Miscellaneous - Danfoss AK-CC 750A User Manual

Miscellaneous

Alarm priorities
The different alarms that can be generated by the controller can
be given a priority.
"priority" will activate the alarm relay if it has been so defined. The
alarms are entered in the alarm log and also transmitted to the
data communication if connected.
The "Log only" priority will as mentioned only be entered in the
alarm log.
Setting Log Selection Alarm relay
Non High
High X X
Medium X
Low X
Log Only X
Disabled
Sensor correction
The input signal from all connected sensors can be corrected. A
correction will only be necessary if the sensor cable is long and has
a small cross-sectional area. All displays and functions will reflect
the corrected value.
Clock function
The controller contains a clock function, that can be used together
with schedules for defrost and day/night operation.
In the event of a power failure, the time setting will be remem-
bered for at least 12 hours
If the controller is linked up to a System Manager via the data com-
munication, the System Manager will reset the clock.
Signals via data communication
The controller contains a number of functions that can be acti-
vated/overridden by the network's system unit:
Night operation
The day/night operation of the individual controllers can be con-
trolled from a central weekly schedule in the system unit.
Interruption of injection
The system unit can ensure that all appliance and room controllers
force-close their valves if all compressors in the belonging central
plant stop due to operation breakdowns and are prevented from
starting again.
Light control
In appliance controllers the light can be controlled via a central
weekly schedule in the system unit.
Coordinated defrost
Several appliance controllers can be grouped in the system unit
so that they will start a defrost at the same time and subsequently
start up after defrost at the same time.
Adaptive defrosting
By using the "Adaptive Defrosting" function the controller must re-
ceive a condensing pressure signal Pc. This signal must be received
from the System Manager.
Optimization of suction pressure
The appliance/room controllers can supply the necessary informa-
tion to the system unit so that it can optimise the suction pressure
based on the appliance with the heaviest load.
92
Grid AKM-
work
Low - Mid- Low -
dle High
X X
X X X
X X X
RS8HP102 © Danfoss 2018-09
Forced refrigeration
The controller will undertake refrigeration when this signal is
received. Refrigeration will continue until the signal is removed.
The function will ignore the thermostat function, but forced
cooling will be stopped if there is a low temperature alarm. (If a
setting means that forced cooling and defrosting are required at
the same time, defrosting will have the higher priority.)
Display signal
dest.
1
2
3
The air temperatures measured at the evaporator can be read from
a display. This display must be of display type EKA 163B or EKA
164B. The display is normally mounted on the appliance so that
the customer can see the air temperature. Up to four displays per
controller can be fitted.
Connection is effected by means of wires with plug connectors.
The display can be placed on an appliance front, for example.
When a display with operating buttons is selected, the unit can be
operated with ease by means of a menu system as well as display-
ing temperatures and operating situations.
Display signal
Temperature display can be selected for a product sensor, or
alternatively a weighted condition between air sensors S3 and S4.
Setting is expressed as a percentage of the S4 signal.
The display is independent of the thermostat function.
An Offset can be set for the display.
Values are displayed by means of three digits, and one setting
allows you
to decide whether the temperature is to be displayed in °C or °F.
LEDs on the front
The LEDs will come on when the associated relay is activated:
2nd LED = refrigeration
3rd LED = defrost
4th LED = ventilator operational
The LEDs will flash when an alarm has been triggered.
In this situation, you can call up the error code on the display by
briefly pressing the top button. At the same time, any alarm relays
will be deactivated.
The buttons
When you want to change a setting, the top and bottom buttons
will give a higher or a lower value depending on which button
you press. Before you can change the value, you must access the
menu. This is done by holding down the top button for a couple
of seconds; this takes you into the list of parameter codes. Find the
parameter code you want to change, then press the centre but-
ton to display the parameter value. When you have changed this
value, save the new value by pressing the centre button again
Examples:
Setting a menu
1. Press the top button to display a parameter
2. Press the top or bottom button and find the parameter you
want to set
3. Press the centre button to display the value
AK-CC 750A