General pid constants by application, Proportional band only (p), Proportional wth integral (pi) – Watlow CLS User Manual
Page 113: Pi with derivative (pid), Proportional with integral (pi)
PID Tuning and Control
CLS User’s Guide 105
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)
PB: Set the PB to 7% of the setpoint (SP) (Example: Setpoint = 450, so
Proportional Band = 31).
Proportional with Integral (PI)
PB: Set the PB to 10% of SP (Example: Setpoint = 450, so PB = 45).
Set TI to 60.
Set TD to Off.
Set the Output Filter to 2.
PI with Derivative (PID)
PB: Set the PB to 10% of the SP (Example: Setpoint = 450, so PB = 45).
Set the TI to 60.
Set the TD to 15% of the TI (Example: TI = 60, so TD = 9).
Set the Output Filter to 2.
The next table shows general PID constants by application.
Application
PB
TI
TD
Filter
Output
Type
Cycle
Time
Action
Electrical heat w/ SSR
50
º
60
15
4
TP
3
Reverse
Electrical heat w/ EM
relays
50
º
60
15
6
TP
20
Reverse
Cool w/ solenoid valve
70
º
500
90
4
TP
10
Direct
Cool w/ fans
10
º
off
10
4
TP
10
Direct
Electric heat w/ open
heat coils
30
º
20
off
4
DZC
-
Reverse
Gas heat w/ motorized
valves
SP>1200
60
º
100
120
240
25
40
8
DAC or
SDAC
-
Reverse
Electric heat w/ phase
angle controlled SCR
60
º
60
15
4
DAC or
SDAC
-
Reverse
Extuders w/ cooling gas
heat w/ SSR (set spread
to 8)
50
º
300
120
4
TP
3
Reverse