YASKAWA U1000 Series Technical Manual page 199

Speed Search from the Direction Command (0.0 ≤ Momentary Power Loss Time t < b3-50)
When time t from the momentary power loss to recovery is shorter than the setting value of b3-50, Speed Search is
performed in the direction specified by the direction command. The deceleration time set in b3-52 is used for the search
frequency and the setting value of the frequency reference is used as the starting search frequency.
Figure 5.19
Momentary power loss time t
0
Continuous Baseblock (b3-50 ≤ t < b3-51)
When time t from the momentary power loss to recovery is between the times set for b3-50 and b3-51, operation will not
be restarted and the baseblock will continue. The drive will stay in baseblock for the time set in b3-51 even after restoring
power. After the time set in b3-51 passes, Speed Search starts in the opposite direction of the direction command. The
deceleration time in b3-53 is used for the search frequency and the setting value of the frequency reference is used as the
starting search frequency.
Figure 5.20
Power supply voltage
Momentary power loss time t
0
Normal operation
Search in progress
Speed Search in Direction Opposite to Direction Command (b3-51 ≤ t)
When time t from the momentary power loss to recovery exceeds the setting value of b3-51, Speed Search is performed
in the opposite direction of the direction command. The deceleration time in b3-53 is used for the search frequency and
the setting value of the frequency reference is used as the starting search frequency.
YASKAWA ELECTRIC SIEP C710636 02B YASKAWA U1000 Technical Manual
Forward operation
Normal operation b3-50
b3-51
Search in progress
t
Figure 5.19 Speed Search from Forward Run Command (0 ≤ t < b3-50)
Forward operation
b3-50
b3-51
Figure 5.20 Continuing Baseblock (b3-50 ≤ t < b3-51)
b3-52
b3-53
t
5.2 b: Application
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