Hi All,

We are facing problem of  undervoltage trip in Siemens Micromaster 440. The input voltage are in the range i.e. 384 VAC, it trips on undervoltage. Sometime it operates and sometimes not. 

can somebody please guide regrading the issue.

DRive MLFB?

Motor details?

Control mode?

Supply voltage?

check the power module and the supply voltage

Hi

Some times tripping and some times not tripping indicates your incoming AC voltage is not stable may be fluctuating. Do you have 3 phase power recorder in incoming. Does the drive has built in integral filter. What is the value you see in r0026 (DC voltage).

If your dirve name plate is 380-480 V VFD with integral filter should not effect till  - 10% voltage dips

Regards,

Vijay

masimn

Hi All,

We are facing problem of  undervoltage trip in Siemens Micromaster 440. The input voltage are in the range i.e. 384 VAC, it trips on undervoltage. Sometime it operates and sometimes not. 

can somebody please guide regrading the issue.

 My question is did you facing same problem some time or now when you energized your vfd still  low voltage fault coming . if still low voltage fault then two things one check the input all phase to phase voltage if input voltage normal then check inside VFD dust or dirt if there is dust and dirt on control card blower it it means your vfd need maintenance otherwise possible reason primary side rectifier unit module open circuit it means ac to dc rectifier module open one of 6 diodes .

check also your drive input voltage parameters.