Conair MPW, MPA manual Performing An Auto Tune, b a d, Insufficient setpoint/process deviation

PERFORMING AN AUTO TUNE

5

Press Run and (the Setpoint Select button) simultaneously to begin the Auto Tune.

The Actual display will flash “At” and the current process temperature to indicate that an Auto Tune is underway.

If Auto Tune is successful, the controller automatically starts controlling using the new PID parameters.

If you press the STOP button or a fault occurs during the Auto Tune, the control enters stop mode and Auto Tuning immediately terminates. The actual display stops flashing “At.” If a fault occurred, the control will display the appro- priate error message.

ERROR MESSAGE			ERROR DESCRIPTION
			Insufficient setpoint/process deviation.
	A t	d E v
			If the absolute value of (setpoint - process
			value) is less than 25° F. The Auto Tune can-
			not be started until the temperature
			difference is at least 25° F.
			Auto Tune timed out. Auto Tune will time out
	A t	t I
			if a stable process value cannot be obtained
			5 minutes into the tune, or if the tuning
			process takes longer than 30 minutes. If this
			error occurs, verify that you followed every
			requirement under “To ensure a successful
			Auto Tune” and perform a second tune.
			Invalid PID constants were generated.
	A t	b a d
			The most likely causes of this error is a tune

started inappropriately or an external ele- ment (i.e., loose thermocouple) that upset the process while tuning was in progress. Verify that you followed every requirement under “To ensure a successful Auto Tune” and perform a second tune.

UGH004/0999 microKool Portable Chillers OPERATION 4-9