Mitsubishi Electric FR-A700 Instruction Manual page 522

Operation selection at power failure
● Without frequency search
When Pr. 162 = "1" or "11", automatic restart operation is performed in a reduced voltage
system, where the voltage is gradually risen with the output frequency unchanged from prior
to an instantaneous power failure independently of the coasting speed of the motor.
For real sensorless vector control, output frequency and voltage before instantaneous power
prior to an instantaneous power failure independently of the coasting speed of the motor.
Automatic restart without frequency search (Pr. 162 = 1/11)
(L1, L2, L3)
frequency
The output shut off timing differs according to the load condition.
(L1, L2, L3)
frequency [Hz]/
voltage [V]
The output shut off timing differs according to the load condition.
NOTE This system stores the output frequency prior to an instantaneous power failure and incre-
ases the voltage. Therefore, if the instantaneous power failure time exceeds 0.2s, the inver-
ter starts at Pr. 13 "Starting frequency" (initial value = 0.5Hz) since the stored output
frequency cannot be retained.
6 - 342
Power failure
Power
supply
Motor
speed
[r/min]
Output
[Hz]
Output
voltage
[V]
Coasting time
Pr. 57 Restart
Power failure
Power
supply
Motor
speed
[r/min]
Output
Output
Coasting time
Pr. 57
Fig. 6-159:
Under V/f control or advanced magnetic flux
vector control
cushion time
Pr. 58
Abb. 6-160:
Under real sensorless vector control
Parameter
I000647C
I001604E