Danfoss EFIT 850, Инструкция по установке и эксплуатации, Страница: 33 / 36

User Manual
33
Ground system
The ground system is
fully automated . It gathers
information on moisture
and temperature via digital
sensors continuously . The
sensors are placed on stra-
tegic spots on the ground
area (for further informa-
tion on the sensor please refer to the sensor manual) . By combining measurements of
both moisture and temperature a reliable detection of the situation is achieved .
Hence it is known whether heating of the ground area is needed in order to avoid that
the ground area is covered by ice and snow .
Standby
The system is on standby awaiting need for heating . If the measured temperature is
below the chosen standby temperature the system will automatically heat the area in
order to maintain the standby temperature .
Melting (heating) will start when the two following conditions are fulfilled:
• Measured moisture is higher than the chosen limit for moisture.
• Measured temperature is lower than the chosen melting temperature
Temperature and moisture are measured continuously by the sensors .
Melting Ice and snow
As long as the measured temperature is lower than the chosen melting temperature
heating of the ground area will be on . When the measured temperature reaches the
chosen melting temperature and the measured moisture level is below the chosen
limit, the post-heating function will be activated . The post-heating function can be
disabled .
If moisture is detected on the ground area the system will continue to heat the area
in order to maintain the melting temperature . It is, however, important to understand
that even when the system is melting ice and snow it is not necessarily heating at all
times . The heating will be turned on and off in accordance with the measured tempera-
ture in order to maintain a constant melting temperature .
If the temperature rises more than 1 .5°C above the chosen melting temperature the
system will automatically stop heating the area irrespective of the moisture on the
area .
Appendix B
Standby
(No heating)
Melting
(Heating)
Post-heating
(Heating)
Standby
Mantaining standby
temperature
(Heating)
Temperature < Melting temperature
and
Moisture > Moisture limit
Moisture < Moisture limit
Temperature <
Standby temperature
Temperature >-
Standby temperature
Poa
t-hea
t time elapsed
Temper
atur
e >
M
elting
temper
atur
e + 1,5˚C