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Chapter 7 Test runing and application
24
the impact of high current, pay attention that, this soft start current limit is a percentage calculated
on the basis of starting current limit value.
7-3-2
Free stop mode
Item P2 is set to 0, set stop mode for this mode.
In this stop mode, when the soft starter receive the stop command, immediately disconnect the
bypass contactor and ban soft starter thyristors voltage output, motor gradually stop as load inertia.
In the situation of one drive two(more) wiring, should set soft starter stop mode as this, in order to
avoid of the phase fault reporting when output switching.
Under normal circumstances, if not necessary soft stop, stop mode should be free stop model,
to extend the life of the soft starter.
As stop model completely ban the instantaneous output, can avoid an instantaneous high-
current impact in special applications.
7-4. Special application
7-4-1.Motors in parallel Start:
If not exceed the rated power limit of the soft starter, the motor can be connected in parallel
(motors sum current can not exceed the power of soft starter, the type selected depending on the
application rated current), but at this time should provide additional thermal protection devices for
each motor.
7-4-2.Two-speed motor start:
PR5200(C) series soft starter can start with two-speed motor, before changing from low speed
to high speed, must be solved by delayed magnetic period, to avoid a very large reverse current
between the line and the motor.
7-4-3.Long cable:
As the resistance of the cable causes, a very long motor cables could cause voltage landing, if
the voltage drop is very obvious, it will affect the current consumption and starting torque, when
choosing motor and soft starter, must consider this.
7-4-4.Soft starters parallelled with the same one power line:
If in a power line, installed several soft starters, should install the input reactor between the
wiring of the soft starter and transformer, to the middle of the line should be . Reactor should be
installed between each feeder circuit breaker and soft starter.
7-4-5.Surge protection Device (SPD) application:
In the applications which may suffer from lightning or other causes that lead to overvoltage,
overcurrent, surge interference, should consider installing a surge protector, detailed application
methods instructions, refer to POWTRAN company "surge protector (SPD)" Product sample or
other relevant data.
7-5. Application examples
Under different load conditions, parameter settings for example shown in table 7.1. Data in
the table is only for reference, should be adjusted according to actual situation
Table 7.1
Type of load
Start time
(seconds)
The initial
voltage
Voltage starting
(maximum current
limit)
Limit Start
Ball
30
60%
4
4.5
Fans
26
30%
4
3.5
Centrifugal pump
16
40%
4
2.5
Piston compressor
16
40%
4
3
Summary of Contents for PR5200 Series
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