Stopping Acceleration/Deceleration - Hitachi WJ Series User Manual

Chapter 9
9.3.3

Stopping Acceleration/Deceleration

 Since high torque is required to start the motor, how to stop acceleration temporarily until the
Q
motor rotation follows the command?
 How to stop the deceleration until the motor rpm drops sufficiently to allow the deceleration to
completely stop the motor?
 The acceleration/deceleration hold function allows you to temporarily stop
A
acceleration/deceleration, holding the current frequency to continue operation at a constant
speed.
 The hold function is effective for mechanical systems that have a large moment of inertia.
 The acceleration hold function is useful in cases such as when you wish to prevent an
overcurrent trip upon startup by waiting until any motor slip is minimized. The deceleration hold
function is useful in cases such as when you wish to prevent an overvoltage trip during
deceleration by waiting until any motor slip is minimized.
 There are two methods to stop acceleration and deceleration, which can both be used together.
- Automatically stopping at a predetermined frequency and stop time.
- Stopping according to an input terminal function.
 If the acceleration/deceleration hold function is activated when "Acceleration/deceleration
!
curve selection [A097]/[A098]" is set to a value other than " Linear (00)", the current
acceleration/deceleration pattern is cleared. As soon as the hold function is deactivated, the
pattern is recalculated and acceleration/deceleration is performed again.
Code
Acceleration stop
[A069]
frequency
Acceleration stop
[A070]
time
Deceleration
[A154]
stop frequency
Deceleration
[A155]
stop time
[C001]
Input terminal
to
function
[C007]
■ Applying the hold function at a predetermined set frequency and set time
 Once the set frequency command value is reached during acceleration or deceleration, the
acceleration/deceleration is paused for the set length of time. Separate hold frequency and
hold time settings can be used for both acceleration and deceleration.
■ Applying the hold function using the [HLD] input terminal
 When the [HLD] input terminal turns on, the acceleration/deceleration is stopped.
Item
Sets the stop frequency during acceleration.
Sets the stop time during acceleration.
Sets the stop frequency during deceleration.
Sets the stop time during deceleration.
Acceleration/deceleration disable [HLD]:
When this signal is turned on, the acceleration/
deceleration is stopped. When it is turned off,
the acceleration/deceleration is restarted.
Output frequency [Hz]
[A154]
[A069]
[A070]
Output frequency [Hz]
[HLD]
ON
9-3-4
Description
[A155]
OFF
ON
Inverter Functions
Data
0.00 to 590.00 (Hz)
0.0 to 60.0 (s)
0.00 to 590.00 (Hz)
0.0 to 60.0 (s)
83
Time [s]
Time [s]