Section VII Test runing and application
24
Current limit starting mode is generally used for a strictly limited starting
current requirements of the occasion.
7-2-2
Voltage ramp start model
When P9 setting item is 1, start
mode is for this mode.
Chart 7.2 shows the output voltage
waveform as voltage ramp start voltage
waveform. U1 is the initial starting
voltage of starting, when the motor start,
the motor current does not exceed 400%
of rated range, the output voltage of soft
starter quickly rise to U1, then the output
voltage gradually increase by the start
parameters setting, the motor is in smooth acceleration according to voltage
continuously rise, when the voltage reach the rated voltage Ue, the rated motor speed,
bypass contactor act, starting process is complete.
Starting time t is based on standard load obtained in the standard experimental
conditions, control parameters, PR5200(C) series soft starter is based on this
parameter benchmark, by controlling the output voltage, make the motor speed up
in a smooth start-up process, not a mechanical control, regardless of time t.
Acceleration is smooth. In view of this, when the load is light, set the start time often
less than the starting time, as long as a smooth start is normal.
In general, the voltage ramp start mode is suit to not strict starting current
requirement and strict demanding of a
smooth start of the occasion.
7-2-3
Kickstart mode
P9 setting item set to 2 or 3, starter
model is for this mode.
Chart 7.3 and Chart 7.4 shows the
kickstart mode waveform of the output.
In some heavy load situations, due to
mechanical effects of static friction,
when it can not start the motor, you can
use this start mode. At the start, imposing
a high fixed voltage to the motor first
and last for a limited period of time, to
T
U
Ue
U1
0
t
Chart
7.2
T
C
Un100%
U1
0
100ms
T
C
Un100%
U1
0
100ms
Chart
7.4
Chart
7.3
