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Heat pump controller RS8GF202 © Danfoss 2015-08
AK-HP 780
Design of a compressor and pump control
Procedure:
1. Make a sketch of the system in question
2. Check that the controller’s functions cover the required
application
3. Consider the connections to be made
4. Use the planning table. / Note down the number of connections
./ add up
5. Are there enough connections on the controller module? – If
not, can they be obtained by changing an ON/OFF input signal
from voltage signal to contact signal, or will an extension
module be required?
6. Decide which extension modules are to be used
7. Check that the limitations are observed
8. Calculate the total length of modules
9. The modules are linked together
10. The connection sites are established
11. Draw a connection diagram or a key diagram
12. Size of supply voltage/transformer
1
Sketch
2
Functions
AK-HP 780
Application
Regulation of a compressor group
x
Regulation of receiver temperature
x
Regulation of compressor capacity
Regulation sensor = Sctrl
x
PI-regulation
x
Max. number of compressor steps
8
Max. number of unloaders each compressor
3
Identical compressor capacities
x
Different compressor capacities
x
Sequential operation (first in / last out)
x
Speed regulation of 1 compressor or 2 parallel compressors
x
Run time equalisation
x
Min. restart time
x
Min. On-time
x
Make a sketch of the system in question.
Follow these 12
steps
Oil management
Oil injection in compressor. Shared or individual
x
Receiver pressure control
x
Monitoring of oil level in receiver
x
Management of oil level in oil separator
x
Reset of oil management
x
Cutout of compressors at oil failure
x
Safety relays during forced compressor control
x
Temperature reference for Sctrl
Override via “night setback”
x
Override via "0 -10 V signal"
x
Regulation of receiver temperature
Regulation sensor. = S7
x
On/off control of pump
x
Speed regulation of pump
x
Safety functions
Min. suction pressure
x
Max. suction pressure
x
Max. discharge pressure
x
Max. discharge gas temperature
x
Min. / Max. superheat
x
Safety monitoring of compressors
x
Common high pressure monitoring of compressors
x
General alarm functions with time delay
10
Miscellaneous
Extra sensors
7
Option for connection of separate display
4
Separate thermostat functions
5
Separate pressostat functions
5
Separate voltage measurements
5
Max. input and output
100