21
or program or the type of load you are heating. To use
the Tuning feature:
1.
Select the temperature at which you intend to
operate. If you will be running a program,
enter the value of Set point 1 as a single set
point.
2.
Load your furnace with a characteristic sample of
the load you will be heating.
3.
Push “SEL” button until “AT” is displayed, then
push “UP” or “DOWN” button to turn “AT” “on.”
During the operation, “TunE” flashes in the lower display.
Do not make any adjustments to the controller param-
eters during this period. The self tuning is finished when
“TunE” no longer flashes in the lower display.
Self tuning will calculate values for:
Proportional band - P
Integral - I
Derivative - d
•
Self tuning cannot be initiated while running a
program.
•
A power failure will cause the AT parameter to
revert back to “OFF”. (Reset tune parameter to
“ON” using the “UP” button).
•
In the case of alarm conditions during tuning,
those conditions will flash alternately with
“TunE.”
The next time you use your furnace, push “SEL” button
until “AT” is displayed, then push “UP” or “DOWN” button
to turn tune “oFF.”
Furnace Loading:
1.
For best results use only the center 2/3
of the furnace chamber.
NOTE
For processes which cannot tolerate the overshoot
naturally generated during the tuning process, se-
lect “Lo” rather than “on” for the “AT” setting. The
“Lo” setting will tune your furnace at a temperature
below your set point, then apply the result to your
set point. This approach prevents the necessary
tuning overshoot from exceeding your actual set
point.
O
PERATION
OF
4 R
AMP
& 4 D
WELL
P
ROGRAMMABLE
M
ODELS
