SJ700
2
Inverter
Configur
ing Dr
iv
e
P
a
ra
met
e
rs
3–21
Jump Frequencies –
Some motors or machines exhibit resonances at particular speed(s),
which can be destructive for prolonged running at those speeds. The inverter has up to three
jump frequencies
as shown in the graph. The hysteresis around the jump frequencies causes the
inverter output to skip around the sensitive frequency values.
Acceleration
Pause Function
The acceleration pause function can be
used to minimize the occurrence of
over-current trips when accelerating
high inertia loads. It introduces a dwell
or pause in the acceleration ramp. You
can control the frequency at which this
dwell occurs (A069), and the duration
of the pause time (A070). This function
can also be used as an anti-windmilling
tool, when the load might have a
tendency to drive the motor in a reverse
direction while the inverter is in a Stop mode. Initiating a normal acceleration in such a situa-
tion may result in over-current trips. This function can be used to keep the inverter output
frequency and voltage at low levels long enough to bring the load to a stop, and commence
turning in the desired direction before the acceleration ramp resumes. See also
“DC Braking
Settings” on page 3–18
.
Frequency command
Jump frequencies
Output
frequency
Hysteresis values
A067
A065
A063
A064
A064
A066
A066
A068
A068
Func.
Code
Name/
Description
Range and Settings
Defaults
Run
Mode
Edit
Lo Hi
FEF2
FE2
(EU)
FUF2
FU2
(USA)
FF2
F2
(Jpn)
A063
A065
A067
Jump (center) frequency setting
0.00 to 400.0 (Hz);
model -4000HFx2 is 0.00 to 120.0 (Hz)
0.00
0.00
0.00
✘ ✔
Up to three output frequencies can be defined for the output to jump past to
avoid motor resonances (center frequency)
✘ ✔
A064
A066
A068
Jump (hysteresis) frequency width
setting
Range is 0.0 to 10.0 Hz
0.50
0.50
0.50
✘ ✔
Defines the distance from the center frequency at which the jump occurs
✘ ✔
Accel pause
period
Output
frequency
A070
A069
Set frequency
t
0
Func.
Code
Name/
Description
Range and Settings
Defaults
Run
Mode
Edit
Lo Hi
FEF2
FE2
(EU)
FUF2
FU2
(USA)
FF2
F2
(Jpn)
A069
Acceleration pause frequency setting
0.00 to 400.0 (Hz);
model -4000HFx2 is 0.00 to 120.0 (Hz)
0.00
0.00
0.00
✘ ✔
A070
Acceleration pause time setting
0.0 to 60.0 (seconds)
0.0
0.0
0.0
✘ ✔