Figure 21: Rail heat control, dewpoint
Danf
oss
84B2729
o88
o86
100%
o87
During defrosting
During defrosting rail heat will be active, as selected in setting d27.
Fan
Pulse control
To obtain energy savings, it is possible to pulse control the power supply to the evaporator fans.
Pulse control can be accomplished in one of the following ways:
• during the thermostat’s cut-out period (cold room)
• during night operation and during the thermostat’s cut-out period (appliance with night blinds) (The function is
not actual when r14=2, i.e. modulating regulation).
A period of time is set as well as the percentage of this period of time where the fans have to be operating.
Figure 22: Fan cycle time
Cut-out of fans during plant breakdowns
If the refrigeration in a breakdown situation stops, the temperature in the cold room may rise quickly as a result of
the emission of heat from large fans. In order to prevent this situation, the controller can stop the fans if the
temperature at S5 exceeds a set limit value. The fans will start running again when the S5 temperature has dropped
2K below the set limit. (The function can also be used as a type of MOP function. Here the load on the compressors
is limited until the S5 temperature has fallen below the configured value).
Fan ECO operation (only custom set-up)
Fan ECO operation is used to reduce fan speed during night operation – typically on cabinets with night blinds.
The function is enabled when a relay has been configured for Fan ECO function in one of the applications with
custom set-up of relay functions.
The fan economy control (fan speed) is controlled via the two fan outputs:
• Fan output
• Fan Eco output
If the Fan output is activated, then the fan is running with 100% speed.
If the Fan ECO output is also activated, then the fan is running with reduced speed (typically 50%).
If both fan outputs are de-activated, then the fans are stopped.
© Danfoss | Climate Solutions | 2022.08
BC365212986197en-000201 | 19
AK-CC55 Compact