Danfoss EKE 1A User Manual

Figure 59: Minimum Stable Superheat (MSS)
EKE
1A
1B
1C
1D
Applicable
Figure 60: Minimum stable Superheat
Danf
os
s
84B1487.10
100 %
10 %
40 %
Superheat
Qo
Unstable region
(wet
)
Stable
region (d
ry
)
Min. SH Max. SH
Danfoss MSS
Parameter
Function
Description
N119
SH close setpoint
It is recommended to set the SH close setpoint 2k below the minimum SH.
Default value =2 K (recommended).
I082
S2 sensor conguration
-Selection of the used evaporator temperature sensor S2
I086
Pe transmitter conguration
-Selection of the used evaporator pressure sensor Po
Minimum Stable Superheat (MSS)
The controller will be searching for the minimum stable superheat between an upper and lower boundary specied
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.
Table 25: MSS parameters
Parameter
Function
Description
R102
Operation mode
0 = SH Control
N021
SH reference mode
2 = MSS
N009
SH max. value
Maximum allowed SH reference in the range.
N010
SH min. value
Minimum allowed SH reference in the range.
N018
MSS Stability
The amount of allowed uctuation in the superheat before the reference is changed (the range at which the SH
is considered stable)
N129
T0 variant factor (Value from 0 to
1)
Denes how Pressure variation (From Pe) inuence the SH reference.
N117
SH close Function
Safety feature to prevent the ooding of the liquid into the compressor. When the measured superheat goes
bellow the SH close setpoint (parameter N119) 0 = O | 1 = On, default = 1
N119
SH close setpoint
It is recommended to set the SH close setpoint 2k below the minimum SH.
Default value =2 K (recommended).
I082
S2 sensor conguration
-Selection of the used evaporator temperature sensor S2
I086
Pe transmitter conguration
-Selection of the used evaporator pressure sensor Po
Load AP
In Load ap application, SH reference follows a dened curve as shown in the diagram. This two-point curve is
dened 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 dierence ΔTm (temperature dierence 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 BC398828796060en-000101 | 43
Superheat controller, Type EKE 1A, 1B, 1C, 1D

Danfoss EKE 1A Specifications

General

Brand	Danfoss
Model	EKE 1A
Category	Controller
Language	English