EM 524 89, EM 524 90 – Snow and ice detectors

The EM 524 89 snow and ice detector serves for switching-on heating cables heating outdoor surfaces (ramps, sidewalks, staircases, heliports, etc.) or rof drains (gutters, drains, conduits, roof parts). The EM 524 90 double detector is now also available. This regulator controls two indpendent circuits, thus fulfilling the function of two EM 524 89 regulators. It can be used for example to regulate two gutters on opposite sides (north and south) or gutters and an access road.

The switching process uses the values measured on several temperature and humidity sensors. The algorithm of the regulator evaluates the conditions for turning on. In the following table you will find the summary of sensors, that can be connected to the regulator. The regulator is positioned onto the DIN ledge in the switchgear and initiates the heating cables using the output relay either directly, or through a suitable contactor. A malfunction of the regulator or sensors is signalized by a contact of the second relay.


EM 524 89

EM 524 90 – Detektor sněhu a leduEM 524 90


  EM 524 89 EM 524 90
Supply voltage 230 V AC
Input ≤15 VA ≤25 VA
Housing IP 20
Installation onto the DIN ledge
Dimensions 106 x 90 x 58 mm 159 x 90 x 58 mm
Display 2 x 16 symbols
Control 3 buttons 4 buttons
Regimes surfaces, roofs
Range of temperature measurement -45 až +78°C
Range of humidity measurement  0 to 9 (relative data)
Inputs for all sensors
Heating relay startup contact 250 V AC/16 A startup contacts 2 relays 250 V AC/16 A
Alarm relay switching contact 250 V AC/2 A
ESF 524 001 / 011 heated humidity sensor for surfaces
TFF 524 002 / 012 not-heated humidity and temperature sensor for surfaces
ESD 524 003 heated humidity sensor for roof gutters
TFD 524 004 air temperature sensor



Gutter heating
Heating of outdoor surfaces


Documents for download
524 89 (de, gb) catalogue sheet
Manual 524 89 (cz)
Manual 524 89 (en)
Manual 524 89 (sk)
CE agreement declaration 524 89
524 90 (cz) catalogue sheet
Manual 524 90 (cz)
Manual 524 90 (de)

For the switching of simple gutter and outdoor surface heating systems, a simple device can be used - the DTR-E 3102 double bimetallic spatial thermostat. This thermostat initiates heating in a set range of outside temperatures, for example -7 to +5°C. In this range of outdoor temperatures, melting of snow and ice is most common, so during this time it is best to heat. Out of this extent (under -7°C and over +5°C), melting isn´t so frequent and heating isn´t necessary.

back to: Regulation for the heating of gutters and outdoor surfaces