Allen Bradley PowerFlex 743

[HAFP]

Is anyone having issues with DC Buss Circuit issues on 753 PowerFlex VFD's?

We have a project where three out of 5 Allen Bradley Power Flex VFD's have failed, since startup in April. Last drive failure had 5 hours of operation on the drive.

L-L-L Voltage 490V. Tech support stating this is causing a high DC Buss Voltage near the trip level of the VFD. Recommends getting utility to lower incoming power as any voltage spikes will fault the VFD's.

New Siemens Surge suppression is not showing any voltage surges. Currently have a power quality analyzer installed trying to determine issue.

Any suggestions would be appreciated.

Thanks

 

[ptonsparky]

Wye or Delta service?

 

[ptonsparky]

IDK about your 753 but line reactors seem to filter POCO spikes on other brands. Some models may come with those as standard. YMMV
490 is well within the operating range of 460-528 indicated in the manual.

 

[HAFP]

The service is a Wye service. The rectifiers are shorting phase to phase. Drive tech has stated the 490V L-L is causing the DC Buss to operate near the fault limit. We are trying to determine if thisis a drive issue or utility issue. Poer company had a meter on for a week and caught one 550V spike. One would think the drive could protect itself.

 

[ptonsparky]

Do you have line reactors?
The drives I worked with usually showed an overvoltage fault and would shut down, not fail.
I do have limited experience and am not even close to an EE.

Do you have an environment issue?

 

[HAFP]

No the drives don't have line reactors. They have shown high DC Buss voltage when not operating, but not an AC over voltage fault. I installed a power quality meter on 7/23 hoping to catch an event before anothe drive bites the dust.

 

[YouConduit!]

AutomationDirect published a white paper on this recently. Let me know if the attachment doesn't work.

 

[HAFP]

Thank you. I appreciate your help. Our Engineer is questioning harmonics on the power supply.

 

[ptonsparky]

AutomationDirect published a white paper on this recently. Let me know if the attachment doesn't work.

I hadn't read this. Thank you.

Wouldn't all these issues result in an error code vs damage to the drive?

Is it possible that a parameter has been set to ignore an overvoltage?

 

[HAFP]

The tech set the parameter lower to protect the drives but the last one blew the reciifier circuit.