Braking Circuit Fault; Over Speed - Mitsubishi FREQROL-SFJ Maintenance Manual

(7) BRAKING CIRCUIT FAULT

This alarm occurs if the braking circuit does not func-
tion properly.'
Cause
Trouble with card
SFJ-CA1
Trouble with con- 'If the same alarm occurs
unit.
.

(8) OVER SPEED

This alarm appears if motor speed exceeds 115% of the
rated speed.
Cause
Parameter setting
improper
Speed detection
signal distorted
by noise
Checkup
Replace the card SFJ-CA1
with a new one to check.
again with a new card SFJ-
the control unit is
likely to be defective.
Checkup
Observe the signal from CH31
and 32 (common CH23) of SFJ-
using an oscilloscope,
Check if shielding of cable
'between motor and CON2 is
Remedy
Replace the card
Replace the con-
trol unit.
Remedy
If the setting is
too low, speed de-
tection range is
narrow (15%) and
therefore this
alarm is likely to
occur.
Increase setting
of maximum speed
parameter ITSPI
Use a continuous
cable to assure
continuous shield-
ing.