Danfoss ADAP-KOOL AK-CT 200A, ADAP-KOOL AK-CT 450A User Manual
User guide
Controller tray for refrigeration
appliance control with TEV
AK-CT 200A + AK-CT 450A
ADAP-KOOL® Refrigeration control systems
AK-CT 450A
Introduction
Application
Complete refrigeration appliance control with great exibility to
adapt to all types of refrigeration appliances and cold storage
rooms.
• For refrigeration with brine
• For use with a thermostatic expansion valve (TEV)
Advantages
• Optimised for installation by manufacturer
• Electricity-controlled and voltage controlled relay connections
• Loads requiring electricity can be connected directly
• Overcurrent limitation
• Energy optimisation of the whole refrigeration appliance
• One controller for several dierent refrigeration appliances
• Quick set-up with predened settings
• Built-in data communication
• Built-in clock function with power reserve
Principle
The temperature in the appliance is registered by one or two
temperature sensors which are located in the air ow before the
evaporator (S3) or after the evaporator (S4) respectively.
A setting for thermostat, alarm thermostat and display reading
determines the inuence the two sensor values should have for
each individual function.
In addition product sensor S6, which can be optionally placed in
the appliance, can be used to register the temperature near the
required product in a certain place within the appliance.
The temperature of the evaporator is registered with the S5 sensor
which can be used as a defrosting sensor.
In addition to the output for the solenoid valve type EVR the controller has 9 relay outputs which are dened by the use selected –
the individual usage options are described in detail on page 12
Functions
• Day/night thermostat with ON/OFF or modulating principle
• Product sensor S6 with separate alarm limits
• Switch between thermostat settings via digital input
• Start of defrost via schedule, digital input or network
• Natural, electric, hot gas defrost or brine defrost
• Stop of defrost on time and/or temperature
• Coordination of defrosting among several controls
• Pulsing of fans when thermostat is satised
• Case cleaning function for documentation of HACCP procedure
• Rail heat control via day/night load or dew point
• Door function
• Control of two compressors
• Control of night blinds
• Light control
• Heat thermostat
• Integrated MODBUS communication with the option of
mounting a LonWorks communication card
Contents
Introduction ....................................................................................................... 2
Operation ............................................................................................................ 4
Applications .....................................................................................................12
Connections ..................................................................................................... 17
Appliance examples
Survey of functions ........................................................................................ 19
Operation .......................................................................................................... 32
Menu survey .....................................................................................................33
Ordering ............................................................................................................39
Data ..................................................................................................................... 40
2 User Guide RS8GR602 © Danfoss 2016-10 AK-CT 450A
Applications
Here is an overview of the controller’s usage options.
• Standard appliance or cooling room with one valve,
one evaporator and one cooling section.
• Refrigeration appliance with one valve, two evaporators
and two cooling sections (each with its own temperaturemeasuring function).
• Refrigeration device with one valve, one evaporator and
two cooling sections.
A setting will congure input and outputs so that the controller’s
operation interface is directed at the selected application.
The current settings for the respective uses can be found
on page 34.
Installation benets
The controller is designed to provide a number of advantages
when installed by the refrigeration appliance manufacturer,
such as:
High relay load
Load connection/disconnection is controlled by a voltage
measurement and a current measurement, so that the relay’s
switch function can operate under optimal conditions.
The controller can then connect loads of up to 16 A, without
the use of auxiliary relays.
Spring clamps
All cable connections are made using plugs with spring switches.
This allows for fast and easy installation.
Parallel power point
Several of the outlets have double or triple connections points,
so the use of external loop clips is not usually necessary.
Structure of the controller
The controller consists of hardware type AK-CT 200A and a
software identity code AK-CT 450A.
This software identity code is delivered in a separate plug
and must be placed in an RJ45 plug in the hardware. It is rst
necessary to mount the plug when conguring the controller.
AK-CT 450A User Guide RS8GR602 © Danfoss 2016-10 3
Operation
Cooling
Regulation can be performed on the basis of the following principles:
Direct expansion
The temperature is controlled either through the starting/stopping of a compressor or through the opening/closing of a solenoid valve in the liquid line.
Brine
Here, the temperature is controlled by opening/closing a solenoid
valve/motor valve in the brine supply.
Temperature control
The temperature in the appliance is registered by one or two
temperature sensors which are located in the air ow before the
evaporator (S3) or after the evaporator (S4) respectively. A setting
for the thermostat, alarm thermostat and display reading determines how much the two sensor values should inuence each
individual function, e.g. 50% will produce an equal value from
both sensors.
Various weightings can be set for day and night operation.
The actual temperature control can take place in two ways: as an
ordinary ON/OFF regulation with a dierential, or as a modulating control where the temperature variation will not be nearly as
great as in ON/OFF control. There is however a limit to the use of
a modulating control as it can only be used in DX central plant or
brine system.
In principle, regulation in this system is the same as described
above, but is now performed with a PI function. This results in
reduced uctuation of the regulated air temperature with stable
loads, giving a more constant air humidity.
The function gives a constant temperature regulation with a temperature value, which lies half-way between the on and o values
of the thermostat.
The operating parameters of the PI regulation are automatically
optimised via the preset on and o values and the degree of
opening of the valve.
The dierential aects the amplication of the regulator and can
therefore not be set to less than 2K in order to ensure regulation
stability.
In a decentralised plant the thermostat function with ON/OFF
control should be selected.
In a central plant the thermostat function may either be selected
for ON/OFF control or modulating control.
Temperature monitoring
Just as is possible for the thermostat, the alarm monitoring can
be set with a weighting between S3 and S4 so that you can decide
how much the two sensor values should inuence the alarm
monitoring. Minimum and maximum limits can be set for alarm
temperature and time delays. A longer time delay can be set
for high temperature alarms after defrosting, appliance cleaning
or start-up.
On /O
Modulating
4 User Guide RS8GR602 © Danfoss 2016-10 AK-CT 450A
Thermostat bands
Thermostat bands can be used benecially for appliances where
dierent product types are stored which require dierent temperature conditions. It is possible to change between the two
dierent thermostat bands via a contact signal on a digital input.
Separate thermostat and alarm limits can be set for each thermostat band – also for the product sensor.
Night setback of thermostat value
In refrigeration appliances there may be big load dierences
between the shop’s opening and closing hours, especially if night
lids/blinds are used. The thermostat reference may be raised here
without it having any eect on the product temperature.
Change-over between day and night operation can take place,
as follows:
• via an external switch signal.
• via a signal from the data communication system.
Product sensor
A separate product sensor S6, which may be placed in the
appliance, can also be used and which can register and monitor
the temperature in the warmest part of the appliance. There are
separate alarm limits and time delays for the product sensor.
Appliance cleaning
This function makes it easy for the shop’s sta to carry out a
cleaning of the appliance according to a standard procedure.
Appliance cleaning is activated via a signal – as a rule via a key
switch placed on the appliance.
Appliance cleaning is carried out via three phases:
1 - at the rst activation the refrigeration is stopped, but the fans
keep on operating in order to defrost the evaporators. ”Fan” is
shown on the display.
2 - at the second activation the fans are also stopped and the
appliance can now be cleaned. ”OFF” is shown on the display.
3 - At the third activation refrigeration is recommenced.
The display will show the actual appliance temperature,
(o97 setting).
When appliance cleaning is activated a cleaning alarm is
transmitted to the normal alarm recipient. A later processing
of these alarms will document that the appliance has been
cleaned as often as planned.
Alarm monitoring
There are no temperature alarms during appliance cleaning.
Appliance shut-down
The function closes the solenoid valve and all outputs are
switched o.
The cooling appliance is stopped like the “Main switch”, but this
happens without an “A45 standby alarm”.
The function can be enabled by a switch on the DI input or via
a setting through data communication.
- + + °C
1 ÷ + Fan
2 ÷ ÷ O
3 + + °C
AK-CT 450A User Guide RS8GR602 © Danfoss 2016-10 5
Defrost
Depending on the application you may choose between the
following defrost methods:
Electric: The heating element is activated
Hotgas: Here the solenoid valves are controlled so that the
hotgas can ow through the evaporator
Brine: Here, the solenoid/motor valve is opened on the supply
pipe, so that hot brine can be fed through.
Natural: Here the fans are kept operating during the defrost
Defrost sequence
1) Pump down
2) Defrost
3) Waiting position after defrost
4) Draining (drain delay. Hotgas only)
5) Drip o
6) Delay of fan
Hot gas defrost (application 7 only)
This type of connection can be used on systems with hotgas
defrost, but only in small systems in, say, supermarkets – the
functional content has not been adapted to systems with large
charges.
Must not be used together with PMLX and GPLX valves, unless
a time delay relay is installed, which ensures that the PMLX/GPLX
valve is closed completely before the hotgas is turned on.
Drip tray heating element
It is possible to control a heating element in the drip tray for
hot gas defrosting. When defrosting is commenced, the heating
element is activated. The heating element remains activated until
a set time after defrosting has ended by time or temperature.
Start of defrost
A defrost can be started in dierent ways
Interval: Defrost is started at xed time intervals, say, every
eighth hour. An interval must ALWAYS be set to
a "higher" value than the period set between two
defrostings when a schedule or network signal is used.
Refrigeration time: Defrost is started at xed refrigeration time
intervals, in other words, a low need for refrigeration will
”postpone” the defrost
Schedule: Here defrost can be started at xed times of the
day and night. However, max. 6 times
Contact: Defrost is started with a contact signal on a digital input
Network: The signal for defrost is received from a system unit
via the data communication
Manual: An extra defrost can be activated from the controller’s
lower-most button
All the mentioned methods can be used at random – if just of
them is activated a defrost will be started.
Hot gas application
Stop of defrost
Defrosting can be stopped by either:
• Time
• Temperature (with time as safety).
6 User Guide RS8GR602 © Danfoss 2016-10 AK-CT 450A
Coordinated defrost
There are two ways in which coordinated defrost can be arranged.
Either with wire connections between the controllers or via data
communication
Wire connections
The digital input DI2 is connected between the current 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 unit handles the coordination.
The controllers are gathered in defrosting groups and the system
unit 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 unit 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.
Defrost based on refrigeration time
When the aggregate refrigeration time has passed a xed time,
a defrost will be started.
Max. 10 pcs.
System manager
Min. time between defrosts
There is a 2 hours minimum time between defrosts.
This avoids that planned defrosts in accordance with the weekly
schedule are carried out immediately after a defrost on demand
has been carried out. The time applies from when a Defrost based
on refrigeration time has been completed to when a planned
defrost is again permitted. Defrost based on refrigeration time will
not start defrosting with a shorter interval than the 2 hours either.
Melting function
This function will stop 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.
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 more than 24
hours.
If the controller is equipped with data communication, the clock
will automatically be updated from the system unit.
AK-CT 450A User Guide RS8GR602 © Danfoss 2016-10 7
Control of two compressors (application 8)
The two compressors must be of the same size.
When the controller demands refrigeration it will rst cut in
the compressor with the shortest operating time. After the time
delay the second compressor will be cut in.
When the temperature has dropped to ”the middle of the
dierential”, the compressor with the longest operation time
will be cut out.
The running compressor will continue until the temperature
has reached the cutout value. Then it will cut out. When the
temperature again reaches the middle of the dierential,
a compressor will again be started.
If one compressor cannot maintain the temperature within the
dierential, the second compressor will also be started.
If one of the compressors has run on its own for two hours,
the compressors will be changed over so that operational time
is balanced.
The two compressors must be of a type that can start up against
a high pressure.
The compressors’s settings for ”Min On time” and ”Min O time”
will always have top priority during normal regulation. But if one
of the override functions is activated, the ”Min On time” will be
disregarded.
Railheat
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.
Pulse control according to day and night
Various ON periods can be set for day and night operation.
A period time is set as well as the percentage part of the period
in which the rail heat is ON.
Pulse control according to dew point
In order to use this function a system manager of the type AK-SM
is required which can measure dew point and distribute the
current dew point to the appliance controllers. For this the rail
heat’s ON period is controlled from the current dew point.
Two dew point values are set in the appliance control:
• One where the eect must be max. i.e.100%. (o87)
• One where the eect must be min. (o86).
At a dew point which is equal to or lower than the value in 086,
the eect 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
The rail heating will be active during defrosting (as selected
in setting d27).
Rail heat
Dew point
8 User Guide RS8GR602 © Danfoss 2016-10 AK-CT 450A
Fan
Pulse control
To obtain energy savings it is possible to pulse control the power
supply to the fans at the evaporators.
Pulse control can be accomplished in one of the following ways:
- during the thermostat’s cutout period (cold room)
- during night operation and during the thermostat’s cutout
period (appliance with night lid)
A period of time is set as well as the percentage of this period of
time where the fans have to be operating.
Cutout 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
power supply 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.
Fan pause
When the setting P65 is set to a value greater than 0, the fans will
stop while the night blind is rolling down.
Eco-mode
When the night blind is down, the fan speed can be reduced.
Eco-mode is not allowed if the heating function has been
activated.
When Eco-mode is enabled, relay DO8 will be activated.
Period time
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 dened in more than one way:
- The light is controlled via a signal from a door contact.
The light will remain on for 2 minutes after the door has been
shut.
- The light is controlled via the day/night function.
- 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.
• Two signals, both of which can be on before the light goes on.
One can be a DI contact signal at the appliance (fx DI3) and the
other can be via data communication or a voltage signal.
Voltage signal must be activated on DI7.
The light is switched o when "r12" (Main switch) is set to o
(see o98).
The light is switched o when the appliance cleaning function
is activated.
If an override of the light is desired, this can be done via pulse
pressure on a DI input + setting = 19.
Extra light (light 2)
Light 2 can also be activated by one DI input, e.g. DI4.
It can also be controlled with two signals. For two signals,
the second signal must be sent with a voltage signal on DI8.
Light 1
controlled by
DI7
and fx DI3.
Light 2
(extra light)
controlled by
DI8 and fx DI4.
Override of light 1
AK-CT 450A User Guide RS8GR602 © Danfoss 2016-10 9
Night blind
Motorised night blind 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 opens
and when the light is switched o, the night blinds close again.
When the night blinds are closed, it is possible to open them
using a pulse signal on the digital input. If this input is activated,
the night blinds will open and the refrigeration appliance can
be lled with new products. If the input is activated again,
the blinds close again.
If the activation is omitted, the blind will close automatically
when the delay time expires. A setting is used to dene whether
the light is to be on or o when the night blind is up.
When the night blind function is used, the thermostat function
can control with dierent weighting between the S3 and S4
sensors. A weighting during day operation and another when
the blind is closed.
A night blind is open when the appliance cleaning function
is activated.
A setting can dene that the night blind is open when "r12"
(Main switch) is set to o (see o98).
Digital inputs
There are six digital inputs with contact function and two digital
inputs with high voltage signal.
They can be used for the following functions:
- Retransmission of contacts position via data communication
- Door contact function with alarm
- Starting or cancelling a defrost cycle
- Main switch - start/stop of cooling
- Night setback
- Thermostat bands switch
- General alarm monitoring
- Case cleaning
- Forced cooling
- Override of night blinds
- Coordinated defrost (DI2 only)
- Forced closing of valve
- Appliance shutdown
- Light, Extra light, Override light
Forced closing
The solenoid valve can be closed with an external signal
( "Forced closing").
If a defrost cycle is in progress, the forced closing status will not
be re-established until the defrost is completed. Otherwise,
the defrost cycle will be stopped immediately when the signal
is received. The function can be dened in o90. The signal can
be received from the DI3-input or via the data communication.
During a forced closing the fans can be dened to be stopped
or in operation.
Door contact
The door contact function can via the digital inputs be dened
for two dierent applications:
Alarm monitoring
The controller monitors the door contact and delivers an alarm
message if the door has been opened for a longer period than
the set alarm delay.
Alarm monitoring and stop of refrigeration
When the door is opened the refrigeration is stopped, i.e. the
injection, the compressor and the fan are stopped and light
switch on.
If the door remains open for a longer time than the set restart
time, refrigeration will be resumed. This will ensure that
refrigeration is maintained even if the door is left open or
if the door contact should be defective. If the door remains
open for a longer period than the set alarm delay an alarm
will also be triggered.
10 User Guide RS8GR602 © Danfoss 2016-10 AK-CT 450A
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 o is set as an oset value
under the current cutout limit for the refrigeration thermostat.
This ensures that refrigeration and heating do not occur
simultaneously. The dierence 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.
Data communication
The controller has xed built-in MODBUS data communication.
If there is a requirement for a dierent 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).
Refrigeration
Neutral zone
Heat
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.)
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
AK-CT 450A User Guide RS8GR602 © Danfoss 2016-10 11
Applications
Here is a survey of the controller’s eld of application.
The applications are all adapted for commercial refrigeration
systems in the form of either refrigeration appliances or cold
storage rooms.
A setting (o61) will dene the relay outputs so that the controller’s
interface will be targeted to the chosen application.
Control sensors and temperature monitoring function
S3 and S4 are temperature sensors. The application will determine
whether either one or the other or both sensors are to be used.
S3 is placed in the air ow before the evaporator. S4 after the
evaporator.
A percentage setting will determine how the control is to be
based.
If there are two cooling sections, S3b is used for section 2.
S5 is a defrost sensor and is placed on/in the ns of
the evaporator.
An S5B is also used when there are two evaporators, as well as
when there is a long, single evaporator.
S6 is a product sensor. S6B used when there are two sections.
Digital input
DI1 to DI6 is the on/o input that can be used, for example, for
one of the following functions: Door function, alarm function, defrost start, external main switch, nighttime operation, thermostat
reference switch, appliance cleaning, forced cooling, light, defrost
cancellation or defrost coordination.
DI7 and DI8 are 230 V inputs that can activate similar functions.
(For light function with two signals, the input is locked for
Light 1/Light 2.)
See the functions in the respective settings o02, o37, o84, etc.
Control of night blinds
Night blinds follow the status of the light function – when the
light is switched on, the night blinds are up and when the light is
switched o, the night blinds are down. In addition a digital input
provides the option of forced opening of the blinds so that the
appliance can be lled with products.
Heat thermostat
The heat thermostat is typically used if the temperature is to be
controlled within narrower limits, e.g. for cutting rooms, etc. The
heating thermostat can be set as a dierence in relation to the
cutout limit for the refrigeration thermostat so that simultaneous
refrigeration and heating are avoided.
Varmelegemet tilsluttes DO2 udgangen, og vil være aktiv under
The heating element is connected to the DO2 outlet and will be
active during regulation when the temperature becomes too low.
The outlet will also be active if electric defrost is required.
The function is dened by setting the delay time r63 lower than
the max. value.
The function cannot be used together with hot gas defrosting.
Function Input/Settings menu Setting
DI1 DI2 DI3 DI4 DI5 DI6 DI7 DI8
o02 o37 o84 P55 P56 P57 P58 P59
Not used + + + + + + + + 0
Follows DI’s status + + + + + + + + 1
Door contact function + + + + + + + + 2
Door alarm + + + + + + + + 3
Start defrost + + + + + + + + 4
Main switch + + + + + + + + 5
Nighttime operation + + + + + + + + 6
Thermostat band + + + + + + + + 7
DI alarm when closed + +
No function + + + + + +
DI alarm when open + +
No function + + + + + +
Appliance cleaning + + + + + + + + 10
Forced cooling + + + + + + + + 11
Night blind + + + + + + + + 12
Coordinated defrost +
No function + + + + + + +
Forced close + + + + + + + + 14
Appliance shutdown + + + + + + + + 15
Light + + + + + + + + 16
Extra light + + + + + + + + 17
No defrost + + + + + + + + 18
Override light + + + + + + + + 19
Example
If DI1 is used to start a defrost cycle, o02 must be set to 4.
8
9
13
12 User Guide RS8GR602 © Danfoss 2016-10 AK-CT 450A
Loading...