Table of Contents
Advertisement
Configuration - continued
Set control of MT compressors
1. Go to Configuration menu
2. Select Suction group MT
3. Set values for the reference
Press the +-button to go on to the
next page
4. Set values for capacity control
Press the +-button to go on to the
next page
56
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 the
settings:
- P0 optimisation
- Suction pressure = -10°C
The settings are shown here in the
display.
In our example we select:
-VSD + single step
- 3 compressors
- P0 as signal to the regulation
- Cyclic
Capacity controller RS8HF102 © Danfoss 2017-07
3 - Reference mode
Displacement of suction pressure as a function of external
signals
0: Reference = set reference + night offset + offset from external
0-10 V signal
1: Reference = set reference + offset from P0 optimization
Setpoint ( -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 value at max. signal (10)
Offset at min input (-100 to +100 °C)
Displacement value at min. signal (0 V)
Offset filter (10 - 1800 Sec)
Here you can set how quickly the reference must become ef-
fective.
Night Offset 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 via a network signal
Night Offset (-25 to +25 K)
Displacement value for suction pressure in connection with an
active night setback signal (set in Kelvin)
Max reference (-50 to +80 °C)
Max. permissible suction pressure reference
Min reference (-80 to +25 °C)
Min. permissible suction pressure reference
4 - Compressor application
Select the compressor application required
Lead compressor type (For LT only)
• Variable
The following options are available for variable:
No. of compressors
Set number of compressors (Total)
(max. 2 if parallel compressor is also selected)
No. of unloaders
Set number of unloader valves
Ext. compressor stop
An external switch can be connected which will start and stop
the compressor control.
Control sensor
Po is used for control
Step control mode
Select coupling pattern for compressors
Cyclic: Runtime equalisation between compressors (FIFO)
Best fit: Best possible adaptation of capacity (minimum capac-
ity jump)
Pump down
Select whether a pump down function is required on the last
running compressor
Pump down limit To (-80 to +30 °C)
Set the actual pump down limit
Synchronous speed
No: There will be two analog outputs available.
Yes: There will be one analog output.
VSD min speed (0.5 – 60.0 Hz)
Min. speed where the compressor must cutout
VSD start speed (20.0 – 60.0 Hz)
Minimum speed for start of Variable speed drive (Must be set higher
AK-PC 772A
Advertisement
Table of Contents
