Defrosting 01.03.2020 10:03 01.03.2020 13:17

Defrosting gutters is done using electric heating cables (Raychem, etc.) controlled according to the outdoor temperature and precipitation, using temperature and humidity sensors placed in the gutter. When the outdoor temperature drops below the set value, and simultaneously there is indication of moisture in any state (water, snow, ice etc.), the heating cables are turned on. When the temperature rises above the set value, or the indication of humidity disappears, the heating is switched off (the heating cables are put out of operation).

The temperature sensor is located near the gutter and the humidity sensor is placed directly into the gutter, preferably near the drainpipe. If any state of humidity appears, the humidity sensor melts it via a 2 W heating resistor and transmits the signal. It is recommended that two moisture sensors are connected in parallel for better reliability, and if moisture appears on one of them, the system is put into operation.


The wiring example shows a heated sensor ESD 524 003 (Eberle) and an NTC temperature sensor (it can also be the NTC 12k or e.g. the TFD 524 004 - an NTC 10k sensor). The sensors can be connected to any input of the control system with an appropriate range (the humidity sensor is connected to the input for condensation measurement). The connection to the C-HM-0308M module is shown in the following figure.


Fig. 1. A wiring diagram – defrosting gutters


  1. Defrosting of areas and gutters can be combined, and both systems can be supplied from the same source.

  2. The relay heating output must be adjusted (strengthened) according to the actual switching power.