Danfoss EIM 365 User Manual page 19

Superheat controller, type EIM 365 (PV01)
Table 19: User defined valve
Symbolic name
n03 Valve type
n37 Max steps
n38 Max steps/sec
n39 Start backlash
n40 Backlash
n42 Comp. dir.
n56 Motor current
Decay Mode
External sensor values via Modbus
In some applications, the suction pressure and/or the refrigerant temperature on the evaporator outlet, is measured
by a system controller. This is often the case if the suction pressure is used to trigger low temperature/pressure
alarms by the systems main controller. In these cases the sensors can be omitted from the EIM 365, and the sensor
values can be received via modbus instead.
This requires that the systems main controller continuously transmits these values to the EIM 365.
If no new sensor value is received within 5 seconds of the last transmission, the sensor will revert to using the
physical sensors.
The suction gas temperature S2 and the evaporator pressure Pe can be set by writing to the registers "ext S2 Temp"
and "ext EvapPress P0" respectively.
 NOTE:
The external evaporator pressure is received in millibar so 8.4 bar absolute must be sent as 8400.
It is possible to set the S4 temperature as an external sensor value also, but since this sensor is not used in the
superheat regulation, little practical use.
Table 20: External sensor values via Modbus
Symbolic name
extEvapPress P0
ext S2temp
extS4 air temp.
Selecting a refrigerant
The controller needs to know which refrigerant is used in order to accurately control the superheat. This can be
selected by setting the "o30 Refrigerant" to the desired refrigerant as defined in the list below.
If no refrigerant is selected ("o30 Refrigerant" is set to 0 meaning the refrigerant is undefined), the "No Rfg. Sel. "
alarm is set and the controller will not start regulating.
Before refrigeration can be started , the refrigerant has to be defined. You can select the following refrigerant.
Table 21: Refrigerant settings
Symbolic name PNU
o30Refrigerant 2551
© Danfoss | Climate Solutions | 2022.09
PNU Description
3002 User defined
3032 Maximum number of steps (384 x 10 micro steps = 480 half steps)
3033 Steps per second
3034 Backlash (steps) to close in percent at startup (power on).
3035 Backlash (steps) for spindle play compensation. This is active during normal control
3037 Compensation direction
3051 Motor current
64321 0: Fast decay; 1: Slow decay; 2: Mixed decay
PNU Description
External evaporator pressure. This value can be used instead of a sensor.
2643 This registermust be written at least every 5 second, otherwise the sensor value will
be used. The entered value is in millibar
ExternalS2. This value can be used instead of a sensor.
2644 This register must be written at least every 5 second, otherwise the sensor value
will be used.
ExternalS4. This value can be used instead of a sensor. This register must be written
2646
at least every 5 second, otherwise the sensor value will be used.
Description
1= R12 10= R503
2= R22 11= R114
3= R134a 12= R142b
4= R502 13= User defined
5= R717 14= R32
6= R13 15= R227
7= R13b1 16= R401A
19= R404A 28= R744
20= R407C 29= R1270
21= R407A 30= R417A
22= R407B 31= R422A
23= R410A 32= R413A
24= R170 33= R422D
25= R290 34= R427A
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37= R407F
38= R1234ze
39= R1234yf
40= R448A
41= R449A
42= R452A