Rockwell Automation 900-TC32 Digital Temperature Controllers, Series B - Manual (Page 346)

Publication 900-UM007D-EN-E - January 2011
6-6 Troubleshooting & Error Indication
Timing Status Meaning Countermeasures Page
During operation Overshooting
Undershooting
Hunting ON/OFF control is
enabled (default:
ON/OFF control
selected). Select PID control and execute either ST
(self-tuning) or AT (Auto-Tuning).
When using self-tuning, turn ON the power
supply to the Temperature Controller and load
(heater, etc.) at the same time, or turn ON the
load power supply first. Accurate self-tuning and
optimum control will not be possible if the power
supply to the load is turned ON after turning ON
the power supply to the Temperature Controller. 3-30
Control cycle is longer
compared with the
speed of rise and fall in
temperature Shorten the control cycle. A shorter control cycle
improves control performance, but a cycle of 20
ms minimum is recommended in consideration of
the service life of the relays. 3-17
Unsuitable PID
constant Set appropriate PID constants using either of the
following methods.
Execute AT (autotuning).
Set PID constants individually using manual
settings.
3-30
HS alarm operation
fault Use breeder resistance if the problem is due to
leakage current. Also investigate the errors
detected by the HS alarm function. 3-46
Temperature is not
rising Specified operation is
unsuitable for required
control (default:
Reverse operation) Select either forward or reverse operation
depending on the required control. Reverse
operation is used for heating operations. 3-17
Heater is burnt out or
deteriorated. Check whether heater burnout or deterioration
have occurred. Also investigate the errors
detected by the Heater Burnout Alarm. 3-46
Insufficient heater
capacity Check whether the heater’s heating capacity is
sufficient. —
Cooling system in
operation. Check whether a cooling system is operating. —
Peripheral devices have
heat prevention device
operating. Set the heating prevention temperature setting to
a value higher than the configured temperature of
the Temperature Controller. —
Output will not turn ON Set to STOP (default:
RUN)
Set the RUN/STOP mode to RUN. If STOP is lit on
the display, control is stopped. 5-16
Specified operation is
unsuitable for required
control (default:
Reverse operation) Select either forward or reverse operation
depending on the required control. Reverse
operation is used for heating operations. 3-17
A high hysteresis is
configured for ON/OFF
operation (default:
1.0
°C)
Set a suitable value for the hysteresis. 3-16
Temperature Controller
will not operate Set to STOP (default:
RUN) Set the RUN/STOP mode to RUN. If STOP is lit on
the display, control is stopped. 5-16