Appendix A: Troubleshooting - Extech Instruments 96VFL Series User Manual

15. Appendix A: Troubleshooting

Errors
Keypad not functioning
Process value unstable
No heat or output
LEDs and display not lighting up
Process Value changed abnormally
Entered data lost
Probable Cause
Sensor break or sensor not
connected.
A/D converter failure.
Auto Tune time-out error.
Keypad locked.
Keypad defective.
Improper PID tuning.
Fuse blown.
Incorrect wiring.
Heater defective.
No power to controller.
Controller failure.
Electromagnetic (EMI) or
Radio Frequency (RFI)
interference.
EEPROM error.
32
Action
Connect or replace
sensor.
Service required.
Check for EMI or
RFI interference.
Manually tune
control.
Check the 'LOCK'
parameter.
Service unit.
Tune the
controller.
Check wiring and
fuse.
Check heater.
Check power
connection.
Service meter.
Protect the controller
with arc suppressing
external circuitry. This
will eliminate high
voltage spikes.
Separate the sensor
and power wiring.
Ground heaters
EMI or RFI
interference.
Service required.
VFL Series User Manual v2.0 10/20