Siemens SIRIUS 3RW51 Equipment Manual page 93

Current path
①
②
③
I Rated operational current during rated operation
e
Parameters
Parameter
Current limiting value
SIRIUS 3RW51 Soft Starter
Equipment Manual, 09/2020, A5E37108631002A/RS-AC/003
Current characteristic with direct-on-line starting without 3RW51 soft starter
Adjustable current limiting value
Voltage ramp
Description
In order to ensure that the drive can reach its rated speed, the minimum
current limiting value that you select must be high enough to generate
sufficient torque in the motor.
A typical value is 3 to 4 times the rated operational current (I
As soon as the current limiting value is reached, the motor is started with
this value until it has reached its rated operating speed. In this case, the
motor starting times may be longer than the maximum parameterizable
ramp-up time.
The maximum possible current limiting value for the 3RW51 soft starter
("max." position) is 7x the value of the maximum rated operational current
for the 3RW51 soft starter, where this value is identical to 7 times the value
of the maximum rated operational current I
This value is independent of the actual rated operational current I
motor set at the 3RW51 soft starter.
•
•
Factory setting: 4 x Ie
Setting range: 1.3 ... 7 x Ie
The setting "max" corresponds to the 7-fold value of the maximum
rated operational current Ie of the 3RW51 soft starter.
Functions
8.2 Current limiting function
).
e
which can be set.
e
of the
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