Multiple Manufacturing Buildings VFDs tripping due to Overvoltage 1

[StruggleEngr]

Hello All,

I am a field engineer at a complex that serves multiple manufacturing buildings. My group is responsible for the 12.47kV overhead distribution to the building service entrance equipment, including the transformer (Delta-Wye XFMR).

Three manufacturing buildings are experiencing overvoltage trips on their AB PowerFlex 525 VFDs. Since the trips are several buildings around the same time (the morning), we got called up because there is a concern for utility power quality issues.

The overvoltage fault could be several possible issues from building transformer, harmonics, transient voltages, etc. I am reaching out to the collective to get ideas on what I should check and bounce some of my team's ideas. I think a lightning arrester is failing on one of the 12.47kV distribution poles, and there is an intermittent ground fault. But I am unsure how an intermittent ground fault would cause an overvoltage trip on the VFDs.

Thanks!!

 

[System Protection]

Monitor the incoming voltage with a power quality meter.

Set up triggers to capture voltage spikes if your meter is capable.

I'm also curious if the customer has line reactors on their VFDs.

I've seen voltage spikes that didn't seem to affect anything except the VFD.

I had a line reactor installed on the VFD and it "fixed" the issue. (Easier than trying to get POCO involved)


Also here is an article that touches on possible voltage rise for SLG faults.

https://voltage-disturbance.com/pow...swell,overvoltage condition if not mitigated.

 

[waross]

I once had an ongoing disagreement with our general manager over end user voltages.
The line crew put up a new transformer on the wrong tap.
The manager monitored the monthly total KWHrs on each transformer.
If the consumption on a transformer decreased, relative to the other transformers, the line crew would start to look for signs of power theft.
The manager noticed that the consumption on the new transformer had increased and asked me to look into it.
I found that the voltage was high by about the same percentage as the increase in consumption.
I suggested that the transformer tap be lowered, but the manager wanted to keep the extra revenue and would not ookay a change.
In areas where deregulation has led to wire service providers, the service providers tend to keep the voltage at the high end of the spectrum to maximize through-put and revenue.
Some times the voltage drifts too high.
You may ask the utility for a copy of the saved parameters on the revenue meter.
Many electronic meters have the ability to save the maximum value in each 15 minute block.
Voltage, current, KVAR, max KVA, demand KW, max KW, KVARHrs, KWHrs.
I worked with a friendly utility, and If I supplied a floppy disk, and a couple of 2 liter bottles of Pepsi, I would get my floppy back with about 2 months of data, in 15 minute intervals.
That helped my solve more than one problem.
(If 2 x 2 liters of Pepsi is bribery, then I am guilty.)




--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[iop95]

More details would be helpful to avoid making unnecessary assumptions.
-voltage input and VFD power
-error arise when drive is on STOP or RUN status?
-may check on log latest 10 DC bus voltages values at faults
-DC bus regulation is activated?