Functions
3.7 System monitoring
M200D PROFIBUS/PROFINET
52 Manual, 08/2014, A5E01577426A/RS-AA/004
Asymmetry monitoring
Description
Three-phase induction motors respond to slight asymmetries in the supply voltage with a
higher asymmetric current consumption, which causes the temperature in the stator and
rotor windings to increase. In this case, the M200D motor starter protects the motor against
overload by shutting it down.
When the motor is switched on, asymmetry evaluation is suppressed for approx. 0.5 s.
The asymmetry limit is a percentage value by which the motor current is allowed to deviate
in each phase.
Asymmetry exists when the difference between the smallest and the greatest phase current
is greater than the parameterized asymmetry limit.
The reference value for the analysis is the maximum phase current in one of the 3 phases!
You use this device parameter to specify how the motor starter is to behave in the event of
asymmetry:
● Warning
● Trip
Response to asymmetry Trip
• Warning
• Trip
Asymmetry limit 30%
• 30 ... 60%
• 0 = deactivated
Increment: 10%
Asymmetry detected Dependent on parameterization
Asymmetry tripping Trip (asymmetry exists)