TC 816 Operation Manual
THERMON…The Heat Tracing Specialists
®
Operation Manual 0503 E TC 816
Page 37 of 42
4.3.4
Parameter P19:
P HEAT
This Parameter is:
•
Valid for Temperature Controller Zones
- Zones 1 through 16
- unit in: %
•
Not valid for
Limiter Zones
•
Not valid for
Current Zones
Control mode set to PID control, see chapter 4.3.3.
With parameter P19 the proportional band (
P HEAT
) of the controlled heat tracing circuit is set in % (per-
centage). The resulting proportional band derives from the TC 816 globally set maximum temperature value
(default 700 °C).
If, for example,
P HEAT
is set to 10 % and the maximum temperature value is 700 °C, the effective pro-
portional band (p-band) is 70°C. For a
pure proportional controller
(not PID) this means that the controller
output is slowly reduced before reaching the temperature set point. In case the measured temperature equals
the set point the controller output has been reduced to 0 %. This results in the following curve:
Figure 5.1
Illustration of proportional control mode
Adjustment thresholds: 0...100
Default value:
5
Note:
With
P HEAT
set to
“0” the temperature control acts as ON/OFF control without hysteresis.
4.3.5
Parameter P20:
I HEAT
This Parameter is:
•
Valid for Temperature Controller Zones
- Zones 1 through 16
- unit in: s (seconds)
•
Not
valid for
Limiter Zones
•
Not
valid for
Current Zones
Control mode set to PID control, see chapter 4.3.3.
With parameter P20 the integration time of the control system is set in s (seconds). In the event of deviations
this control portion modifies the controller output by a speed set here (up or down).
Adjustment thresholds: 0...999
Default value:
80
Note:
With
I HEAT
set to
“0” the integral portion of the PID control is switched off.
Contr Outp (Y)
100%
0%
Temperature (X)
p-Band
Set
Point
(W)
