Danfoss EKE 1A User Manual page 43

Superheat controller, Type EKE 1A, 1B, 1C, 1D
Parameter Function
N119 SH close setpoint
I082 S2 sensor configuration
I086 Pe transmitter configuration
Minimum Stable Superheat (MSS)
The controller will be searching for the minimum stable superheat between an upper and lower boundary specified
by the user. Then if the superheat is stable at a certain value, the controller decreases the superheat reference, if the
SH gets unstable, the SH reference is raised again.
The goal of this method is to search for the lowest possible superheat that can be obtained while still maintaining a
stable system.
Figure 59: Minimum Stable Superheat (MSS)
EKE 1A
Applicable
Table 25: MSS parameters
Parameter Function
R102 Operation mode
N021 SH reference mode
N009 SH max. value
N010 SH min. value
N018 MSS Stability
T0 variant factor (Value from 0 to
N129
1)
N117 SH close Function
N119 SH close setpoint
I082 S2 sensor configuration
I086 Pe transmitter configuration
Load AP
In Load ap application, SH reference follows a defined curve as shown in the diagram. This two-point curve is
defined by SH max and SH min. These two values must be selected in such a way that the curve is situated between
the MSS curve and the curve for average temperature difference ΔTm (temperature difference between media
temperature and evaporating temperature). This makes the regulation more stable compare to MSS because it does
not seek a usability.
 WARNING:
Besides the Temperature Sensor S2 and pressure sensor Pe, in this mode a third temperature sensor is needed S3.
© Danfoss | Climate Solutions | 2022.06
Description
It is recommended to set the SH close setpoint 2k below the minimum SH.
Default value =2 K (recommended).
-Selection of the used evaporator temperature sensor S2
-Selection of the used evaporator pressure sensor Po
1B 1C 1D
Description
0 = SH Control
2 = MSS
Maximum allowed SH reference in the range.
Minimum allowed SH reference in the range.
The amount of allowed fluctuation in the superheat before the reference is changed (the range at which the SH
is considered stable)
Defines how Pressure variation (From Pe) influence the SH reference.
Safety feature to prevent the flooding of the liquid into the compressor. When the measured superheat goes
bellow the SH close setpoint (parameter N119) 0 = Off | 1 = On, default = 1
It is recommended to set the SH close setpoint 2k below the minimum SH.
Default value =2 K (recommended).
-Selection of the used evaporator temperature sensor S2
-Selection of the used evaporator pressure sensor Po
Figure 60: Minimum stable Superheat
Q
o
100 %
40 %
10 %
Min. SH Max. SH
BC398828796060en-000101 | 43
Danfoss MSS
Superheat