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RS8GM222 © Danfoss 10-2014
AK-CC 750 - 080Z0130 & 080Z0139
Principle
Up to four valves can be connected. One for each solid state
output.
Control can be carried out with electrically operated expansion
valves type AKV.
Or injection can take place with thermostatic expansion valves
(TEV) where the temperature will then be regulated with solenoid
valves type EVR or similar.
Adaptive superheat with AKV valve
The evaporating temperature is measured with pressure transmit-
ter P and the superheat with the pressure transmitter and the S2
sensor.
The function contains an adaptive algorithm that independ-
ently adjusts the valve’s opening degree, so that the evaporator
constantly delivers optimum refrigeration at lowest possible
superheat.
The superheat reference will be limited by the settings for min.
and max. superheat.
If the superheat is very low, the valve may be closed very quickly
using the "SH closed" setting.
When the superheat has dropped to 2°F over the "SH closed" limit,
this function will reduce the degree of opening of the valve so
that the valve will with certainty remain closed if the superheat
fall to the "SH closed" value. To ensure that the close function does
not generate the general superheat regulation, the "SH closed"
setting must be at least 2°F lower than "SH min".
One pressure transmitter can supply signals to several controllers
if they regulate refrigeration points on the same suction line. But if
a valve is mounted in an evaporator’s suction line, say, a KVP / KVQ
or PM, the pressure transmitter must be placed before the valve.
The signal can now only be used by the relevant controller.
Refrigerant
Before regulation can be commenced, the refrigerant must be
defined.
You can directly select one of the current refrigerants:
1 R12
11 R114
21 R407A
31 R422A
2 R22
12 R142b
22 R407B
32 R413A
3 R134a
13 Brugerdefineret
23 R410A
33 R422D
4 R502
14 R32
24 R170
34 R427A
5 R717
15 R227
25 R290
35 R438A
6 R13
16 R401A
26 R600
36 XP10
7 R13b1
17 R507
27 R600a
37 R407F
8 R23
18 R402A
28 R744
38 R1234ze*
9 R500
19 R404A
29 R1270
39 R1234yf*
10 R503
20 R407C
30 R417A
*) Only 080Z0139
If a new refrigerant is demanded which is not as yet contained
on the list you may select ”User-defined” which is subsequently
set with data for the refrigerant in question. The values can be
ordered from Danfoss.
Warning: Incorrect selection of refrigerant can cause damage to
the compressor.
MOP control
(MOP = Max. Operating Pressure)
The MOP function limits the valve’s degree of opening as long as
the evaporating temperature measured by S1 is higher than the
set MOP temperature. The function can only be active when the
AKV injection valve function is ON.
Start/stop of injection
The injection can be stopped separately for each evaporator sec-
tion.
Liquid injection
