Danfoss AK-CC55 Multi Coil - System Utilities

1.
2.
3.
4.
The fan is OFF in the entire defrost sequence
The fan is ON during the entire defrost sequence except during fan delay state
The fan is ON during defrost state and is OFF in the rest of the defrost sequence
Like option 2, however the fans can be stopped if the selected defrost stop sensor exceeds a set fan stop limit
Real-time clock
The controller has a built-in real-time clock which can be used to start defrosts. This clock has a power reserve of
four days.
If the controller is equipped with data communication, the clock will automatically be updated from a Danfoss
system manager.
Coordinated defrost
There are two ways in which coordinated defrost can be arranged.
Figure 16: Coordinated defrost options
System manager
Max 10.
Danfoss 84B8268
Either with wire connections between the controllers or via data communication:
Wire connections
The digital input DI2 must be congured for coordinated defrost and wiring must be connected between the
relevant controllers. When one controller starts a defrost, all the other controllers will follow suit and likewise start a
defrost. After the defrost, the individual controllers will move into waiting position. When all are in waiting position
there will be a change-over to refrigeration.
Coordination via data communication
Here the system manager handles the coordination.
The controllers are gathered in defrosting groups and the system manager ensures that defrosting is started in the
group according to a weekly schedule.
When a controller has completed defrosting, it sends a message to the system manager and then goes into a
waiting position. When every controller in the group is in a waiting position, refrigeration is again permitted in all
the individual controllers.
Melt function
This function will prevent the air ow in the evaporator from being reduced by frost created by uninterrupted
operation for a long time.
The function is activated if the thermostat temperature has remained in the range between -5 °C and +10 °C for a
longer period than the set melting interval. The refrigeration will then be stopped during the set melting period.
The frost will be melted so that the air ow and hence the evaporator’s capacity will be greatly improved.
Rail heat
It is possible to pulse-control the power to the rail heat in order to save energy. Pulse control can either be
controlled according to day/night load or dew point.
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AK-CC55 Multi Coil