Inverter Unit of VFD Burnt

Perhaps just an independant failure of VFD-1. Are any fault codes available on the drive? What does it do now?

It cannot hurt to have the earth wire in place, Check the cooling fans if you have, and the heat sink, to see if there is a build up of dirt on the surface, that prevents heat conduction. Give it all a good clean while its not working.

Look and the instruction manual and check as said in the other reply, the fault codes/fault display. I also suspect over heating of the inverters rather than an external fault causing the failure.

Good that you have checked the motors and cables, I hope you disconnect the motor cable from the VFD before you meggered.

I think you can forget about any power fluctuation as it would have affected both VFD's not just one. You may also want to check the inverter control boards, if there are test points check out the signals and the output to the inverters.

don't forget to let us know what you find

If there was no obvious reason for failure (e.g contamination is the most common reason) then I suppose it may be down to the VFD.

If so,

1. Faulty component or end of life (how long has this been installed?)

2. Temperature (heat sealing compound not sufficient leading to hotspots then failure of device

3. Misfire by control circuit causing short circuit current

Check all motor connections thoroughly too but I would advise an expert repair where the sequencing and calibration can all be assured.

Obviously, the ground connection should be fixed but no apparent link to the output failure is obvious.

The message on the ACS 800 panel was that

"INT CONFIG 5410"

Two control breakers were tripped.

Now regarding internal temperature, if it exceed, it will trip the VFD. Last week after shutdown, we started the drive and one cooling fan of inverter unitwas not working. Drive was tripped on "Temp Diff V1" (Not exactly remember) within less than 40 sec.

Regarding external temperature, Temperature of the substation normally remains between 20 -25 C. At the time of accident it was 24 C.

Regarding Dirt, three week ago exactly, there was shutdown and we clean all the units of VFD installed in the substation.

Regarding age of VFD's, These VFD are installed at the end of 2007 and from onward they are in operation.

I am also in contact with ABB. As soon as I get some useful information, I will share with all of you.

How did you "clean" the VFD? Compressed air? Not good if you did, there is a lot of moisture in compressed air. Cleaning, especially of the PCBs, should only be done as part of a routine maintenance procedure by factory trained technicians who have the proper equipment.

Ground wires may or may not have been required, it totally depends on the system involved. There are very specific instructions on grounding (earthing) in the ABB ACS 800 manual pertinent to the specific type of power system you are connecting to. Changing that without consulting ABB or their authorized service agent may result in damage.

"Last week after shutdown, we started the drive and one cooling fan of inverter unit was not working. Drive was tripped on "Temp Diff V1" (Not exactly remember) within less than 40 sec." Not good either, things like this don't usually happen without cause, was this on the same VFD that failed?

Both VFD-1 and VFD-2 units were cleaned.The units were not so dusty. We use blower to remove the remaining dust from the unit. If it is due to moisture then this should burn after the start up but the VFD-1 and VFD-2 were running more than 5 days.

After the accidents, after testing cable and motor, we put another inverter unit (We have Spare unit). Now VFD-1 is running normal. No case of Loose connection was found on both side

sounds to me like you've covered most of it, you just have to wait on ABB and a reply.

maybe, or maybe you shorted out some tiny little pull-up resistor on a PC board, which was protecting something else, which was protecting something else, etc. etc. and it took 5 days for the cascading effects to cause a complete system failure.

Regards.

1. Power of Drives & Inverters ?

2. << VFD-1 (unit # 5 ) >> what do you mean? Are the 7 inverters running in parllel as a Redundant system or ... ?

Equipment fail sometime by due-period Mortality.

the 2000 KW motor VFD have six inverter units as U1.1, U1.2, U1.3,U1.4,U1.5,U1.6./ These are the names mention above the inverter units. We have two mills of same capacity. so therefore two same motors and VFD's.

VFD-1 (Unit #5 ) means that inverter unit U1.5 of VFD-1 (Mill-1).

No other unit is damaged among the remaining five. If you have any idea please share with us.

Regards.

Can you give details inverters i.e. Manufacturer,

Is there any Control Module to run the inverters in synchro, freq, phase, voltage etc vise?

Are Inverters using Thyristers or Transistor power modules?

Any information in addition?

Have a fine day.

The VFD manifacturer is ABB

I think Inverter is made of IGBT's (Not sure)

Hi, I think the VFD that had failed was closet to the supply source and thus had the least impedance compared to other drives. Any transient would lead to failure of first drive that offer least Z.