Mitsubishi Electric FR-A700 Technical Manual page 199

(3) Starting frequency [Pr. 13]
Set the frequency at a voltage output start, which will be
reached when the start signal is switched ON across
terminals STF (or STR).
Starting frequency is used with [Pr. 0 Torque boost] to
mainly adjust the starting torque. The rise in starting
frequency not only raises the corresponding output
voltage but also increases the starting current along with
the starting torque. The following value is recommended
as a guide to setting the starting frequency to keep the
starting current less than the stall prevention operation
current.
0.5Hz (initial value) for general application. 3Hz for a lifter
and lowering device, etc. When the lifter and lowering
device is started at a low starting frequency, the load may
slip down due to insufficient starting torque as soon as
the mechanical brake is released. The inverter cannot
be started if the frequency setting is less than the
starting frequency.
Output
frequency(Hz)
60
Setting
range
[Pr.13]
0
STF ON
[Pr.] Name Initial Value
Starting
13
frequency
Holding time at a
571
start
2.5.2 Frequency jump [Pr. 31 to 36]
If motor mechanical resonance occurs, this function allows the
running frequency, at which the mechanical resonance has
occurred, to be avoided (jumped). During acceleration/
deceleration, the running frequency within the set area is valid.
Frequency jump is not performed if the initial value (9999) is set.
[Pr.] Name
31 Frequency jump 1A
32 Frequency jump 1B
33 Frequency jump 2A
34 Frequency jump 2B
35 Frequency jump 3A
36 Frequency jump 3B
Set
frequency (Hz)
Frequency jump
[Pr.36]
[Pr.35]
[Pr.34]
[Pr.33]
[Pr.32]
[Pr.31]
Frequency setting signal
Time
Setting Range
0.5Hz 0 to 60Hz
0.0 to 10.0s
9999
9999
common
(common)
Initial Setting
Value Range
0 to 400Hz,
9999
9999
Set
frequency (Hz)
[Pr.32] = 38
[Pr.31] = 32
(4) Start-time hold function [Pr. 571]
For smooth motor driving at start, this function holds
the output frequency set in [Pr. 13 Starting frequency]
during the period set in [Pr. 571] to perform initial
excitation for a motor.
At switching between forward rotation and reverse
rotation, the starting frequency is valid but the start-
time hold function is invalid.
When [Pr. 13 = 0Hz], the starting frequency is held at
0.01Hz.
For example, setting brake opening delay time for
mechanical brake in [Pr. 571] limits current when brake
is closed, makes the motor driving smooth at brake
opening.
Output
frequency (Hz)
60
Setting
range
[Pr.13]
0
STF
Description
Frequency at start can be set in the range 0 to 60Hz.
You can set the starting frequency at which the start signal is turned ON.
Set the holding time of [Pr. 13 Staring frequency].
Holding function at a start is invalid
(1) Frequency jump area
Up to three areas may be specified. Areas may be
specified in any order.
(2) Frequency jump range
The range is determined by setting the top and
bottom points to be avoided, not a jump value.
(3) Jump point
In the jump range, set the jump point at which
operation is performed.
If the jump range setting is between 32 and 38Hz, for
example, determine at which frequency, 32Hz or 38Hz,
the operation is to be performed when the frequency
setting signal is within the above range. This jump
point is defined by the frequency set in Frequency
jump 1A, 2A or 3A ([Pr. 31], [Pr. 33] or [Pr. 35]).
Set
frequency (Hz)
Frequency setting signal
233
PARAMETER
Time
[Pr.571] Setting time
ON
[Pr.31] = 38
[Pr.32] = 32
Frequency setting signal
2