Siemens SIRIUS 3RW52 - Page 135

Functions
8.2 Current limiting function
SIRIUS 3RW52 Soft Starter
Equipment Manual, 04/2020, A5E35630451002A/RS-AE/005
135
Parameters
Parameter
Description
Current limiting value 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
e
).
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 3RW52 soft starter
("max." position) is 7x the value of the maximum rated operational current for
the 3RW52 soft starter, where this value is identical to 7 times the value of the
maximum rated operational current I
e
that can be set.
This value is independent of the actual rated operational current I
e
of the
motor set at the 3RW52 soft starter.
x Factory setting: 4 x I
e
x Setting range: 1.3 ... 7 x I
e
The setting "max" corresponds to the 7-fold value of the maximum rated
operational current I
e
of the 3RW52 soft starter.
Example
཰
Rated operational current I
e
of the motor: I
e motor
= 29 A
ཱ
Maximum current limiting which can be set at this 3RW52 soft starter: I
max
= 7 x 47 A = 329 A
You will find the scale of the setting element I
e
on the front of the 3RW52 soft starter under
the hinged cover and in the Technical Data (Page 207).