Troubleshooting; General Information; Was Any Alarm Displayed On The Controller? - Mitsubishi FREQROL-SFJ Maintenance Manual

8.1 General information

If any trouble occurs with the control system, perform the
preliminary check described below and then proceed to the
troubleshooting described later.
The following preliminary check is very important when you
consult with service engineer.
Preliminary check:

1. Was any alarm displayed on the controller?

If yes, identify the cause of alarm.
Also examine previous alarms through the LED readout in
2. If fuse was blown out, identify the phase in which the
blown out fuse was used (control circuit power supply
fuse).
3. Is the trouble or failure reproducible?
4. Are ambient temperature and panel inside temperature nor-
mal?
5. When the trouble occurred (during accelerat
ration, or steady-speed operation)?
What was the speed?
6. Is direction of rotation correct?
7. Did instantaneous power failure not occur?
Does the same trouble occur in a specific operation, or
when a specific command is given?
9. How frequently occurs the trouble?
10. Does the trouble occur when load is applied, or when load
is removed?
11. Was any part replaced or any provisional remedy done?
12. How many years have been used the control system?
ion, or dece le-