Mitsubishi Electric FR-D720S SC EC Instruction Manual page 277

Parameter
NOTES
Speed detection time (frequency search) changes according to the motor speed (maximum
100ms).
Frequency search errors can occur if the output capacity of the frequency inverter is one or
more classes higher than that of the motor or if the motor is a special model (e.g. with a fre-
quency rating above 60Hz). If this happens it is possible for overcurrent error messages
(OCT) to be generated during motor acceleration. In such configurations flying restarts are
not possible and the frequency search function should not be used.
At motor frequencies of 10Hz or less the inverter accelerates from 0Hz to the set frequency.
If more than one motor is connected to the inverter in parallel the frequency search on auto-
matic restart does not work correctly and overcurrent error messages (OCT) are likely. In
such configurations deactivate frequency search (set Pr. 162 to "1" or "11").
When reverse rotation is detected when Pr. 78 = 1 (reverse rotation disabled), the rotation
direction is changed to forward rotation after decelerates in reverse rotation when the start
command is forward rotation. The inverter will not start when the start command is reverse
rotation.
When automatic restart operation after instantaneous power failure is activated while the
motor is running at a low speed (less than 10Hz), the motor restarts in the direction prior to
instantaneous power failure without detecting the rotation direction (Pr. 299 "Rotation direc-
tion detection selection at restarting" = 1).
If the frequency search result exceeds the set frequency, the output frequency is limited at
the set frequency.
When using the automatic restart after instantaneous power failure function with wiring
length exceeding below, select without frequency search (Pr. 162 = "1", "11").
Motor capacity
Wiring length
FR-D700 SC EC
0.1K 0.2K
20 m 50 m
Operation selection at power failure
≥ 0.4K
100 m
6 - 127