ACH550-01 User's Manual
102
Application macros and wiring
4. Cooling tower fan
This application macro is for cooling tower fan applications
where the fan speed is controlled according to the signals
received from the transducer. See the figure below.
When using a direct speed reference in the AUTO mode, the
speed reference must be connected to analogue input 1 (AI1)
and the START command is given with digital input 1 (DI1). In
the HAND/OFF mode, the speed reference and START
command are given through the control panel (operator keypad).
If process PI(D) is used, the feedback signal must be connected
to analogue input 2 (AI2). By default, the setpoint is set from the
control panel, but it can also be changed to analogue input 1.
Process PI(D) must be commissioned and adjusted with
parameters (
Group 40: PROCESS PID SET 1
) or using the PID
control assistant (recommended).
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C
opyright
2007
ABB
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