Manual

Watlow Series PD ■ 23 ■ Chapter 5 Troubleshooting
Indication Probable Cause(s) Corrective Action
Alarm will not activate or
clear.
•
Controller is in Error condition.
•
Alarm is in latched setting.
•
Alarm is silenced.
• Incorrect configuration.
• Incorrect wiring.
• Wrong output type.
•
Defective controller.
•
Determine cause of error and correct.
•
Wait for process to return to normal
and acknowledge alarm.
•
Wait for process to return to normal
and alarm will work correctly.
• Configure Alarm, Alarm Set Point, Hys-
teresis, Silencing and Latching.
• Correct wiring.
• Replace controller with correct output
type.
•
Repair or replace controller.
Controller's process value
reading is decreasing as the
actual process is increasing.
• Thermocouple is reversed wired.
•
Analog voltage or current input scal-
ing is reversed.
• Check thermocouple wire for correct po-
larity.
•
Configure correct scaling on Input page.
Controller does not control
close enough to set point.
•
PID values incorrect.
• Cycle times incorrect.
• Heat or cooling capacity incorrectly
sized for application.
• Incorrect sensor placement.
• Controller is in Manual mode (open
loop).
• Control loop action configured incor-
rect.
•
Tune controller (Auto Tune or Manual
Tune).
• Set cycle time to match hardware on
Control Loop .
• Size energy sources to match load.
• Place sensor in optimal location.
• Change to Auto mode (closed loop) on
Monitor page.
• Configure Control Loop Action on Con-
trol Loop page.
Output cycles (turns on and
off) too frequently.
• Wrong control mode. PID control se-
lected instead of ON-OFF control.
• The cycle time is set too short.
• Activate ON-OFF control on Output
page.
• Increase Output Cycle Time on Out-
put page.
Cannot access Security, Mon-
itor, Configuration or Cali-
bration page.
• Password is enabled and incorrect
password is supplied.
• Provide the correct user name and pass-
word.
Process value reads incor-
rectly
• Analog input is configured incorrectly.
• Thermocouple sensor shorted.
• Process sensor scaled incorrectly.
• Calibration offset is incorrect.
• Sensor is wired incorrectly.
• Controller calibration is incorrect or
corrupt.
• Defective controller.
• Configure control for appropriate sen-
sor input on Analog Input page.
• Repair wiring or replace sensor.
• Set scaling on Analog Input page.
• Correctly set calibration offset.
• Wire sensor per wiring section.
• Recalibrate controller.
• Repair or replace controller.