Watlow Series 1500 - Manual (Page 58)

Technical Reference
Tuning
CAUTION:
Be sure the Series
1500 is in a Warm
Start condition
(DIP Switch #6
OFF) In order to
save your tunlng
entrles. Also
record your
experimental, and
then final settlngs
on a copy of the
Guarded Access
Chart available In
this sectlon of the
manual.
For optimum control performance, it is necessary to tune the Series 1500 to your
thermal system. At this point you should already have a program profile entered into
the 1500. This profile needs to be as nearly typical of your system requirements as
you are able to predict.
Recommended Tuning Reference
There are a number of quality references on the art of tuning electronic controllers to
the systems they control. If you are not an instrument technician qualified to tune
thermal systems, we suggest that you obtain and become familiar with the reference
below before attempting to tune your system. Remember that the time you spend
tuning your system is relative to the quality of control you need.
Process Control Instrumentation Technology - Third Edition
by
Curtis D. Johnson Hardcover, 1982, 497
pp.
ISBN: 0-471-05789-4
approx. $37.00
“Its overall objective is to provide instructional material for a general understanding of
process control characteristics such as elements, modes, and stability along with
detailed knowledge of measurement technique, control mode implementation, and
final control element functions.” Johnson
Using a Chart Recorder
The tuning procedure will be greatly simplified if you use a chart recorder to assist in
tuning the Series 1500. See Page 35 for analog retransmit outputs to connect to a
chart recorder. Refer to Page 52 for signal conditioner output scaling.
The analog retransmit output provides a chart recorder output for both temperature
and humidity.
If you don’t have a chart recorder available, you can still plat the time vs. temperature
system response. Record the 1500’s ACTUAL display readings on graph paper with
an x, y axis to accomplish the same thing.
How to Make the 1500 a Simple ON/OFF Control
If you want your 1500 to function as a simple ON/OFF control in either channel, just
set the Proportional Band (Pb) for that channel to zero.
58 WATLOW Series 1500User’s Manual Run and Halt, Chapter 4