Danfoss AK-CC 460 User guide
User Guide
Controller for SemiPlugin appliance
AK-CC 460
www.danfoss.com
User Guide | Controller for SemiPlugin appliance, AK-CC 460
Contents
Introduction .........................................................................................................2
Applications .........................................................................................................3
Survey of functions ......................................................................................... 10
Operation ........................................................................................................... 21
Introduction
Application
Complete refrigeration appliance control for SemiPlugin
refrigeration appliances.
- Where condensation heat is removed using brine
- Flammable refrigerants supported
- The total amount of refrigerant can be distributed across more
circuits
- Variable speed compressor control
Advantages
• Energy optimisation of the whole refrigeration appliance
• One controller for several different refrigeration appliances
• Integrated display at the front of the controller
• Built-in data communication
• Built-in clock function with power reserve
Menu survey ...................................................................................................... 22
Connections ...................................................................................................... 26
Data ...................................................................................................................... 28
Ordering ............................................................................................................. 29
Principle
The temperature in the appliance is registered by one or two
temperature sensors which are located in the air flow before the
evaporator (S3) or after the evaporator (S4) respectively. A setting
for thermostat, alarm thermostat and display reading determines
the influence 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 compressors, the controller has 5
relay outputs for dedicated applications.
Functions
• Day/night thermostat
• Product sensor S6 with separate alarm limits
• Switch between thermostat settings via digital input
• Start of defrost via schedule, digital input or network
• Natural or electric defrost
• Stop of defrost on time and/or temperature
• Coordination of defrost across several controls
• Pulsing of fans when thermostat is satisfied
• Case cleaning function for documentation of HACCP procedure
• Rail heat control via day/night load or dew point
• Door function
• Control of two compressors or one variable speed compressor
• Control of night blinds and light
• Factory calibration that will guarantee a better measuring
accuracy than stated in the standard EN ISO 23953-2 without
subsequent calibration (Pt 1000 ohm sensor)
• Integrated MODBUS communication with the option of
mounting a LonWorks or DANBUSS
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User Guide | Controller for SemiPlugin appliance, AK-CC 460
Applications
The controller supports the following 3 control modes:
- Sequential On/Off control of 2 compressors.
Output 1 will form the base load, and output 2 will connect a
lower capacity so that the variation of the cabinet temperature
is kept to a minimum.
The compressors are coupled sequentially. Compressor 1 is first
in and last out.
- Cyclic On/Off control of 2 compressors.
Here the compressors must be of equal size, and they are
coupled cyclic.
The runtimes are equalized.
- Variable speed control of one compressor
Here one compressor output is used together with the analogue
0 – 10 V signal.
Enables a very precise control of the cabinet temperature.
Control with two compressors
When the controller calls for refrigeration, compressor 1 will be
cutin to the circuit first.
After the delay time, compressor 2 will be coupled to the circuit.
When the temperature has reached the middle of the differential,
compressor 2 will be cut out.
Compressor 1 will continue until the temperature has reached the
cut-out value. Then it will cut out. When the temperature again
reaches the middle of the differential, compressor 1 will be cutin to
the circuit again.
If compressor 1 cannot maintain the temperature within the differential, compressor 2 will also be cutin to the circuit.
The compressor's settings for ”Min On time” and ”Min Off 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.
With cyclic control the compressor with the lowest runtime will be
started first.
If one of the compressors has been running continuously for
two hours, the compressors will be alternated to assure runtime
equalization.
Variable speed control
Here the compressor will be started when the controller requests
cooling.
The analogue output will then be used to control the speed so
that the temperature is kept very accurate at the reference.
The actual reference is the set cut-out temperature plus half the
set difference.
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User Guide | Controller for SemiPlugin appliance, AK-CC 460
Temperature control
The temperature in the appliance is registered by one or two
temperature sensors which are located in the air flow 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 influence each
individual function, e.g. 50% will produce an equal value from
both sensors.
There are separate settings for day operation and night operation.
Temperature monitoring
Just as it 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 influence 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.
Thermostat bands
Thermostat bands can be used beneficially for appliances where
different product types are stored which require different temperature conditions. It is possible to change between the two
different 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 differences
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 effect 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 optional 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.
S7 brine sensor
The temperature at the brine inlet is monitored by the S7
temperature sensor. If the temperature gets higher than the set
value, the controller will reduce the cooling capacity, so that the
load on the heat exchanger is reduced.
For two-compressor operation, compressor 2 will be taken out of
operation.
With variable speed control the compressor speed will be reduced
to the value defined by parameter "c93".
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User Guide | Controller for SemiPlugin appliance, AK-CC 460
Appliance cleaning
This function makes it easy for the shop’s staff 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 first 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).
Documentation
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.
- + + °C
1 ÷ + Fan
2 ÷ ÷ Off
3 + + °C
Defrost
Depending on the application you may choose between the following defrost methods:
Natural: Here the fans are kept operating during the defrost
Electric: The heating element is activated
Defrost sequence
1) Defrost
2) Waiting position after defrost
3) Drip off
4) Delay of fan
Start of defrost
A defrost can be started in different ways
Interval: Defrost is started at fixed 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 fixed refrigeration time
intervals, in other words, a low need for refrigeration will
”postpone” the defrost
Schedule: Here defrost can be started at fixed 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 any of
them is activated a defrost will be started.
Stop of defrost
Defrosting can be stopped by either:
• Time
• Temperature (with time as safety).
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User Guide | Controller for SemiPlugin appliance, AK-CC 460
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 on demand
Based on refrigeration time
When the aggregate refrigeration time has passed a fixed time, a
defrost will be started.
Max. 10
System manager
Melting function
This function will stop the air flow 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 for the set melting period. The frost will be melted so that
the air flow 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 four hours.
If the controller is equipped with data communication, the clock
will automatically be updated from the system unit.
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AO
0 – 10
c46
c47
c48
80G437
User Guide | Controller for SemiPlugin appliance, AK-CC 460
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 effect must be max. i.e.100%. (o87)
• 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 the rail heat will be controlled by the setting in
"d27" (Off, On or pulsing).
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 cutout period (cold room)
- during night operation and during the thermostat’s cutout pe-
riod (appliance with night lid /blind)
Rail heat
Dew point
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 refrigeration appliance may rise as a result of the power
supply from fans. In order to prevent this situation the controller
can stop the fans if the temperature at S5 exceeds a set limit value.
Variable speed compressor control
The variable speed compressor control is using these 3 settings:
- Start speed - c47. After starting the compressor, this speed will
be maintained for 10 seconds. Hereafter the speed can vary
between min. and max speed
- Max. speed – c48. The max allowed speed for the compressor
- Min. speed – c46. At low requested capacity, the set minimum
speed will be maintained until the compressor is cut out.
Note: the voltage on the analogue output is scaled for the
maximum frequency range from min. speed to 100 Hz, meaning
that if the max. speed is set lower than 100 Hz, the max. output
voltage will be below 10 V.
10 V
V Max.
V Start
V Min.
V
Active voltage range
Fmin
Fstart
Fmax
Danfoss
100 Hz
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User Guide | Controller for SemiPlugin appliance, AK-CC 460
Light function
The function can be used for controlling the light in a refrigeration
appliance or in a coldroom. It can also be used for controlling a
motorised night blind.
The light function can be defined in three ways:
- the light is controlled via a signal from a door contact. Together
with this function a time delay can be set so that the light is kept
on for 2 minutes after the door has been closed.
- 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.
The light load must be connected to the NC switch on the relay.
This ensures that the light remains on in the appliance if power to
the controller should fail.
The light is switched off when "r12" (Main switch) is set to off (see
o98).
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 off, the night blinds close again.
When the night blinds are closed, it is possible to open them and
switch on the light using a switch signal on the digital input. If this
input is activated, the night blinds will open and the refrigeration
appliance can be filled with new products. If the input is activated
again, the blinds close again.
A night blind is open and light is switch on when the appliance
cleaning function is activated.
A setting can define that the night blind is open when "r12" (Main
switch) is set to off (see o98).
When the night blind rolls down, the fans can be stopped so that
the air circulation does not interrupt the positioning of the blind.
The desired stop time must be set in P65.
The motor for the night blinds must be connected to the same
relay as the light function.
Digital inputs
There are two digital inputs DI1 and DI2 with contact function and
one digital input DI3 with high voltage signal.
DI1 and DI2 input can be used for the following functions:
- Retransmission of contacts position via data communication
- Door contact function with alarm
- Starting a defrost
- Main switch - start/stop of cooling
- Night setback
- Thermostat bands switch
- General alarm monitoring
- Case cleaning
- Override of night blinds
- Case shut down
- Coordinated defrost (DI2 only)
DI3 is predefined as input from the safety circuit for the
compressors. When the voltage on the input is interrupted, the
compressors will stop, and the alarm "A97 - Comp.Safety" will be
activated.
Door contact
The door contact function can via the digital inputs be defined for
two different 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 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.
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User Guide | Controller for SemiPlugin appliance, AK-CC 460
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 or DANBUSS 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
Gateway software must be Version 6.20 or higher.)
Display
The controller has one plug for a display. Here display type EKA
163B or EKA 164B (max. length 15 m) can be connected.
EKA 163B is a display for readings.
EKA 164B is both for readings and operation.
The connection between display and controller is with a cable
which has a plug at both ends.
If the distance between display and controller is greater than 15 m,
the connection must take another form.
! Address o03 > 0
An extra module must also be mounted in the controller if data
communication is used.
The built-in MODBUS data communication is used so that the
display connection and the data communication to the other
controllers must take place via a module. The module can be:
Lon RS 485, DANBUSS or MODBUS.
When a display is to be connected to the built-in MODBUS, the
display can advantageously be changed to a type with screw
terminals. I.e. the type EKA 163A or EKA 164A.
If connection of two displays is required, one must be connected
to the plug (max. 15 m) and the other must then be connected to
the fixed data communication.
The controllers address must be set higher than 0 in order for the
display to be able to communicate with the controller.
Important
All connections to the data communication MODBUS, DANBUSS
and RS 485 must comply with the requirements for data
communication cables. See literature: RC8AC.
AK-CC 450/550
AK-CC 460
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-CC 460
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
Railheat link to dew point / Enhanced railheat --- Dew point
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