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how many long vfd can lasts?

how many long vfd can lasts?

(OP)
How many long vfd can lasts? I have a vfd eurotherm 620 that was installed in 2001.
This vfd work 8h/day, 5 day/week, 45 week/years. I can't wait 5 week for replacement if it fail.

RE: how many long vfd can lasts?

It might last another ten years, it might fail tomorrow. If it is critical to your business then buy a spare VFD. At 16 years old it has already done very well.

RE: how many long vfd can lasts?

2
If kept in continuous use, the MTBF (Mean Time Between Failure) is typically 200,000 - 600,000 hours, depending on size (200k at the smaller end, 600k at the larger end). Whether or not you accept calculated MTBF values as a legitimate indication of equipment life is a debatable issue, but it's about as close to a scientific evaluation as you can find. Other than that, everything is anecdotal. I am routinely called upon to replace 20+ year old VFDs that are still working fine, but the users have a similar fear of what happens WHEN they fail, because in those cases, the components to REPAIR the drives are no longer made. That actually becomes a more salient issue and as a general rule, I recommend people start considering upgrades at around 10 years, depending on the cost of unexpected down time. So for example if you have built-in redundancy in your system, having to wait 2 weeks to repair a drive may mean you can keep them in service for longer, i.e. 20+ years. But if your system would go completely down if the drive fails and there is no replacement available, taking an extra day to figure out how to set up and interface to a new drive might cost you a LOT more in down time than it will to keep your drives current.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

RE: how many long vfd can lasts?

(OP)
10 years when you run 24h/day or whatever?

RE: how many long vfd can lasts?

Just have a PM routine to power them up once per year for an hour or so.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

RE: how many long vfd can lasts?

Excellent point zlatkodo! One could hunt down an out-of-production new spare and covet it away for that rainy day only to have it pour out smoke from the dead capacitor bank that de-formed over all those years, from not being used.

Keith Cress
kcress - http://www.flaminsystems.com

RE: how many long vfd can lasts?

DE-formed. REforming is the process of forming the AlOx layers again. Energizing the drive once per year for an hour will keep the AlOx layer from deforming.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

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