Drive power query
Drive power query
(OP)
Hi gents,
We have a number of ABB AC drives in my mill. Having had a recent shut for 4 weeks we are now experiencing a number of drive related problems a few days after starting up
eg: Power Caps blowing, control cards being damaged and needing to be changed etc.
With consistant powering down and then powering up again on the drives will the capacitors take excesive load due to charging & discharging and then cause them to fail?
Should a UPS on the supply reduce the possibility of similar issues reoccuring?
Has anyone experienced similar issues in the past?
We have a number of ABB AC drives in my mill. Having had a recent shut for 4 weeks we are now experiencing a number of drive related problems a few days after starting up
eg: Power Caps blowing, control cards being damaged and needing to be changed etc.
With consistant powering down and then powering up again on the drives will the capacitors take excesive load due to charging & discharging and then cause them to fail?
Should a UPS on the supply reduce the possibility of similar issues reoccuring?
Has anyone experienced similar issues in the past?





RE: Drive power query
RE: Drive power query
RE: Drive power query
In addition, there may be a build up of dust or other contaminants on the boards and caps that attracts a little moisture when cold and then flashes when the power comes on.
Another issue is that after a shutdown, with the plant not running the power tends to be above normal when the drives are energized.
I suspect a combination of all of the above.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Drive power query
the drives are in a controlled environment, which includes air conditioning, air purification and room pressurization.
We monitored the power quality on start up and there were no surges which occurred, while the supply was within the required range.
RE: Drive power query
In manuals
Unbalanced or ungrounded distribution systems
If phase to ground voltage exceeds 125% of normal line to line voltage . .......
Either clip the caps off the ground or correct the power unbalance or check your grounding.
Did you have power worked on during the shutdown?
RE: Drive power query
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RE: Drive power query
VFD's do not last forever and it is possible coincidence that these are failing now. If they are 10+ years old then maybe it is time for an upgrade.
RE: Drive power query
Our ABB caps were provided with fuses [Is-Limiter] so the blowing was avoided. See:
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RE: Drive power query
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The phenomenon was minimized by correct grounding, employing optocouples and surge suppressors.