Siemens SIRIUS 3RW55 - Asymmetry

Functions
7.8 Asymmetry
SIRIUS 3RW55 soft starter
Manual, 08/2018, A5E35630887002A/RS-AB/002
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7.8
Asymmetry
Operating principle
In certain phases of the motor, an asymmetrical current consumption can cause a reduction
in power or damage to the motor. Possible causes for this are a different line or phase
voltage or an already damaged motor winding. The asymmetry monitoring monitors the 3
phase currents and issues a warning or switches the motor off at parameterizable limits.
Parameters
Parameters
Description
Asymmetry limit warning If the asymmetry exceeds this limit, a warning is generated and
the motor is not switched off. The parameter value "0" (factory
setting) deactivates the limit.
• Factory setting: 0%
• Limit: 10 ... 60%
• Increment: 5%
Asymmetry limit error If the asymmetry exceeds this limit, a fault is generated and the
motor is switched off. The parameter value "0" deactivates the
limit.
• Factory setting: 30%
• Limit: 10 ... 60%
• Increment: 5%