Survey Of Functions - Danfoss EKC 326A User Manual

Survey of functions

Function
Normal display
The normal display shows the pressure in the gas cooler. The pressure is measured
using Pgc. The measurement can also be seen in menu U06.
The control reference can be viewed by pressing both buttons.
If a pressure transmitter is mounted to display the receiver pressure, the measure-
ment can be brought up on the display by pressing the lower button. The measure-
ment can also be seen in menu U07.
Gas pressure control
Defining the reference line
Set the end point for the reference line in the transcritical range. Set the desired tem-
perature value at 100 bar.
The reference
The reference is pre-programmed to follow the optimal COP from the pressure/en-
thalpy chart. See the illustration on page 2.
The current reference can be read off in menu U03.
Start/stop of regulation
This setting can be used to start and stop regulation.
Stopping regulation will always cause the valve will close at the value set in "n87" and
"n93".
The function in o02 requires that it has been defined.
Max. opening degree
The ICMTS-valve's opening degree can be limited here.
Limitation takes place by limiting the voltage signal that is sent to the valve actuator.
The setting is expressed as a % of the total opening degree. The voltage signal of 0-10
V on the output will be limited correspondingly.
Minimum opening degree
The closing degree of the ICMTS valve can be limited here.
Limitation takes place by increasing the lower part of the voltage signal that is sent to
the valve actuator.
The setting is expressed as a percentage of the total opening degree. The output volt-
age signal of 0-10 V will be limited correspondingly.
The gas cooler's max. pressure
This is where you define the maximum pressure permitted in the gas cooler. If the
pressure reaches this value, the valve is open as set in "n32 OD max".
P-band to force open the valve from normal regulation
P-band under "n69, Pgc Max lim", where the valve is forced open so that the valve is
fully open if the pressure reaches "n69, Pgc Max lim".
The pressure is not critical, so opening of the valve will take place under controlled
conditions.
The gas cooler's min. pressure
This is where you define the minimum pressure permitted in the gas cooler.
Subcooling is required to be regulated according to temperature
Set the desired subcooling in K.
P: Amplification factor Kp
If the Kp value is reduced the regulation becomes slower.
I: Integration time Tn
If the Tn value is increased the regulation becomes slower
Increasing refrigeration capacity
This function increases the gas pressure reference. Control moves from optimum
COP control to maximum refrigeration control. (The pressure increases, temperature
remains unchanged and the total heat content increases.)
Set the pressure increase value.
The function is activated by closing the switch function on terminals 1 and 2. (see
o02)
6 Manual RS8FM602 © Danfoss 02-2016
Para- Parameter by operation via
meter data communication
U06 Pgc bar
U07 Prec bar
Gas cooler control
n99 T100
U03 Pgc Ref
r12 Main Switch
n32 Vhp OD Max
n87 Vhp OD Min
n69 Pgc Max
n70 Pgc P-band
n81 Pgc Min
n79 dT Subcool
n04 Kp Gascool
n05 Tn Gascool
n88 Pgc Cap Offset
EKC 326A