User Manual

Commissioning

12.4 Commissioning the 3RW40

SIRIUS 3RW30 / 3RW40

Manual, 10/2010, 535199502000 DS 03

109

12.4.6 Current limiting in conjunction with a starting voltage ramp and ramp-up

detection

Current limiting

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The SIRIUS 3RW40 soft starter measures the phase current (motor current) continuously

with the help of integrated current transformers.

The motor current that flows during the startup process can be actively limited by means of

the soft starter. The current limiting function takes priority over the voltage ramp function.

As soon as a parameterizable current limit is reached, in other words, the voltage ramp is

interrupted and the motor is started with the current limiting value until it has started up

successfully. The current limiting function is always active with SIRIUS 3RW40 soft starters.

If the current limiting potentiometer is set to the clockwise stop (maximum), the starting

current is limited to five times the set rated motor current.

12.4.7 Setting the motor current

potentiometer