Asymmetry Monitoring - Siemens SIRIUS M200D Manual

3.7.2

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.
Note
When the motor is switched on, asymmetry evaluation is suppressed for approx. 0.5 s.
Asymmetry limit
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!
Response to asymmetry
You use this device parameter to specify how the motor starter is to behave in the event of
asymmetry:
● Warning
● Trip
Settings
Response to asymmetry
Asymmetry limit
(Motor Starter ES)
Note
Individual parameters can only be set using Motor Starter ES.
M200D AS-Interface Standard
Manual, 08/2014, A5E02548958A/RS-AA/004
Device parameter
3.7 System monitoring
Default setting
Trip
•
•
30%
•
•
Increment: 10%
Functions
Setting range
Warning
Trip
30 to 60%
0 = deactivated
51