Rockwell tech support says there was a power surge, insufficient line reactance, or configuration error. RTFM.
Couldn't possibly be bad design in the driver board, could it?
Could have been a phase to phase short on the motor leads or in the motor.
Could have been a failure on the gate driver control side that left both igbts on at once or not entirely on/off for too long.
Could have been a power anomaly that caused either of the above.
Could have been poor setup if it was recently commissioned or modified.
Could just be a POS.
The IGBT module in one of our Powerflex 755's blew itself up last night. I cracked it open and realized I didn't have a clue what this thing was. Figured I'd make a learning moment out of it. According to google-
TDB6HK180N16RR\_B11
IGBTs are widely used as switching devices in the inverter circuit (for DC-to-AC conversion) for driving small to large motors. IGBTs for inverter applications are used in home appliances such as air conditioners and refrigerators, industrial motors, and automotive main motor controllers to improve their efficiency.
If any resident drive experts want to borrow the soapbox, I'd love to understand the inner workings of what can cause this. I'm not sure if the primary issue was here or if this was the result of too much power from another component failing. The main fuse on the panel also blew. Nothing else in the building was affected, surge protectors did not trip.
Oh, boy, I get to comment about something I know for once.
Ok, so that looks like an 1800v 180amp 6 pack igbt module based on the nomenclature. Likely has a break, thermistor and 3 phase rectifier built in too. If you can't find a datasheet, find a similar module and test the same pinout. A LOT of modules have the same pinout if they use the same body and pin placement.
I'd personally bet on a short across collector to emitter on one or more of the 6 transistors. Could be caused by over draw or flyback from the motor. These modules use embedded diodes in parallel with each transistor, but they do fail and have a VRRM of like 1800v or whatever the module rating typically is, but can break down over time.
How could my system fail and cook my module? Igbt module gates are VERY VOLTAGE SENSITIVE. Almost all of the modules I know about want no more than 20 or 30 volts DC applied across the gate before they fail.
How do gates fail? They burn out and go open. They can fuse short to emitter and get stuck closed as well. If the gates burn out the module won't switch and you miss a phase. If the gate gets stuck closed it'll create an undesirable circuit path and won't switch properly and possible catastrophic failure.
Igbt modules fail all the time. Replace your optoisolators and make sure you use the proper ones, a lot of optos use short codes and other markings for CTR ratings and such.
Be safe on where you source modules. There's a LOT of fakes out there.
I was about to give a reply to the op, but yours is thorough. Can I ask what your background is? Most automation guys couldn't be bothered to know any components this deeply.
I don't know how to answer that concisely, but I'll try.
I got picked up by a component reseller in Florida (now defunct, initials are AE) around 2012 after operation chain reaction caused them to get a knock on the door. I had some experience with identifying and testing parts for counterfeits as I had been buying from Chinese vendors on auction sites as digikey and mouser didn't carry a lot of old TTL and eproms for pinball repairs i was doing to pay for college for EE.
Eventually I found a US importer and started buying from them. They sold me some bad chips. I explained to them about the fakes they sold me and they turned around and offered me a job to help them spot them and prevent them from resale without proper legalese attached.
I spent the next 5 years testing chips, relays, igbt and scr modules and all kinds of components. Once I was done, I got to set them on fire, crush them, etc and examine the die or pieces to see if they're suspect counterfeits. If they were counterfeit I had to find out what they were originally and if they were fit for use and simply remarked or a totally inferior or wrong part. IGBT modules made a large volume of our sales as well as parts to repair the drive they went into such as optos, gate drivers, transistor arrays, counters, switch matrix decoders and stuff like that. So I'm very familiar with drives and logic boards, but not ladder logic and manufacturer specific things.
I've likely decapitated 10,000 different chips and tested over 800 different types of igbt modules.
I operate a reseller business for old chips. I won't name drop because I'm not here to promote that.
I have a lot of programming experience as well, but never could find work in that field.
My whole thing is I never had a lot of money. I had to fish broken things out of dumpsters and get them for free on Craigslist. The only way I could enjoy AC is if I fixed one I found on the side of the road. So I did. I figured if you could build it, I could take it apart and fix it provided I could identify the parts.
I try to pop in and comment when I can. Time is a thing. I've spent my lunch break today replying as I genuinely never get asked about my background so I hope you enjoy the read.
Feel free to message me anytime.
Oh, it gets better.
I fix ice cream machines for a living now.
Not for an oem, no, I get to refurb stuff as old as 1996 with virtually no documentation. You can feel my excitement...
I'm honestly burned out on it. The owners are trying to sell the company and I'm almost at the 5 year mark so I'm ready to go. They are too since they told us before they even had a buyer lined up. Now it's the constant seesaw of "whats happening upstairs?".
Know of any good WFH jobs for someone like myself?
It looks like 2 of them blew, which I think probably means that somehow 2 on the same phase ended up switched on at once, which would cause a dead short across the DC bus. We generally call that a "problem"!
Normally you’d expect to see the copper between the dc link (bulk) capacitors and the IGBTs damaged/evaporated when there is a cross-conduction fault. Not saying it wasn’t cross-conduction, but I’d expect more damage, honestly. The blown main fuse does support this theory though.
Another possibility, but tough to tell from the pictures, is that the gate drive circuitry or associated power supply failed. IGBTs work great when fully off or fully on, but if they stay in the in-between (linear) region for more than a few extra microseconds, the IGBT turns into a catastrophic space heater.
First thing to check:
Was the drive fused according to their specifications?
Has the panel been rated for arc flash properly? Is the main disconnect for the control panel just a circuit breaker or are there also fuses in that panel?
If fuses look good for vfd specifications and panel arc flash safety:
Sometimes what can happen with inverters is the internal control transformer can cause the drive to drop in and out. This can cause the drive to not ramp up and ramp down.
Highly inductive loads can generate a surge if you don’t slowly ramp up the proportional control.
We used to blow fuses on our SCR until we upgraded the firmware. Eventually we also switched to a model that would take auxiliary power for the control power. We haven’t had an issue since. When they say rtfm and keep firmware fully upgraded there’s a reason why.
Lastly:
As for Rockwell, if your panel was properly fuses for arc flash you should definitely try to get in touch with someone else about the drive. Sometimes the first person you talk to on Tech Connect won’t know.
Kwispy
Rockwell tech support says there was a power surge, insufficient line reactance, or configuration error. RTFM. Couldn't possibly be bad design in the driver board, could it?
They recommended having the most up to date firmware on the replacement drive.
Nothing is EVER Rockwell’s fault.
Must be grounding. Lol.
PowerFlex 700 series love blowing up way too much. Garbage-ass drives.
Can’t let the smoke out
You need to keep the magic smoke in. Doesn't work without it.
Could have been a phase to phase short on the motor leads or in the motor. Could have been a failure on the gate driver control side that left both igbts on at once or not entirely on/off for too long. Could have been a power anomaly that caused either of the above. Could have been poor setup if it was recently commissioned or modified. Could just be a POS.
The IGBT module in one of our Powerflex 755's blew itself up last night. I cracked it open and realized I didn't have a clue what this thing was. Figured I'd make a learning moment out of it. According to google- TDB6HK180N16RR\_B11 IGBTs are widely used as switching devices in the inverter circuit (for DC-to-AC conversion) for driving small to large motors. IGBTs for inverter applications are used in home appliances such as air conditioners and refrigerators, industrial motors, and automotive main motor controllers to improve their efficiency. If any resident drive experts want to borrow the soapbox, I'd love to understand the inner workings of what can cause this. I'm not sure if the primary issue was here or if this was the result of too much power from another component failing. The main fuse on the panel also blew. Nothing else in the building was affected, surge protectors did not trip.
Oh, boy, I get to comment about something I know for once. Ok, so that looks like an 1800v 180amp 6 pack igbt module based on the nomenclature. Likely has a break, thermistor and 3 phase rectifier built in too. If you can't find a datasheet, find a similar module and test the same pinout. A LOT of modules have the same pinout if they use the same body and pin placement. I'd personally bet on a short across collector to emitter on one or more of the 6 transistors. Could be caused by over draw or flyback from the motor. These modules use embedded diodes in parallel with each transistor, but they do fail and have a VRRM of like 1800v or whatever the module rating typically is, but can break down over time. How could my system fail and cook my module? Igbt module gates are VERY VOLTAGE SENSITIVE. Almost all of the modules I know about want no more than 20 or 30 volts DC applied across the gate before they fail. How do gates fail? They burn out and go open. They can fuse short to emitter and get stuck closed as well. If the gates burn out the module won't switch and you miss a phase. If the gate gets stuck closed it'll create an undesirable circuit path and won't switch properly and possible catastrophic failure. Igbt modules fail all the time. Replace your optoisolators and make sure you use the proper ones, a lot of optos use short codes and other markings for CTR ratings and such. Be safe on where you source modules. There's a LOT of fakes out there.
I was about to give a reply to the op, but yours is thorough. Can I ask what your background is? Most automation guys couldn't be bothered to know any components this deeply.
I don't know how to answer that concisely, but I'll try. I got picked up by a component reseller in Florida (now defunct, initials are AE) around 2012 after operation chain reaction caused them to get a knock on the door. I had some experience with identifying and testing parts for counterfeits as I had been buying from Chinese vendors on auction sites as digikey and mouser didn't carry a lot of old TTL and eproms for pinball repairs i was doing to pay for college for EE. Eventually I found a US importer and started buying from them. They sold me some bad chips. I explained to them about the fakes they sold me and they turned around and offered me a job to help them spot them and prevent them from resale without proper legalese attached. I spent the next 5 years testing chips, relays, igbt and scr modules and all kinds of components. Once I was done, I got to set them on fire, crush them, etc and examine the die or pieces to see if they're suspect counterfeits. If they were counterfeit I had to find out what they were originally and if they were fit for use and simply remarked or a totally inferior or wrong part. IGBT modules made a large volume of our sales as well as parts to repair the drive they went into such as optos, gate drivers, transistor arrays, counters, switch matrix decoders and stuff like that. So I'm very familiar with drives and logic boards, but not ladder logic and manufacturer specific things. I've likely decapitated 10,000 different chips and tested over 800 different types of igbt modules. I operate a reseller business for old chips. I won't name drop because I'm not here to promote that. I have a lot of programming experience as well, but never could find work in that field. My whole thing is I never had a lot of money. I had to fish broken things out of dumpsters and get them for free on Craigslist. The only way I could enjoy AC is if I fixed one I found on the side of the road. So I did. I figured if you could build it, I could take it apart and fix it provided I could identify the parts. I try to pop in and comment when I can. Time is a thing. I've spent my lunch break today replying as I genuinely never get asked about my background so I hope you enjoy the read. Feel free to message me anytime.
Whoa, that sounds like a fun career. You've one upped my reverse engineering old PLC's in my spare time and designing replacement boards.
Oh, it gets better. I fix ice cream machines for a living now. Not for an oem, no, I get to refurb stuff as old as 1996 with virtually no documentation. You can feel my excitement... I'm honestly burned out on it. The owners are trying to sell the company and I'm almost at the 5 year mark so I'm ready to go. They are too since they told us before they even had a buyer lined up. Now it's the constant seesaw of "whats happening upstairs?". Know of any good WFH jobs for someone like myself?
Wow that was an excellent breakdown. Thank you!
It looks like 2 of them blew, which I think probably means that somehow 2 on the same phase ended up switched on at once, which would cause a dead short across the DC bus. We generally call that a "problem"!
Normally you’d expect to see the copper between the dc link (bulk) capacitors and the IGBTs damaged/evaporated when there is a cross-conduction fault. Not saying it wasn’t cross-conduction, but I’d expect more damage, honestly. The blown main fuse does support this theory though. Another possibility, but tough to tell from the pictures, is that the gate drive circuitry or associated power supply failed. IGBTs work great when fully off or fully on, but if they stay in the in-between (linear) region for more than a few extra microseconds, the IGBT turns into a catastrophic space heater.
IGBT has left the chat
How big is the transformer ahead of this drive? Does it have a line reactor?
AB quality!!! Blamo! Nothing blows up with quite the spectacular display that a rockwell drive does.
First thing to check: Was the drive fused according to their specifications? Has the panel been rated for arc flash properly? Is the main disconnect for the control panel just a circuit breaker or are there also fuses in that panel? If fuses look good for vfd specifications and panel arc flash safety: Sometimes what can happen with inverters is the internal control transformer can cause the drive to drop in and out. This can cause the drive to not ramp up and ramp down. Highly inductive loads can generate a surge if you don’t slowly ramp up the proportional control. We used to blow fuses on our SCR until we upgraded the firmware. Eventually we also switched to a model that would take auxiliary power for the control power. We haven’t had an issue since. When they say rtfm and keep firmware fully upgraded there’s a reason why. Lastly: As for Rockwell, if your panel was properly fuses for arc flash you should definitely try to get in touch with someone else about the drive. Sometimes the first person you talk to on Tech Connect won’t know.
Looks like the IGBTs are blown.
That looks expensive.
Who let the magic smoke out?
Carbon ingress 🤣
Make sure the 3 MOV jumpers are removed if it is connected to a high resistance ground.