During Defrosting; Fan - Pulse Control - Danfoss AK-CC55 User Manual

User Guide | Controller for appliance control, AK-CC55
• One where the effect must be min. (o86).
At a dew point which is equal to or lower than the value in 086,
the effect will be the value indicated in o88.
In the area between the two dew point values, the controller will
manage the power to be supplied to the rail heat.

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 lid)
(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.
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 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).
Eco operations (only with custom application)
Reduced fan speed is permitted when the night blind is down.
(Fan with changeover between two speeds).
Eco operation is not permitted if the heat function is activated.
Light function
The function can be used for controlling the light in a refrigeration
appliance or in a cold room. It can also be used for controlling a
motorised night blind.
The light function can be defined in several ways:
- the light is controlled via a signal from a door contact.
The light is kept on for a set time after the door has been closed.
- the light is controlled via the day/night function.
- the light is controlled via a DI input or remote light control from
system unit.
- the light is controlled via the data communication from a system
unit.
Here there are two operational options if data communication
should fail:
- The light can go ON.
- The light can stay in its current mode.
44 | BC308437742037en-000101
The light load must be connected to the NC terminals on the relay.
This ensures that the light remains on in the appliance if power to
the controller should fail.
A setting defines how light is controlled when regulation is
stopped via r12 Main switch = OFF (see o98). The light is switched
off when the appliance cleaning function is activated (only with
custom set-up and when light relay is configured).
Night blind
Motorised night blinds can be controlled automatically from
the controller. The night blinds will follow the status of the light
function. When the light is switched on, the night blinds open and
when the light is switched off, the night blinds close again. When
the night blinds are closed, it is possible to open them using a
switch signal on the digital input. If this pulse signal is activated,
the night blinds will open and the refrigeration appliance can be
filled with new products. If the pulse signal is activated again, the
blinds close again.
When the night blind function is used, the thermostat function
can control with different weighting between the S3 and S4
sensors. A weighting during day operation and another when the
blind is closed.
A night blind is opened when the appliance cleaning function is
activated.
A setting can define that the night blind is opened when "r12"
(Main switch) is set to off (see o98).
When the night blind rolls down, the fan will be stopped for the
set time. The night blind can thereby roll down to the correct posi-
tion.
Humidity control
The controller measures the humidity via a 0 – 10 V signal from a
humidity sensor. The humidity control works as a simple on/off
signal to a humidifier.
If the humidity gets below the set cut-in value, humidification is
started via a DO signal to a humidifier.
If the humidity increases to set cut-in value + differential
humidification is stopped.
Alarm at too low or too high humidity values after a set alarm
delay.
Option for disabling humidity control during defrost cycle.
If the measured air temperature used for the temperature control
is getting below 2 degrees Celsius, the humidification is disabled.
The air temperature must increase 1 degree Celsius in order to re-
enable humidification again.
© Danfoss | DCS (vt) | 2019.09