Automatic Restart After Instantaneous Power Failure / Flying Start With A Pm Motor - Mitsubishi Electric 800 Series Instruction Manual (Function

16.8
Automatic restart after instantaneous power failure
/ flying start with a PM motor
PM PM PM
The inverter can be restarted without stopping the motor operation.
When the automatic restart after instantaneous power failure function is selected, the motor driving is resumed in the following
situations:
• When power comes back ON during inverter driving after an instantaneous power failure
• When the motor is coasting at start
Pr. Name
57
Restart coasting time
A702
Automatic restart after
162
instantaneous power
A700
failure selection
611 Acceleration time at a
F003 restart
 Selection of restart operation (Pr.162)
• At a power restoration, the encoder detects the motor speed by a frequency search so that the inverter can re-start
smoothly.
• The encoder also detects the rotation direction so that the inverter can re-start smoothly even during the reverse rotation.
• When "10 (or 11)" is set in Pr.162, a restart operation is performed at each start and automatic restart after instantaneous
power failure. When "0 (or 1)" is set in Pr.162, a restart operation is performed at the first start after a power-ON, and from
the second power-ON onwards, a start from the starting frequency is performed.
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)
Speed
Coasting
detection
+
time (Pr.57)
time
* The output shut off timing differs
according to the load condition
NOTE
• Because a DC injection brake is applied instantaneously at speed detection during a restart, the speed might drop if the
moment of inertia (J) of the load is small.
• Restart operation with reduced voltage is not available for PM sensorless vector control.
• A protective function may be activated for some motor models or at certain running speeds, disabling restarting.
 Restart coasting time (Pr.57)
• Coasting time is the time from the motor speed detection to the restart operation start.
• To enable restart operation, set "0" (no coasting time) in Pr.57 Restart coasting time. Generally, this setting does not
interfere with inverter operation.
Initial value Setting range
0
9999 0.1 to 30 s
9999
0, 1
0
10, 11
0 to 3600 s
9999
9999
*
Acceleration time
at a restart
(Pr.611 setting)

16.8 Automatic restart after instantaneous power failure / flying start with a PM motor

Description
No delay
Set the delay time for the inverter to perform a restart after restoring
power due to an instantaneous power failure.
No restart
Frequency search only performed at the first start
Frequency search at every start
Set the acceleration time to reach Pr.20 Acceleration/deceleration
reference frequency at restart.
Standard acceleration time (for example, Pr.7) is applied as the
acceleration time at restart.
16. (A) Application Parameters
11
12
13
14
15
16
17
18
19
20
449