E6581531
F-25
6
During retry the blinking display will alternate between
TVT[
and the monitor display specified by parameter
monitor display selection parameter
H
.
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.
6.15.2 Avoiding overvoltage tripping
H
: Overvoltage limit operation
H
: Regenerative over-excitation upper limit
H
: Overvoltage limit constant
H
: Overvoltage limit operation level
• 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
DC
voltage
Output
frequency
H
: Overvoltage stall protection
[Parameter setting]
Title
Function
Adjustment range
Default setting
H
Overvoltage limit operation
:Enabled
:Disabled
:Enabled (quick deceleration)
:Enabled (dynamic quick deceleration)
H
Regenerative over-excitation upper limit
~
% [Note1]
H
Overvoltage limit constant [Note2]
:Automatic,
~
ms
H
Overvoltage limit operation level
~
% [Note1]
According to voltage
class
⇒
Refer to
page K-43.
Note1: 100% corresponds to an input voltage is as follows.
Note2:The filter time constant of the overvoltage limitation can be adjusted.
The parameter is effective at only V/F control mode(
RV
=0,1,5).
When
V[R
is set to
equal 500V,
equal 575V and
equal 690V.
If
H
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
H
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
H
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
H
serves also as a parameter for setting the regenerative braking level (see section 5.19.).
6.15.3 Output voltage adjustment/Supply voltage correction
XNX
: Base frequency voltage 1 (output voltage adjustment)
H
: 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
XN
. It can also be used to prevent the base
frequency over
XNX
from being put out even if the voltage is higher than the voltage set is applied. (This parameter
is operative when
H
is
or
. )
Base frequency voltage selection (correction of supply voltage)
The
H
parameter maintains a constant V/f ratio, even when the input voltage decreases. The torque during
low-speed operation is prevented from decreasing.
