Feasability of repairing or scrapping blown VFD

atomarc · Oct 3, 2017

I have a brand new, small Hitachi sensorless vector drive I just succeeded in blowing up. It's a 1hp, single phase 'in' unit. New cost is $250. In the past I've had electronic components repaired and typically that cost is 1/2 of new.

Is that still true?

Is this small drive worth fixing?

Who would fix it?

I can hunt around for a answer but thought I'd hit this site first..might save me the hunting around. I didn't pay full attention when screwing with the incoming line and the drive let me know, with a bang. :cryin:

Stuart

Conrad Hoffman · Oct 3, 2017

Maybe you can get them to fix it? This stuff usually doesn't have schematics and the parts can be hard to source, so repair by anybody else is hit and miss and likely not worth the time to pursue. Alas, modern design and assembly methods make things way cheaper to build the first time, than to fix.

JST · Oct 3, 2017

What Conrad said.

That changes if YOU are the repair person, which assumes you have the capability to do diagnosis and repair of such things..

If you have to ask, you are not ready to do that.

3t3d · Oct 3, 2017

One of our former members:

superunknown Now has a popular (but NON serious) channel

BOLTR: Inverter VFDs explained, teardown and test - YouTube

Destroyed VFD teardown and failure analysis - YouTube

Otherwise, youtube and search VFD troubleshooting

Milacron · Oct 3, 2017

atomarc said:
I have a brand new, small Hitachi sensorless vector drive I just succeeded in blowing up. It's a 1hp, single phase 'in' unit. New cost is $250. In the past I've had electronic components repaired and typically that cost is 1/2 of new.

Is that still true?

Is this small drive worth fixing?

Who would fix it?

I can hunt around for a answer but thought I'd hit this site first..might save me the hunting around. I didn't pay full attention when screwing with the incoming line and the drive let me know, with a bang.

Stuart

Over 3,000 posts and you haven't figured out there is a sub forum just for this exact purpose ? Amazing...

rons · Oct 3, 2017

Take it apart and identify whether the line rectifiers are physically damaged. They could be SCR's. Who knows what those little drives have at the front end. It may be fixable.

Looks like nobody is going to move this to the Phase Converter/RPC section.

ewlsey · Oct 3, 2017

From what I have seen, the small and cheap VFDs have one big IGBT module that contains the rectifier, inverter, and flyback circuits all in one. Buying that IGBT module costs more than a whole drive. Thus, you chuck it and move on.

snowman · Oct 3, 2017

Easy to fix. Check rectifier voltage & caps. If those are good, and controller is good, it's the SCR's or IGBT units. Likely parts cost too much to replace those.

Buy a new one.

Tony Quiring · Oct 3, 2017

Contact the manufacturer and ask if it is still supported.

Many such items are exchanged for flat rate cheaper than replacement and often fair.

Manufacturers want to retain customers and keep bad ones off the street as new sales better and exchanging it does both as it gets bad one off street and sells a refurbished or new.

Costs nothing to ask...

We once had a flash light exchange a melted one under warranty as they did not sell the parts separately.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk

JST · Oct 3, 2017

The 1 HP units are basically "throwaway", "cartridge units".

You CAN fix BIG VFDs, where the individual parts bolt to heatsinks. ewlsey is correct, most smallish ones have a "module" that includes all the power semiconductors. Some include driver chips as well.

If you have a lot of those in use, you might swap boards and get some blown ones working with parts from units that failed in other ways. But even then, you tend to run into problems with different PWB versions, or different firmware versions when the hardware is the same.

if you are a commercial shop, buy another.

If you have a hobby shop, and an electronics background, have fun..... But while you will learn a good bit, it may not result in a working unit. Literally the only VFDs I have ever fixed at levels past board swap have been prototypes of ones we made, where I knew everything about them, we needed the unit for some reason, and we had lots of parts.

It is not worth the work or the cost with modern low cost VFDs.

MattiJ · Oct 4, 2017

JST said:
The 1 HP units are basically "throwaway", "cartridge units".

You CAN fix BIG VFDs, where the individual parts bolt to heatsinks. ewlsey is correct, most smallish ones have a "module" that includes all the power semiconductors. Some include driver chips as well.

WAG for what is worth fixing might be somewhere above 10-20 kW range.

Lakeside53 · Oct 4, 2017

I have a $138 TEC 1hp that is "dead". Took it apart. frigg.. there a lot of stuff in the package for the money. I fix pretty much very thing, but this one will be difficult due to the assembly of several modular PCB that end up soldered together. Not really designed to be repaired, even by the manf.

CarbideBob · Oct 4, 2017

atomarc said:
....
Is this small drive worth fixing?...

I'm going to go with some others.... NO,..... and yes I have the learned skills and equipment to do it and still would not.

adama · Oct 4, 2017

All the smal ones that were dead i have ever pulled apart had several modules that were not readily available, much short of dead capacitors and IMHO your wasting your time. The modules are proprietary and normally soldered to the bottom of a stack of soldered together boards, kinda as non easily fixable but easy to make as they could be.

That said by all means pull it apart, give it a once over for anything obvious + a good clean and you can get lucky, me im not normally lucky with VFD's. Now capacitors that have failed on PC mother boards, hell yes, have done repairs north of 30 capacitors and had dead PC's working once more! But had very little succes do to parts availability and other issues with a whole bunch of different drives and switch mode power supplies. often when one bit fails in them it kinda cascades through em taking out multiple things. Replaceing one dead bit oftern gets killed by the others so you end up tail chasing or replacing so much it becomes non cost effective!

CountryBoy19 · Oct 4, 2017

Tony Quiring said:
Contact the manufacturer and ask if it is still supported.

Many such items are exchanged for flat rate cheaper than replacement and often fair.

Manufacturers want to retain customers and keep bad ones off the street as new sales better and exchanging it does both as it gets bad one off street and sells a refurbished or new.

Costs nothing to ask...

We once had a flash light exchange a melted one under warranty as they did not sell the parts separately.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk

This is a valid suggestion. I once sent a Swiss watch back to Switzerland for repair. New cost of the watch is $230, repair of this specific failed/broken part is $53. In the end I discovered that "repair" in this instance was simply replacement of the watch at their cost. I received a brand new watch and asked the CS rep if that was standard or mine just wasn't repairable. "Oh no, all watches with that particular failure just get replaced at our cost on the watch"

JST · Oct 4, 2017

adama said:
...... often when one bit fails in them it kinda cascades through em taking out multiple things. Replaceing one dead bit oftern gets killed by the others so you end up tail chasing or replacing so much it becomes non cost effective!

Absolutely true.

If you really MUST replace dead IGBTS, you always replace the driver chips, and all the "silicon" around them, diodes, etc, plus everything between the driver and the IGBT, resistors, diodes, whatever. It is not worth trying to avoid replacing some 3 cent part that is likely bad even if it looks OK.

Also, failures often damage the PWB, burned components char the board, undermine and loosen solder pads, etc, making even a functional repair a bit chancy.

At that point, your own time spent plus parts, plus the lost time NOT doing something that pays, probably exceeds the cost of the unit, without resulting in a new, known good unit. Not a sound business proposition.

Matt Matt · Oct 8, 2017

Typically micro drives are not really worth repairing. I Purchased over 50 drives in the past year and 1 Micro drive for a 1/2 hp drill press. The larger drives I purchase come in three components. Capacitor board, high-voltage IGBT board, low-voltage/programming control board and CAT5 input display board. In one 5 hp, the IGBT folded and I applied for warranty. They ship me out a full new board with no charge but, I had to pay for shipping($25). I did a re-and-re, took me less than 15 minutes at the bench.

It took me 6 times longer to re-and-re A iPad Air battery two night‘s ago.

Not all manufactures make them serviceable.

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Feasability of repairing or scrapping blown VFD

atomarc

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rons

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