Tripp-Lite SRCOOL60KCW El Manual Del Propietario página 25

4. Initial Startup
5
Execute the Modbus Recorder* program via the RS485 interface and calculate Td and
=1.5 x (T2-T1) [the time difference between 28.3% (T1) and 63.2% (T2) x 1.5]
T
Td (Pseudo Dead Time) may be defined as Td= T1 –
* Various OS versions of this tool can be found at http://www.modbustools.com/modbus_poll.html
6
Calculate the best PID values in different modes in accordance with the below table:
Mode
P
PI
PID
* G (response gain): it varies with opening values and therefore, the medium opening or the opening at a medium flow rate is selected as the
reference point.
** Reset and Derivative are defined: Reset=I/P , Derivative=D/P
7
The I and D values can be found from the Reset and Derivative values.
8
Enter the PID values found on the control panel, start the automatic mode and observe any temperature oscillations. If the
temperature is stable, record the value on a sheet of paper and input the adjusted set values (including supply air and return air
temperature and humidity, fan speed, inlet water temperature, and outlet water temperature) via the SNMP interface.
y y
Operation trial
1. Confirm that the cooling unit is in automatic mode and observe if the supply and return air temperature and humidity, water flow
rate and water temperature are stable.
2. Change the set point, record the stability time (reaching the set point of supply air temperature) via the SNMP interface, and
observe if there is instability and temperature oscillation.
3. Export and store the data.
T
Gain
tau/ (Td x G*)
0.9 tau/ (Td x G*)
1.2 tau/ (Td x G*)
25
values. The definition is as follows:
T
Reset**
0.3/ Td
0.5/ Td
Derivative**
0.5 Td