# Allen Bradley powerflex 4 22a-d4p0n104



## John Valdes (May 17, 2007)

I bet the front end of that drive is fried.
Have you checked the input section? 
Had any bad weather lately with lightning?


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## micromind (Aug 11, 2007)

What type of service does the building have?

If it's a 120/240 3Ø 4W wire ∆, you'll need to disable the MOVs in the input section or they'll short out.


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## JRaef (Mar 23, 2009)

That part number is for a 480V 2HP drive, but what Micromind said is still valid. If the drive is fed from a 480V ungrounded Delta or a Resistance Gounded Wye system, there are MOV ground reference jumpers in the VFDs that must be removed. If not, the first time there is a GF anywhere else on the system, the little MOVs in that drive attempt to become the Wye point of your grid for about 16 milliseconds, then vaporize in the process. When they go, they coat everything else with conductive material and everything else flashes over. it's all over in an instant, and that is an unrecoverable fault.

Scenario 2, and one that is unfortunately happening more now, is that some crackhead copper thief has cut out an exposed GEC at your service transformer, so you are now running on an ungrounded Wye, which only shows up in a case like this.

And... there is nothing repairable on PowerFlex 4s... it's all surface mount technology, as are all small drives like that now.


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## Jay Freeman (Aug 2, 2017)

John Valdes - I haven't found a bad component yet. For one of them, I believe the display lights up ok but when run is pushed... boom. The other drive goes boom on power up. No storms that I am aware of.

Micromind - Input power is 480v 3 Ø. Do you just cut the legs on the MOV's?

JRaef - The MOV's appear to be intact and the inside of the drive looks like new. After installing a new drive, the door works fine. I found a site that advertises repair of these drives for a flat rate. What if the surface mount components are not bad? What if the bad part is the section mounted to the heat sink? 

If I had a schematic, I could go a bit further with trying to figure out what blew up. Whatever it is... there are no visual clues.


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## Jay Freeman (Aug 2, 2017)

Where is the "Edit" button so you can fix you message after it gets posted?


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## JRaef (Mar 23, 2009)

Jay Freeman said:


> John Valdes - I haven't found a bad component yet. For one of them, I believe the display lights up ok but when run is pushed... boom. The other drive goes boom on power up. No storms that I am aware of.
> 
> Micromind - Input power is 480v 3 Ø. Do you just cut the legs on the MOV's?
> 
> ...


The parts that are attaching to the heat sinks are attached to the PC boards via surface mount on the other side, at least on the one in front of me. Some companies advertise that they can repair anything, then send it back to you no-charge saying it was repairable, but it cost you the freight both ways... At A-B, they will basically charge you $150 to "repair" it, but in reality you are getting back a different unit that was taken back for a firmware glitch, updated with new firmware, then put in the "replacement pool".

if your unit doesn't "pop" until you hit the Run command, that points to an output transistor. In small VFDs like this, all of the output transistors, input diodes and the firing circuits are in a monolithic epoxy filled block called an "IPM" (Intelligent Power Module), which is the blocky thing you see attached to the heat sink. If one component inside blows, the whole thing is toast. here's what one looks like inside with the epoxy removed.








Then not only is the IPM surface mounted to the PC board, a replacement unit bought one-off will cost more than an entire new VFD. Then there is no guarantee that what caused a transistor to fail was IN the actual IPM and not in the other PC board, so if you did manage to replace it, you fry the new IPM...

All small VFDs are build this way now by the way.


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## John Valdes (May 17, 2007)

I would install line reactors and replace both of them.
Drives this size are throw aways.


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## Jay Freeman (Aug 2, 2017)

JRaef - $150 for a repair/replacement isn't bad. What all is involved with sending AB the drives? Thanks for the info. I'd like to get some spares asap.

John Valdes - They were replaced and the doors are working fine again. There is no place to install reactors plus these drives worked fine "as is" for about 10 years.


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## JRaef (Mar 23, 2009)

Just contact your local authorized AB distributor and tell them you want to send in these drives for repair. Make sure they know you are not expecting a warranty replacement, otherwise you lose a couple of weeks in back and forth pointless emails...


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## Sblk55 (Sep 8, 2017)

We have sent a few out to 3rd party repair. about 6 week turnaround. Have a few installed but only for about 2 weeks, so donot know yet. Price about half of a new one. Was told by AB that at about 10 years the DC buss starts getting week. upgrade firmware at same time. Must watch if using multiples in same machine must be same firmware or will not play together well.

good luck


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## Jay Freeman (Aug 2, 2017)

SBLK55,

Yeah, that explanation sounds about. I had 3 drives go up within weeks of each other... all about the same age. Luckily, we only have 4 of these drives total. That leaves one more to crap out any time now. tic toc tic toc


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## Jay Freeman (Aug 2, 2017)

I meant to say "sounds about right"

This forum needs an edit function...


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## JRaef (Mar 23, 2009)

You can edit a post for about 15 minutes after you post it.


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