Alfa Laval AquaFirst
Installation, service and operating instruction
33
8.5
Trending parameters
A lot of different variables can be recorded or trended.
It can be temperatures’ measurement, valves or pumps’
signals, ipsothermic contacts, alarms, thermal treatments etc.
1. Press
key to access to Service Menu, then click on “Continue.
2.
Select “Trending” in the menu
3.
Select “Points in Trend”.
The first time you enter this menu, the list is empty.
4. To add a variable to trend; choose
.
5. Mark the variable to follow and press the wheel.
In this example the Secondary outlet temperature, S1.
6. Validate the variable by ticking in the Trend Log box. If this box is
empty the variable is in the list but it is not record.
There are two different ways to record:
a) Only the temperature change is recorded. This saves memory and
allows a longer sampling period compared to method 2.
Select the record hysteresis. In our case, every 1°C temperature
change is recorded. You can change the hysteresis value by clicking
on it.
b) Record on a time base, whatever the temperature changes or not.
Note that this method consumes memory, especially if a short time
base is selected. Here is the time base selected to 10 minutes
recording (1 record every 10 minutes).
For method
a
set “Trend cycle” to zero, for method
b
, set “Trend Hyst” to zero.