Igbt

[kaareem]

HI everyone
I have removed motor connections from VFD and tested its showing now igbt short circuit in fault history and I done test procedure I found 6 igbt are open, what it's means and why it's happened
Firstly I would like to inform that with morot connection it's alarm was igbt desaturation and now when I started without motor it's alarm changed I want to know why it's happened, is this possible that without motor igbt will be short circuited ?????
Please let me know
Thanks everyone for replying me

 

[kaareem]

HI everyone
I have removed motor connections from VFD and tested its showing now igbt short circuit in fault history and I done test procedure I found 6 igbt are open, what it's means and why it's happened
Firstly I would like to inform that with morot connection it's alarm was igbt desaturation and now when I started without motor it's alarm changed I want to know why it's happened, is this possible that without motor igbt will be short circuited ?????





HI everyone please help me out
Please let me know
Thanks everyone for replying me

It would be appreciated

 

[okoye]

Hello friend...
You are not clear in your communication.
Mind your typos and rephrase your expression in simple and correct English...so you can get the help you need.

 

[kaareem]

Hello friend...
You are not clear in your communication.
Mind your typos and rephrase your expression in simple and correct English...so you can get the help you need.

HI sir
I have one altiver 61 600hp controller, during runtime it is stopped and in fault history it's shows IGBT desaturation, I make it reset several times, but fault occurred again , so I removed motor connections from VFD and tested VFD, fault happened again but this time fault is IGBT short circuit and in test procedure it's showing IGBT open
My question is did IGBT get short circuited due to run VFD without motor???
Is this possible???
Why IGBT desaturation fault happened???

 

[okoye]

My question is did IGBT get short circuited due to run VFD without motor???
Is this possible???
Why IGBT desaturation fault happened???

Your 3 questions are clearer now...

1). Yes... provided that the IGBT was already short while the VFD was driving its motor.
A shorted IGBT remains a shorted IGBT whether or not motor is connected to the VFD.
According to you, after you did a Diagnostic test without the motor connected to the ATV-61, it reported same that IGBT was shorted.

2). It is possible.
3). This fault arise if the following happen:
(i). If the cable between the motor is shorted to to Earth. If so, disconnect the cable from the VFD end and the Motor end and carry out a Megger Test on the cable for Leakage.
(ii). If the electric Motor windings is shorted to Earth. If so, also carry our a Megger Test on the motor too after disconnecting motor and VFD.
(iii). Age of the VFD may also cause this problem.

Before conclusion, If motor and cable are okay, isolate the VFD and repeat the Diagnostic Tests, both for the Thyristors and Transistors. If IGBT desaturated occurred again, look through the ATV-61 manual to see if the IGBT is among the list of customer replaceable components on this 600 h.p Drive...if it is... you can reach the Customer Support Center in your locality and place an order.
I hope these helps...
Pcontrols (Okoye).

 

[kaareem]

My question is did IGBT get short circuited due to run VFD without motor???
Is this possible???
Why IGBT desaturation fault happened???

Your 3 questions are clearer now...

1). Yes... provided that the IGBT was already short while the VFD was driving its motor.
A shorted IGBT remains a shorted IGBT whether or not motor is connected to the VFD.
According to you, after you did a Diagnostic test without the motor connected to the ATV-61, it reported same that IGBT was shorted.

2). It is possible.
3). This fault arise if the following happen:
(i). If the cable between the motor is shorted to to Earth. If so, disconnect the cable from the VFD end and the Motor end and carry out a Megger Test on the cable for Leakage.
(ii). If the electric Motor windings is shorted to Earth. If so, also carry our a Megger Test on the motor too after disconnecting motor and VFD.
(iii). Age of the VFD may also cause this problem.

Before conclusion, If motor and cable are okay, isolate the VFD and repeat the Diagnostic Tests, both for the Thyristors and Transistors. If IGBT desaturated occurred again, look through the ATV-61 manual to see if the IGBT is among the list of customer replaceable components on this 600 h.p Drive...if it is... you can reach the Customer Support Center in your locality and place an order.
I hope these helps...
Pcontrols (Okoye).

Thank you for your concern and sharing your experience with me, thanks A lot
1.I would like to know what's the difference between IGBT desaturation and IGBT short circuit (open)
2.bcoz when motor connected its shows desaturation without motor it's showing short circuited (open)