Setting The Acceleration And Deceleration Time; Increasing Torque - Toshiba VFS5 Series Operation Manual

Applicable parameters: Automatic acceleration and deceleration AU1
drive, and manual setting.
There are two methods of setting the acceleration and deceleration time: Automatic
setting of the acceleration and deceleration time by the drive, and manual setting.
1) Automatic acceleration and deceleration time setting
To select automatic acceleration and deceleration time setting, set the AUI value to 1.
Note:
When automatic acceleration and deceleration time setting is selected, the acceleration and
deceleration time is always varied according to the load conditions. If the machine requires a
predetermined acceleration and deceleration time, use the manual acceleration and deceleration
time setting function.
2) Manual acceleration and deceleration time setting
Set the AUI value to 0. Then, set the ACC and dEC values to the desired acceleration
time and deceleration time, respectively.
Maximum frequency
fH
Applicable parameters: Automatic torque boost aU2
The motor torque can be increased by raising the inverter output voltage. There are two methods of
raising the output voltage: 1) automatic voltage raising by the drive and 2) manual voltage raising.
Note:
If the output voltage is increased too much, the drive may trip overcurrent. This may lead to drive and/or
motor damage.
1) Automatic torque boost and improving the speed accuracy:
Set the AU2 value to 1. The torque is automatically increased. To increase the speed
accuracy, set the AU2 value to 3. If operation is not stable when AU2 is set to 2 or 3,
set aU2 to 1, and the operation will become stable.
2) Increasing drive output manually:
Set the AU2 value to 0 and increase the ub value. Start with a value of 3 and increment by units
pf one. Chect for low current and smooth operation at each setting and select the best value.
TOSHIBA

Setting The Acceleration and Deceleration Time

Acceleration time
acc

Increasing Torque

aU2, and torque boost ub
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AU1, acceleration time by the
Deceleration time
dec
ub.