Delta HCH1850 User Manual page 38

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5
6
7
8
Operation trial
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 the data and store them.
InfraSuite RowCool Precision Cooling –
Chilled Water
readings of time-dependent outlet air temperature and observe if the inlet and outlet
water temperatures are stable.
Use the control panel to start the manual mode and increase the opening (above
75%). Due to the internal delay of the system, the outlet air temperature will change
with the time.
Execute the Modbus Recorder program via the RS485 interface and calculate Td
Calculate the best PID values in different modes in accordance with the following
table.
Mode
P
PI
PID
The I and D values can be found from the Reset and Derivative values.
Enter the PID values found on the control panel, start the automatic mode, and
make continuous observation of temperature oscillation. If the temperature is
stable, record the value on a sheet of paper and output 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.
Gain
tau/ (Td x G)
0.9 tau/ (Td x G)
1.2 tau/ (Td x G)
34
Reset Derivative
0.3/ Td
0.5/ Td 0.5 Td