ESM” (ME-1873~5-ESM-EN).
Safety instructions
Always observe the attached safety instructions and
the general regulations for electrical installation dur-
ing installation and operation of the device!

3
Scope of delivery
Ice and Snow Detector
1873-ESM
Installation and Adjustment In-
structions:
Ice and Snow Detector 1873,
Single Unit Configuration
Safety instructions
tekmar pencil
(Rubber end can be used to operate
the touch display)

4
Overview
Tekmar ice detection systems use their combi sen-
sors to measure temperature and moisture in
heated outdoor areas such as open spaces, roofs
and gutters. This means that they operate in a par-
ticularly energy-efficient way, since the heating is
only switched on when it is cold or if there is water,
ice or snow.
The 73 ice detection system is an all-round system
wherever it is necessary to keep an area free of ice
and snow: It is flexible, maintenance-free and inex-
pensive. It can be modularly extended to form a
multi-channel system and can be used in a cloud
environment or in building management systems.
All system 73 control devices are easy to install and
commission. They are characterised by intelligent
factory settings and a straightforward commission-
ing function. The sensors and the control units can
be freely combined so that the system can be opti-
mally adapted to the operating conditions. All con-
trol units are designed for one combi sensor and
one heating circuit.
Ice and Snow Detector 1873-ESM
The Ice and Snow Detector 1873 is a single-
channel device that can be used for all applications
in the field of ice and snow detection.
It is operated and adjusted via an illuminated touch
graphic display, which is also used to set the para-
meters of all the other devices in a system. A three-
level password protection is available for the multi-
lingual menu.
A comprehensive alarm management checks both
the internal device functions and those of the con-
nected sensors. Furthermore, the function of the
heating relay and a downstream contactor can be
monitored.
Sensors
The System 73 sensors use a measuring principle
based on the thermal capacity of the sensor surface
and the water on it, possibly in the form of ice or
snow. This measuring principle was developed by
tekmar and has already proven itself over many
years. Only one sensor is required to measure
moisture and temperature, making installation very
simple and cost-effective.
System 73 offers two types of sensors: The 3356
sensor is ideally suited for installation in open
spaces such as roads, walkways or staircases. The
3354 sensor can be mounted, for example, in
gutters and on roof surfaces thanks to its design

Overview
5
with axial cable connection. Both sensors are
characterised by a compact and robust design,
which is achieved by the casing made of high-
quality, corrosion-resistant brass and the microbe-
proof, longitudinally watertight cable.
The sensors can be used for a wide variety of re-
quirements due to the comprehensive range of
accessories for their installation and mounting. This
also optimises installation and maintenance costs.
Documentation
Other relevant documentation:
Safety instructions
I-187x-ESM-Sensor-EN,
summarised extract from M-MES-Sensorik
(Installation instructions for sensors of the T,
TF-E und TF-S systems, available in German
only)

6
Terms and functions
Ice detection channel
An ice detection channel is a unit consisting of a
heating circuit with its output relay, a combi sensor
and the associated evaluation logic.
Functions of an ice detection channel:
control and monitoring of one sensor and one
heating circuit
continuous temperature monitoring in the
heated area
activation of the moisture measurement if the
temperature falls below the activation tempera-
ture
start of the minimum heating time if the
moisture threshold is exceeded on the sensor
(alternatively triggered by an external signal at
the control input)
deactivation of the heating if the temperature
falls below the switch-off temperature (lower
temperature limit)
monitoring of the heating circuit output for inter-
ruptions in the heating circuit and internal faults
of the relay
Operating mode
The basic operation of an ice detection channel can
be selected via the operating mode.
Temp. Moisture
This is the normal operating mode of an ice de-
tection channel. In this mode the temperature
must first fall below the activation point, and a
sufficiently high moisture measurement then ac-
tivates the heating circuit.
Temperature
In the temperature mode, only the tem-
perature is measured but not the
moisture. The heating will be active if the tem-
perature of the heating area is below the activa-
tion temperature.
Emergency mode
In addition to the automatic activation of
the emergency mode, it can also be acti-
vated manually in the event of malfunctions
around the system. Also refer to the explana-
tions under "Emergency mode" on page 8.
Off
The ice detection channel is switched off.

Terms and functions
7
Activation temperature (upper temperature limit)
If the temperature of the combi sensor - and thus of
the heated area - falls below the defined activation
temperature, the moisture measurement will be ac-
tivated and, if necessary, the heating circuit will be
switched on. If the temperature rises above the ac-
tivation temperature, an activated heating circuit will
be switched off and the moisture measurement will
be deactivated.
Moisture threshold
The moisture threshold can be used to adjust the
sensor's sensitivity with regard to the detection of
water, ice or snow on the sensor. The moisture
threshold can be set within a range of 0.5 to 9.5.
Low values mean high sensitivity.
The basic setting for the moisture threshold should
be 1 to 2 points above the dry value indicated on
the sensor. If no information is available on the
sensor, a test measurement can be triggered via
the menu when the sensor is dry and the deter-
mined value can be used as the dry value.
If the system switches the heating system on too
early, i.e. if there is very little moisture or the sensor
is dry, the moisture threshold should be increased.
If the system switches on the heating system too
late, the moisture threshold should be reduced.
Note: If the moisture threshold is too low, the
heating system may be permanently activat-
ed during times when the temperature is below the
activation temperature. This can lead to an in-
creased energy consumption. In general: the lower
the moisture threshold, the higher the energy con-
sumption.
Moisture measurement
Below the activation temperature, the moisture
measurement is repeated at regular intervals until a
moisture value above the moisture threshold is de-
tected or until the activation temperature is exceed-
ed again. If moisture is detected, the heating circuit
switches on for the minimum heating time and the
moisture measurement is suspended. Only after the
minimum heating time has elapsed is the moisture
determined again at regular intervals. Depending on
the result of the moisture measurement, the heating
circuit remains switched on or is deactivated.

Terms and functions
8
The system automatically optimises the duration of
a measuring cycle depending on the sensor type
and temperature.
Switch-off temperature (lower temperature limit)
In addition to the activation temperature, there is
also a lower temperature limit (the switch-off tem-
perature), below which the moisture measurement
and, if necessary, the heating are deactivated
again.
At very low outside temperatures, dripping conden-
sation no longer occurs in roof areas and snowfall is
no longer to be expected in open spaces. (If snow
falls, it will be dry, light and not slippery. Since in
this case the heating capacity is often not sufficient
to completely defrost the surface and it would only
be partially thawed instead, the risk of slipperiness
would be rather increased by switching on the heat-
ing system.)
Minimum heating time
If moisture above the moisture threshold is detected
after the temperature has fallen below the activation
temperature, the minimum heating time starts,
which ensures that the heated area is definitely de-
frosted. During the minimum heating time, no fur-
ther moisture measurement takes place.
An external button on input A, which is switched to
L, can be used to manually activate the defined
minimum heating time. When the button is pressed
once, the heating is switched on for the duration of
the minimum heating time.
Follow up time
After the monitored area has thawed and dried with
the help of the heating, i.e. when the combi sensor
no longer detects moisture, a follow up time can be
activated. In the event that the combi sensor cannot
be optimally positioned, the follow up time can be
used to ensure that any ice and snow residues are
also defrosted, e.g. in shaded areas.
Emergency mode
In the emergency mode the heating circuit output is
activated with a PWM (pulse width modulation) be-
haviour (adjustable interval time and duty cycle).
The emergency mode can either be activated man-
ually via the operating mode or automatically if
there is a temperature error in the combi sensor.

Terms and functions
9
In case of an error in the combi sensor additionally
an alarm will be triggered. If only the moisture unit
is affected by the sensor error, the emergency
mode will only be activated if the temperature is
below the activation temperature. If the temperature
unit is also defective, the emergency mode will be
activated independently of the outdoor temperature,
but only if this has been explicitly enabled in the
menu.
Note: The emergency mode should only be
activated if the alarm can be registered cen-
trally. An unnoticed emergency mode can possibly
lead to extreme energy consumption.
Heating circuit monitoring
The heating circuit connected to the heating circuit
relay is monitored for interruptions and the heating
relay itself for malfunctions. The heating circuit is
monitored when switched off. An interruption of the
circuit results in an alarm message.
Note 1: When using a contactor to increase the
switching capacity, only the contactor is monitored,
not the heating circuit connected to it.
Note 2: The switching output for relay R1/R2 must
be operated at 230 V to detect a switching output
error. When using a lower voltage (e.g. 24 V DC),
this function is not guaranteed and an error mes-
sage may occur.
Alarm management
The alarm management of the 1873 monitors the
sensor and heating circuit output for fault condi-
tions. A detected error is reported via the display
and the alarm relay.
Functions of alarm management:
monitoring of the ice and snow detector, the
sensor and the heating circuit output
adjustable alarm delay
forwarding of an alarm via the alarm relay
Alarm relay
The alarm relay is designed as a change-over con-
tact and can therefore be used for both open-circuit
and closed-circuit alarm circuits. By inverting the
alarm relay in the menu, a power failure can also be
reported (alarm inverted and signal loop via the
normally open/change-over contact).
Due to its insulation, the alarm relay can be used
for both mains voltage and SELV circuits.

10
Installation and commissioning
Proper use
The device must only be used for the control
of electric and water-operated heating
systems. It has to be installed in an electric distribu-
tor (fuse box or control cabinet) and connected to
the existing heating system. When doing so, it is
absolutely necessary to observe all Technical data.
Any different or improper use of the device may
cause defects in the device and/or life-threatening
states and situations. Additionally all guarantee
claims are forfeited in such a case.
Installation procedure
Only qualified personnel (electrician or
similar qualification) may install the device.
The relevant engineering practices and the
enclosed safety instructions must be observed!
Disconnect the control cabinet before installation.
Mount the device on a 35 mm mounting rail in a
subdistribution unit or another adequate housing.
Wire it according to the following illustration.
Protection against contact according to protection
class II is guaranteed by the following measures:
Installation in small distribution board according to
DIN 57603/VDE 0603 (e.g. distributor of the N-
system)
or
DIN 57659/VDE 0659
The regulations according to VDE 0100 must be
observed!
For the use of the unit, an on-site fuse pro-
tection by means of (a) miniature circuit
breaker(s) is mandatory. No additional fuse
protection is required for the alarm relay if it
is connected to a low voltage of up to 30 V
maximum. Parameters for fuse protection
can be found in the technical data.

Installation and commissioning
11
Connection diagram
1873-ESM
Note:
The “TGN” and “Weather sensor” connections are
not used if the 1873 is operated as a Single Unit.
In the “System” and “Multi Channel” configurations
the TGN bus is used to connect the 1873 with the
other devices in the system. The weather sensor is
used to gather information on the outside tempera-
ture for the base temperature and the pre-heating
modes.
For further information, refer to the complete docu-
mentation for the 1873-ESM and 1875-ESM (ME-
1873~5-ESM-EN).

Installation and commissioning
12
Required settings
When the device is started for the first time, a start
screen is displayed in which the menu language
must be selected. The default language is German,
which must be confirmed or changed.
Menu → Installer → Startup →
During initial startup, all parameters under the menu
item mentioned above must be set. These are:
Application
The application must be set to “Single Unit”.
For information about the “System” and “Multi
Channel” applications, refer to refer to the
complete documentation for the 1873-ESM
and 1875-ESM.
Sensor type (Single Unit, System)
The factory setting for the sensor type is "to be
defined”. Select the sensor type according to
the connected sensor. For further information
see page 25.
Further basic settings
Moisture threshold
Menu → Installer →
It should be checked whether the factory-set
moisture threshold matches the sensor used and its
environment. If no dry value is indicated on the
sensor, it can be determined with the help of a test
measurement:
1. The sensor must be dry.
2. Start a test measurement.
Service → ISD channel →
Start moisture measurement?
3. Add 1.0 to 2.0 to the determined moisture value
depending on the desired sensitivity and set this
value as the moisture threshold.
Config. modules → Moisture threshold
Also refer to Moisture threshold, page 7.
Minimum heating time
Operation
Adjustment of the minimum heating time for the ice
detector or the selected ice detection channel. Also
refer to Minimum heating time, page 8.

Installation and commissioning
13
Upper temperature limit
Operation
Adjustment of the upper temperature limit valid for
the ice detector or the selected ice detection chan-
nel. Also refer to Activation temperature, page 7.
Password protection
Menu → Information → Set passwords
If required, password protection can be set for
different menu levels. For further information refer
to page 30.
Idle display
line 1: channel state
line 2: temperature
line 3: moisture value
line 4: remaining heating time
line 5: error code
line 6: device type, menu button

Installation and commissioning
14
Connection of a downstream building control
system
It is intended to connect the heating circuit to a load
contactor or directly to the relay output of the ice
and snow detector. If, however, it is connected to a
relay interface module, a reliable function cannot be
guaranteed. This unintended application does not
always work reliably.
tekmar has, with no obligation, developed and test-
ed a solution for a correct function, also in connec-
tion with a recommended relay interface module for
connection to a building management system:
When using relay interface modules with the 1873-
ESM ice and snow detector, a malfunction of the
heating circuit monitoring can occur under certain
circumstances due to the design. This leads to a
faulty evaluation of the heating circuit or a malfunc-
tion of the connected relay interface modules. The
faulty evaluation can result in an unintentional
alarm. However, it would be more serious if the
heating circuit(s) were unintentionally activated,
which would lead to increased power consumption.
This kind of relay is normally only used in case of a
downstream building management system.
For the recommended relay interface modules,
proper function is only ensured if a base load ele-
ment is connected in parallel with the relay interface
module. In addition, the heating circuit monitoring
function (menu item Monitoring heating output
active) of all channels with a connected relay inter-
face module must be deactivated in this case.
Recommended components:
Relay interface module
Manu-
facturer
Article
Type
Finder
38.51 230V (Series 38)
1 x 6 A
Finder
48.52 230V (Series 48)
2 x 8 A
Finder
49.72 230V (Series 49)
2 x 8 A
Base load device
Eltako
EAN 4010312900970

Installation and commissioning
15

16
User interface
Touch display with softkey buttons
The touch display of the 1873 may be operated by
using up to four softkeys at the bottom of the
screen, pressing them either with the finger or the
rubber end of a pencil. The rest of the display does
not have a touch function. The following table
shows the possible functions of the softkeys.
After pressing the Menu button several menu items
are available.
The plus and minus buttons (+ and -) as well as the
arrow keys (> and <) have an auto-repeat function
in case the buttons are pressed for a longer time.
If the menu does not receive an answer to a data
request, the display will show the character string
"~~~" (3x tilde) instead of the parameter value.
When the device is taken into use for the first time,
the menu language (e.g. German or English) needs
to be selected. For further information refer to page
24.
Menu
launch menu
>>
next menu level
<<
one menu level back
>
next (to select one of several parame-
ters)
<
back (to select one of several param-
eters)

one line down

one line up
+
increase value
-
decrease value
Chng
change
OK
confirm
Esc
escape
Add
add entry
Del
delete entry
Edit
edit entry
Act
activate entry
0..9
numeric keypad

delete character (numeric keypad)
confirm entry (numeric keypad)

User interface
17
Menu structure
The individual menu items are explained in detail in
the chapters Settings and Operation. The menu
items under Menu → Installer are reserved for the
qualified installation technician. Some settings
appear under several menu items because this will
save time jumping back and forth in different menu
levels during installation. The menu items under
Installer → Startup can, for example, also be found
under Installer → Config. modules.
Numeric keypad
Several values can be entered via a numeric key-
pad. In this case the display's touch function is ex-
tended to all keys of the numeric keypad.

User interface
18
Menu
Level 1
Level 2
Level 3
Level 4
Page
Operation
Operating mode
21
Upper temperature limit
21
Moisture threshold
21
Minimum heating time
22
Start minimum heating
time?
22
Information
Channel state
22
Temperature moisture area
22
Last moisture measure-
ment
23
Remaining heating time
23
Operating time
23
Energy consumption
23
Device data
Serial number
23
Version
24
Set passwords
Set level 1
Set password for level 1
24
Set level 2
Set password for level 2
Set level 3
Set password for level 3
Setup
Language
24
Display
Contrast
24
Brightness menu
24
Brightness idle
24

User interface
19
Installer
Startup
Application
25
Sensor type
25
Information
Channel state
22
Error code
25
Temperature heating area
22
Last moisture measure-
ment
23
Remaining heating time
23
Remaining inhibition time
moisture
25
Operating time
23
Operating time total
26
Energy consumption
23
Energy consumption total
26
Device data
Serial number
23
Version
24
Config. modules
Operating mode
21
Sensor type
25
Upper temperature limit
21
Lower temperature limit
27
Moisture threshold
21
Minimum heating time
22
Follow up time
27
Heating output
27

User interface
20
PWM interval time
27
Emergency duty cycle
28
Alarm delay
26
Alarm relay inverted
26
Emergency mode with error
temperature
28
Blocking protection active
28
Operating time: Reset
counters
28
Service
ISD channel
Start minimum heating
time?
22
Stop heating?
29
Start moisture measure-
ment?
29
Sensor temperature
29
Last moisture measure-
ment
23
Remaining inhibition time
moisture
25
Restart
29
Factory settings
29