Mitsubishi Electric 700 Series Instruction Manual page 157

Operation selection at power failure and instantaneous power failure
When Pr. 162 = 1, 11 (without frequency search)
Power supply
(R/L1, S/L2, T/L3)
Motor speed N
(r/min)
Inverter output
frequency f (Hz)
Inverter output
voltage E (V)
Coasting time
Pr. 57 setting
* The output shut off timing differs according to the load condition.
When Pr. 162 = 0, 10 (with frequency search)
Instantaneous (power failure) time
Power supply
(R/L1, S/L2, T/L3)
Motor speed N
(r/min)
Inverter output
frequency f (Hz)
Inverter output
voltage E (V)
Coasting time
Speed
+
(Pr. 57 )
detection time
* The output shut off timing differs
according to the load condition.
REMARKS
Speed detection time (frequency search) changes according to the motor speed. (maximum 100ms)
When the inverter capacity is two rank or more larger than the motor capacity, the inverter may not start due to overcurrent trip (E.OC ).
If two or more motors are connected to one inverter, the function does not operate properly. (The inverter does not start smoothly.)
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.
NOTE
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 direction detection selection at restarting = "1").
If the frequency search result exceeds the set frequency, the output frequency is limited at the set frequency.
When the wiring length exceeds 100m, select without frequency search (Pr. 162 = "1, 11").
Restart operation at every start
When Pr. 162 = "10 or 11", automatic restart operation is also performed every start, in addition to the automatic restart
after instantaneous power failure. When Pr. 162 = "0", automatic restart operation is performed at the first start after power
supply ON, but not performed at the second time or later.
152
Instantaneous (power failure) time
*
Restart cushion time
(Pr. 58 setting)
*
Restart cushion time
(Pr. 58 setting)
Acceleration time
at a restart
(Pr. 611 setting)
(1) Automatic restart operation selection
(Pr. 162, Pr. 299)
Without frequency search
When Pr. 162 = "1 (initial value) " 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.
REMARKS
This system stores the output frequency and
rotation direction prior to an instantaneous power
failure and restart using the stored value.
Therefore, if the instantaneous power failure time
exceeds 0.2s and the stored value cannot be
retained, the inverter starts at Pr. 13 Starting
frequency (initial value = 0.5Hz) in the starting
direction upon power restoration.
With frequency search
When "0 or 10" is set in Pr. 162, the inverter smoothly starts
after detecting the motor speed upon power restoration.
(The motor capacity should be equal to or one rank lower
than the inverter capacity)
When using the frequency search, perform offline auto
tuning.
(Refer to page 127 for Advanced magnetic flux vector
control, General-purpose magnetic flux vector control and
page 153 for V/F control.)
During reverse rotation, the inverter can be restarted
smoothly as the direction of rotation is detected.
You can select whether to make rotation direction
detection or not with Pr. 299 Rotation direction detection
selection at restarting.
When capacities of the motor and inverter differ, set "0"
(without rotation direction detection) in Pr. 299.
Pr. 299 Setting
9999
0 (initial value)
1
: the rotation direction is detected.
×: the rotation direction is not detected.
Pr. 78 Setting
0 1 2
× ×
× × ×