Start Of Controller; If The Superheating Fluctuates; If The Superheat Has Excessive Underswing During Start-Up - Danfoss EKC 315A User Manual

Start of controller

When the electric wires have been connected to the controller,
the following points have to be attended to before the regulation
starts:
1. Switch off the external ON/OFF switch that starts and stops the
regulation.
2. Follow the menu survey on page 8, and set the various para-
meters to the required values.
3. Switch on the external switch, and regulation will start.
If the superheating fluctuates
When the refrigerating system has been made to work steadily,
the controller's factory-set control parameters should in most
cases provide a stable and relatively fast regulating system.
If the system however fluctuates this may be due to the fact that
too low superheat parameters have been selected:
If adaptive superheat has been selected:
Adjust: n09, n10 and n18.
If load-defined superheat has been selected:
Adjust: n09, n10 and n22.
If the superheat has excessive underswing
during start-up
If you regulate with valve type AKV:
Adjust n22 a little bit up and/or n04 a little bit down.
If you regulate with valve type TQ:
Adjust n26 a littlle bit down
EKC 315A Manual RS8CS302 © Danfoss 07-2005
4. Follow the actual room temperature or superheat on the
display.
(On terminals 2 and 5 a current signal can be transmitted
which represents the display view. Connect a data collection
unit, if applicable, so that the temperature performance can be
followed).
Alternatively it may be due to the fact that the set regulation
parameters are not optimal.
If the time of oscillation is longer than the integration time:
(T > T , (T is, say, 240 seconds))
p n n
1. Increase T to 1.2 times T
n p
2. Wait until the system is in balance again
3. If there is still oscillation, reduce K
4. Wait until the system is in balance
5. If it continues to oscillate, repeat 3 and 4
If the time of oscillation is shorter than the integration time:
(T < T , (T is, say, 240 seconds))
p n n
1. Reduce K by, say, 20% of the scale reading
p
2. Wait until the system is in balance
3. If it continues to oscillate, repeat 1 and 2.
by, say, 20%
p
13