52
Capacity
controller RS8ER302 © Danfoss 2016-02
AK-CH
650
1. Go to Configuration menu
2. Select Suction group
3. Set values for the reference
Press the +-button to go on to the
next page
4. Set values for capacity control
Configuration - continued
The configuration menu in the
Service Tool has changed now.
It
shows the possible settings for the
selected plant type.
In our example we select:
- 4 compressors
- P0 as signal to the regulation
- Refrigerant = R404A
- Equalisation of working hours
- Value for speed regulation
Speed regulation can always only
be on compressor number 1.
The settings are shown here in the
display.
Not all compressors can have their
speed adjusted. If there is any doubt,
contact your compressor supplier.
In our example we select the
settings:
- Suction set point = -15°C
- Night offset value = 5 K.
The settings are shown here in the
display.
There are several pages, one after
the other.
The black bar in this field tells you
which of the pages is currently
displayed.
Move between the pages using the
+ and - buttons.
3 - Reference mode
Displacement of suction pressure as a function of external
signals
0: Reference = set ref night offset from
external 0-10 V signal
1: Reference = set ref offset from P0 optimization
+ Night displacement
Set point ( -80 to +30°C)
Setting of required suction pressure in °C
Offset via Ext. Ref
Select whether a 0-10V external reference override signal
is required
Offset at max input (-100 to +100 °C)
Displacement of reference at max. Ext. Ref. signal
Offset at min input (-100 to +100 °C)
Displacement of reference at min. Ext. Ref signal
Offset filter (10 - 1800 Sec)
Filter for displacement of reference, higher value results in
slower displacement
Night select via DI
Select whether a digital input is required for activation
of night operation. Night operation can alternatively be
controlled via internal weekly schedule or from the system
manager via data communication
Night Offset (-25 to +25 K)
Displacement of the brine temperature during night
operation (set in Kelvin)
Offset via S3
The reference selection must be displaced by a signal from
S3.
Tref S3 offset
Set the S3 temperature where it is not to be offset.
K1 S3 offset
Set the size of the change to be made in the reference
when the S3 temperature deviates 1 degree from the set-
ting. (-10 to 10 K)
Max reference (-50 to +80 °C)
Max. permissible brine reference
Min reference (-80 to +25 °C)
Min. permissible brine reference.
4 - Compressor application
Select the compressor application required
No. of compressors
Set number of compressors
No. of unloaders
Set number of unloader valves
Regulation sensor
Select either P0 or S4
P0 Refrigerant
Select refrigerant type
Po refrigerant factors K1, K2, K3
Only used if “Po refrigerant type” is set to custom (contact
Danfoss for information)
Step control mode
Select coupling pattern for compressors
Sequential: Compressors are cut in/out in strict accordance
with compressor number (FILO)
Cyclic: Runtime equalisation between compressors (FIFO)
Best fit: Compressors are cut in/out in order to make the
best possible fit to actual load
Injection heat exchanger
If the function is selected, injection can be coordinated
with compressor operation in one of two ways:
Synchronisation: Simultaneously with compressor opera-
tion.
Pump down: Like synchronisation, but it is terminated with
pump down, where the valve is shut and the last compres-
sor disengaged once "Pump down limit" is reached.
Pump down
Select whether a pump down function is required on the
last running compressor
Set control of compressors
If you want to know more about the different configuration
options, they are listed below.
The number refers to the number and picture in the column
on the left.
