User`s guide

The grey
side of the
ECL Card
Basic set-up
26b
7 Neutral zone, Nz
Circuit Setting range Factory setting
I 0 ... 9 K 3 K
Set the neutral zone to a high value if you can
accept a high variation in ow temperature.
When the actual ow temperature is within the
neutral zone, the controller does not activate the
motorized valve.
The neutral zone is symmetrical around the desired ow
temperature value, i.e. half the value is above and half the value is
below this temperature.
Control parameters (lines 4-7) are overruled if thermo actuator is
chosen (OFF).
If you want to tune the PI regulation precisely, you can
use the following method:
• Set the integration time (line 5) to its max. value
(999 sec.).
• Decrease the value for the proportional band (line 4) until the
system starts hunting with a constant amplitude (it might be
necessary to force the system by setting an extreme value).
• Find the critical time period on the temperature recording or
use a stop watch.
Temp.
Critical time period
Time
This time period will be characteristic for the system, and you can
evaluate the settings from this critical period.
Integration time = 0.85 x critical time period
Proportional band = 2.2 x proportional band value in the
critical time period.
If the regulation seems to be too slow, you can decrease the
proportional band value by 10%.
Make sure there is a consumption when you set the parameters.