Watlow Series D8 - Manual (Page 135)

Series D8 User’s Guide Chapter 5: Tuning and Control
Doc. 0600-3120-2000 Watlow Anafaze 117
General PID Constants by Application
This section gives PID values for many applications. They are
useful as control values or as starting points for PID tuning.
Proportional Band Only (P)
Set the proportional band to seven percent of the set point.
(Example: Set point = 450, proportional band = 31).
Proportional with Integral (PI)
• Set the proportional band to ten percent of set point.
(Example: Set point = 450, proportional band = 45).
• Set integral to 60.
• Set derivative off.
• Set the output filter to 2.
Proportional and Integral with Derivative (PID)
• Set the proportional band to ten percent of the set point.
(Example: Set point = 450, proportional band = 45).
• Set the integral to 60.
• Set the derivative to 15 percent of the integral.
(Example: Integral = 60, derivative = 9).
• Set the output filter to 2.
Table 5.4 shows general PID constants by application.
Table 5.4 General PID Constants
Application
Proportional
Band
Integral Derivative Filter
Output
Type
Cycle
Time
Action
Electrical heat
with solid state
relays
50 ° 60 15 4 DZC - Reverse
Electrical heat
with electrome-
chanical relays
50 ° 60 15 6 TP 20 Reverse
Cool with sole-
noid valve
70 ° 500 90 4 TP 10 Direct
Cool with fans 10 ° Off 10 4 TP 10 Direct
Electric heat
with open heat
coils
30 ° 20 Off 4 DZC - Reverse
Gas heat with
motorized
valves
Set Point>1200
60 °
100 °
120
240
25
40
8 Analog - Reverse