AK-CT
450A
User
Guide RS8GR602 © Danfoss 2016-10
11
Data communication
The controller has fixed built-in MODBUS data communication.
If there is a requirement for a different form of data
communication, a Lon RS 485 module can be inserted in the
controller.
The connection must then be to terminal RS 485.
(To use a Lon RS 485 module and gateway type AKA 245
the module must be Version 6.20 or higher.)
It is not possible, however, to show all parameters available
in AK-CT 450A).
Important
All connections to the data communication MODBUS and RS 485
must comply with the requirements for data communication
cables. See literature: RC8AC.
Display
The controller has two plugs for a display. Here display type
EKA 163B or EKA 164B (max. length 15m) can be connected.
EKA 163B is a display for readings.
EKA 164B is both for readings and operation.
(It is not possible to connect a display to the Modbus terminals,
as in the other AK-CC 450 controllers.)
Refrigeration
Heat
Neutral zone
If there are two cooling sections,
the bottom plug will be the A
section and the top plug will be
the B section.
If there is one cooling section,
the displays will be the same for
both plugs.
Override
The controller contains a number of functions which can be used together with the override function in the master gateway/system
manager.
Function via data communication
Function in gateway/system manager
Used parameters in AK-CT 450A
Start of defrosting
Defrost control / Time schedule / Defrost group
--- Def start
Coordinated defrost
Defrost control / Defrost group
--- HoldAfterDef / - - - DefrostState
Prevent defrost start
--- Disable Def
Day/Night schedule
Day/Night control / Time schedule / Light zone
--- Night setback
Light control
Day/Night control / Time schedule
O39 light Remote
Forced closing
Forced Close / Injection ON / AKC ON
--- Forced cl.
Forced cooling
--- Forced cool
Rail heat link to dew point
/ Enhanced railheat
--- Dew point
P0 optimization
P0 Optimization
The controller supports P0 optimization
Heating function
The heating function is used to prevent the temperature
becoming too low, e.g. in a cutting room, etc. The limit for
when the heating function cuts off is set as an offset value
under the current cutout limit for the refrigeration thermostat.
This ensures that refrigeration and heating do not occur
simultaneously. The difference for the heating thermostat has
the same value as for the refrigeration thermostat. To prevent
that the heating thermostat cuts in during short-term drops
in air temperature a time delay can be set for when to change
from refrigeration to heating.
