Mitsubishi Electric FR-A700 Technical Manual page 200

2.5.3 Acceleration/deceleration time [Pr. 7, 8, 16, 20, 21
For the inverter operation, the output frequency is
made to change
deceleration) to prevent the motor and inverter from
excessive stress to reach the set frequency during
start, acceleration, deceleration, stop, etc. when
frequency changes. Linear acceleration/deceleration
has a uniform frequency/time slope.
S-pattern acceleration/deceleration may also be set in
[Pr. 29]. (Refer to page 238)
The acceleration and deceleration times set in [Pr.7, 8,
44, 45, 110 and 111] are the lengths of time required for
the output frequency to change up to the acceleration/
deceleration reference frequency set in [Pr. 20]. The
setting of the acceleration/deceleration time is based
on [Pr. 20 Acceleration/deceleration reference frequency],
independently of whether the operation mode is the
External or PU operation mode.
Acceleration/Deceleration time setting
[Pr. 20 Acceleration/deceleration
reference frequency]
Amount of output
frequency change
[Example 1]
Accelerating to the output frequency of 50Hz in
2.5s when [Pr. 13 Starting frequency] is 0Hz, and
[Pr. 20 Acceleration/deceleration
frequency] is 60Hz (initial setting)
[Pr. 7 Acceleration time]
setting value
[Example 2]
Accelerating to the output frequency of 90Hz in
12.5s when [Pr. 13 Starting frequency] is 0Hz, and
[Pr.
20 Acceleration/deceleration
frequency] is 90Hz
[Pr. 7 Acceleration time]
setting value
linearly (linear acceleration/
=
Acceleration/deceleration
time for the amount of
output frequency change
reference
60Hz
=
2.5s = 3.0s
50Hz
reference
90Hz
=
12.5s = 12.5s
90Hz
* , 44, 45, 110
(*[Pr. 110, 111] are not available for
(*[Pr. 21 110, 111] are not available for
(*[Pr. 147] is available for only
The minimum input increments of the acceleration/
deceleration time setting are factory-set to 0.1s.
(When the value is set from the operation panel with
[Pr. 21 = 0], the setting increments are 1s for the setting
of 1000s or more.)
By changing the setting to [Pr. 21 = 1], the acceleration/
deceleration time can be set in increments of 0.01s.
(In this case, the maximum setting is 360s. When the
value is set from the operation panel with [Pr. 21 = 1],
the setting increments are 0.1s for the setting of 100s
or more.)
Note that changing the [Pr. 21] setting changes the
acceleration/deceleration time setting. When [Pr. 21 =
0] and [Pr. 7 = 5s], and if the setting is changed to [Pr.
21 = 1], the acceleration/deceleration time setting will
change to [Pr. 7 = 0.5s].
The setting conditions of the related functions
(parameters) are indicated in the table in the next
page. The initial settings of the acceleration/
deceleration times are temporary and should be
changed to actually
operable values varies according to the load
conditions (load torque and load GD2 reflected back to
the motor shaft) and motor conditions (motor torque
capability and motor GD2).
Refer to page 487 for the way of calculating the
acceleration/deceleration time according to the load
conditions and motor conditions.
When the load conditions are unknown, perform the
operation and determine the acceleration/deceleration
time which does not activate stall prevention.
[Pr.20]
(60Hz)
Acceleration [Pr.7]
time [Pr.44]
[Pr.110]
234
PARAMETER
* , 111 * , 147 * ] common
(common)
F700
operable values. Actually
Running
frequency
Time
Deceleration
[Pr.8]
time
[Pr.45]
[Pr.111]
.)
E700
.)
D700
.)
E700