Avoiding Overvoltage Tripping; Output Voltage Adjustment/Supply Voltage Correction - Toshiba TOSVERT VF-AS1 Instruction Manual

Even when trip retention selection parameter () is set to , the retry function is enabled by  setting.
During retry the blinking display will alternate between  and the monitor display specified by parameter
monitor display selection parameter .
The number of retries will be cleared if the inverter is not tripped for the specified period of time after a successful retry.
"A successful retry" means that the inverter output frequency reaches the command frequency without causing the
inverter to re-trip.
At the occurrence of a trip, the rotational speed of the motor is measured and, after the motor is restarted, it's speed
is regulated to the speed measured.

6.14.2 Avoiding overvoltage tripping

 : Overvoltage limit operation
 : Regenerative over-excitation upper limit
• Function
These parameters are used to automatically control the output frequency and prevent the motor from
tripping because of overvoltage due to a rise in the voltage in the DC section during deceleration or
constant speed operation. Note that the deceleration time may be prolonged when the overvoltage limiting
function is activated.
Overvoltage limit operation level
Output
frequency
DC
voltage
[Parameter setting]
Title
 Overvoltage limit operation
 Regenerative over-excitation upper limit ~ % [Note]
 Overvoltage limit operation level
Note: 100% corresponds to an input voltage of 200V for 200V models or to in an input voltage of 400V for 400V
models.
If  is set to  (quick deceleration), the inverter will increase the voltage to the motor (over-excitation
control) to increase the amount of energy consumed by the motor when the voltage reaches the overvoltage
protection level, and therefore the motor can be decelerated more quickly than normal deceleration.
If  is set to  (dynamic quick deceleration), the inverter will increase the voltage to the motor (over-
excitation control) to increase the amount of energy consumed by the motor as soon as the motor begins to slow
down, and therefore the motor can be decelerated still more quickly than quick deceleration.
The parameter  is used to adjust the maximum energy that the motor consumes during deceleration, and if
the inverter is tripped during deceleration because of an overvoltage, specify a larger value.
Parameter  serves also as a parameter for setting the regenerative braking level (see section 5.19.).

6.14.3 Output voltage adjustment/Supply voltage correction

: Base frequency voltage 1 (output voltage adjustment)

 : Base frequency voltage selection (supply voltage correction)
• Function
Base frequency voltage 1 (output voltage adjustment)
This parameter is used to set the voltage for the base frequency 1 . It can also be used to prevent the
base frequency over  from being put out even if the voltage is higher than the voltage set is applied.
(This parameter is operative when  is  or . )
Base frequency voltage selection (correction of supply voltage)
The  parameter maintains a constant V/f ratio, even when the input voltage decreases. The torque
during low-speed operation is prevented from decreasing.
Supply voltage correction
Output voltage adjustment
 : Overvoltage stall protection
Function
:Enabled
:Disabled
:Enabled (quick deceleration)
:Enabled (dynamic quick deceleration)
~ % [Note]
Maintains a constant V/f ratio, even when the input voltage fluctuates.
Limits the voltage at frequencies exceeding the base frequency. Note that no limit
is imposed on the output voltage if the supply voltage is not compensated.
F-25
 : Overvoltage limit
operation level
Adjustment range
E6581445
6
Default setting


