Extech Instruments 96VFL

33 VFL Series User Manual v2.3 12/20
15. Appendix A: Troubleshooting
Errors
Probable Cause
Action
Sensor break or sensor not
connected.
Connect or replace sensor.
A/D converter failure.
Service required. Check for
EMI or RFI interference.
Auto Tune time-out error.
Manually tune control.
Keypad not
functioning
Keypad locked.
Keypad defective.
Check the ‘LOCK’ parameter.
Service unit.
Process value unstable
Improper PID tuning.
Tune the controller.
No heat or output
Fuse blown.
Incorrect wiring.
Heater defective.
Check wiring and fuse.
Check heater.
LEDs and display not
lighting up
No power to controller.
Controller failure.
Check power connection.
Service meter.
Process Value changed
abnormally
Electromagnetic (EMI) or Radio
Frequency (RFI) interference.
Protect the controller with arc
suppressing external circuitry.
This will eliminate high
voltage spikes. Separate the
sensor and power wiring.
Ground heaters
Entered data lost
EEPROM error.
EMI or RFI interference.
Service required.