Defrosting; Safety Circuit; Compressor Control; Maintenance - Dantherm CDF 10 Service Manual

4.3 Defrosting

If the temperature falls to below 20ºC the evaporator may start to ice up after a short time.
The defrosting function is activated when the evaporator sensor registers a temperature lower than 5ºC, after which
the control will let the unit operate in dehumidification mode for another 44 minutes. Then the fan is stopped, hot
refrigerant is bypassed the condenser and is finally led through the evaporator where it melts the ice. When the
evaporator sensor registers that the temperature is above 5ºC, the fan starts again.

4.4 Safety circuit

If the temperature on the condensor coil increases to a temperature of more than 55ºC (for example in case of fan
failure), the compressor is stopped automatically to avoid any damage. After 44 minutes the compressor starts
again automatically.
At room temperatures lower than 3°C and higher than 48°C the unit is automatically switched off to protect the
cooling plant against icing up or superheating. When the temperature is higher than 3°C or lower than 48°C the
dehumidifier will automatically start again. The temperature is registered by a sensor on the PCB.

4.5 Compressor control

At compressor start, the solenoid valve opens up for at least 10 sec. in order to relieve the pressure on the
compressor starting circuit.
Any stop of the unit – either caused by failing power connection, by the switch on the side of the unit, by the
hygrostat, or by the water tank's water stop function - will make the electronic control put off re-start for 45
seconds in order to protect the compressor from being switched on and off repeatedly.

5. Maintenance

The dehumidifier requires very little attention for trouble free running. All the necessary safety and control
functions have been built in. The fan motor and the compressor have permanent lubrication and require no
particular maintenance.

5.1 Cleaning of filter

Once a month the air inlet filter should be checked and cleaned if necessary. The front cover panel is removed and
the filter taken out. Clean the filter in tepid soapy water or if not badly soiled by vacuum cleaning.

5.2 Cleaning of the dehumidifier

Once a year the front cover panel should be removed in order to check the inside of the dehumidifier. If the
dehumidifier is dirty it should be cleaned by vacuum cleaning. The condenser in particular should be thoroughly
vacuumed. If the tube evaporator is badly soiled, it may be washed in tepid soapy water.
13