Danfoss EKC 315A - Control Parameter Configuration; PID Regulation Parameters; Superheat Reference Settings; Valve and Temperature Settings

User Guide | Superheat controller, EKC 315A
© Danfoss | DCS (ADAP-KOOL®) | 2015-03
DKRCI.PS.RP0.D2.02 | 520H7653| 5
Control parameters
P: Amplication factor Kp
If the Kp value is reduced the regulation becomes slower.
n04 Kp factor
I: Integration time Tn
If the Tn value is increased the regulation becomes slower
n05 Tn sec.
D: Dierentiation time Td
The D-setting can be cancelled by setting the value to min. (0).)
n06 Td sec.
Max. value for the superheat reference n09 Max SH
Min. value for the superheat reference
Warning! Due to the risk of liquid ow the setting should not be lower than approx.
2-4 K.
n10 Min SH
MOP
If no MOP function is required, select pos. O.
n11 MOP (Bar)
(A value of 60 bar corresponds to O )
AKV valve's time period in seconds
Should only be set to a lower value if it is a decentralised plant and the suction pres-
sure uctuates a lot and in line with the opening of the AKV valve.
n13 AKV per. time
Stability factor for regulation of superheat
With a higher value the control function will allow a greater uctuation of the super-
heat before the reference is changed. The value should only be changed by specially
trained sta.
n18 Stability
Damping of amplication near reference value
This setting damps the normal amplication Kp, but only just around the reference
value. A setting of 0.5 will reduce the KP value by half.
The value should only be changed by specially trained sta.
n19 Kp Min
Amplication factor for the superheat (only in 1:1 plant)
This setting determines the ICM or AKV valve’s opening degree as a function of the
change in evaporating pressure. An increase of the evaporating pressure will result in
a reduced opening degree. When there is a drop-out on the low-pressure thermostat
during start-up the value must be raised a bit. If there is pendling during start-up the
value must be reduced a little.
The value should only be changed by specially trained sta.
n20 Kp T0
Denition of superheat regulation (Ref. appendix 6)
1: Lowest permissible superheat (MSS). Adaptive regulation.
2: Load-dened superheat. The reference is established based on the line formed by
the three points: n09, n10 and n22.
n21 SH mode
Value of min. superheat reference for loads under 10%
(The value must be smaller than ”n10”).
n22 SH Close
Standby temperature when valve closed (TQ only)
The TQ actuator is kept warm when the valve reaches its closing point. As the closing
point cannot be dened completely accurately due to tolerances and pressure varia-
tions, the setting can be changed, as required (how ”tightly”/securely the valve is to
close). See also appendices 1 and 5.
n26 TQ Kmin
Standby temperature when valve open (TQ only)
The TQ actuator’s temperature is kept low when the valve reaches its fully open posi-
tion. Here you set how many degrees the temperature is to be above the expected
open temperature in completely open position. The greater the value, the surer it
is that the valve will be open, but it will also react more slowly when it has to close
again.
n27 TQ Kmax
Max. opening degree
The ICM or AKV valve’s opening degree can be limited. The value is set in %.
The value should only be changed by specially trained sta.
n32 OD Max
Min. opening degree
The ICM or AKV valve's opening degree can be set to a specied min. value, disabling
full closure.
The value should only be changed by specially trained sta.
n33 OD Min