ABB ACS800-07 VSD fault on ramp up between 98 and 100%

[Ralphs_coal]

Hi hoping someone can assist me with current issue I am experiencing with an ABB drive.

Problem I’m experiencing is a ABB drive supply a large fan cannot reach 100% speed without tripping on supply loss with no fault indication.

I have 2 drives operating exact same spec fans and only get issues with one drive when it has been off for extended periods no issues with other drive.

When ramping from 98-100% drive will trip, I have tried everything code traps, service support ABB, changed hardware. Annoying thing is sometimes drive flukes it and will reach 100% and as drive is running non stop once it hits 100% it stays that way until next maintenance outage! I’m currently running drive at 98% after maintenance period.

I am at a loss and if any experts could assist it would be hugely appreciated

 

[joseph_e2]

Once it's warmed up, can you bring it back up to 100%? This is a weird one...

 

[Ralphs_coal]

Unfortunately not, ran at 95% for 24 hours then attempted ramp to 100 same issue.

I agree very weird and zero answers from ABB service team.

 

[iop95]

May you add more details?
VFD nominal power, nominal input voltage, power supply type (direct to grid/tansformer/etc), acceleration ramp time?
Motor nominal power/nominal speed?
So, VFD cut output voltage without any message when try to increase speed above 95% of what? Nominal motor speed / max reference frequency set on VFD / or any other speed?

 

[BryanG]

The obvious answer if it is tripping on supply loss, is that it looses the supply! With a centrifugal fan that last 2% increase in speed will mean the drive pulls a chunk more power. See the Third Fan Law in the link below:

Understanding the Basic Fan Laws - Axair Fans

Understand the basic fan laws in our comprehensive worked example for pressure, power and the volume of air. Visit our news for full details.

www.axair-fans.co.uk

Log the supply voltage over the fan speed range.