AEC Econo-Cool Chillers - Manual (Page 36)

AEC Water Temperature Control Units Page 35
4-8 Controller Internal Switches
The controller is set up and tested at the factory for optimum operation, and adjusting
the internal switches is not necessary. If the controller does not work properly, or you
suspect someone has accidentally changed some settings, there are two things to do.
First, perform the Auto-Tune procedure described in Section 4-10 on Page 36. If that
doesn’t work, restore the controller to the orig-inal factory settings as described in
Section 6-3 on Pages 52 to 59.
4-9 Controller Factory Setup
The controller is set up and tested at the factory for optimum operation, and in most
cases doesn’t need to be adjusted. If the controller does not work properly, or you
suspect someone has accidentally changed some settings, you can do two things. First,
perform the Auto-Tune Procedure described in the following section. If that doesn’t
work, restore the control to the original factory settings as described in Section 6-3 on
Pages 63.
For your protection, all menu modes and levels except 0 and 1 are locked out at the
factory. Level 2 is unlocked for units with factory-installed communications options.
4-10 Auto-Tuning the Controller
The Auto-Tune function lets you fine-tune the control PID to process requirements.
Activate the Auto-Tune function whenever the process under control changes. Don't be
alarmed by control response. It may take the process temperature above and below the
set points as many as three (3) times. It will then level off and control to the process set
point. Auto-tuning can take up to 45 minutes, and is best done before any product is
run.
To auto-tune the controller:
„ Press and hold down the
AT
AT key for two (2) seconds until the AT indicator
flashes.
The AT LED flashes to indicate that the control is tuning itself.
When the
AT LED light stops flashing, the controller is tuned and ready for operation.