480 volt VFD

Are 480 volt FVDs Alan Bradley desirable at all or even feasible? 480 input but will output 240. I can pick up a few of them but don't want to have to sit on them for years.

Any drive can put out a voltage that is lower than you put in, it's just programming as far as the drive is concerned. But that's a really BAD idea for the motor. In a 480V drive, the DC bus voltage is around 635VDC, so the pulses going to the motor are at that level too. On a 480V motor winding, that's OK, but on a 240V motor winding, it is REALLY stressful on the winding insulation and will cause premature death.

As to Allen Bradley drives being "desirable", it depends on the drive. We (I work for A-B) recently obsoleted an old product line that was, in it's day, very popular, the 1336 products. So people have not been able to buy new drives for 10+ years now, but the change is, they can no longer buy PARTS for those old drives. As a result, we offered large users a rebate program for them to upgrade to new series drives, provided they destroy the old 1336s when they removed them. Lots of people cheated and are trying to sell off those old drives, but for all intents and purposes, they are almost worthless to anyone who is serious about reliability. They are all over 10 years old and many have been sitting on shelves un-powered, so the caps are dried out and need reforming, or they have already been compromised by people who didn't know that. Then when something goes bad, there is no reasonable repair path for them, all you can do is find cannibalized parts and hope they are good.

So beware. If you want one to play around with, and they are dirt cheap or free, go for it. If you want to use one on something that you make money with, re-think it.

These are Powerflex 70 models, My buddy got several and his had a 2010 manufacture date on it. I looked on Ebay and the asking prices were all over the board from a couple at $70 each to $1200 each but not one with bids.

I don't know anything about the Powerflex 70s, but I've got a bunch of 1305 and 1336S drives, and I haven't had one iota of trouble with any of 'em.... kinda makes me sad that J's company is having them destroyed, because I'll wave the A-B flag simply because they do the job I want 'em to do, without issue... the only complaints I've ever had, are the flimsy packaging and the seemingly endlessly complex documentation... the latter being somewhat forgivable considering the noted products' massive array of options and programming flexibilities...

I guess, the way I look at it... is that I got my A-Bs dirt-danged-cheap, and I'm not using them for anything other than my personal non-commerical, non-industrial workshop... I took the time to breach the learning-curve and make these buggers rock-and-roll... including the risks of frying 'em... and found success and happiness such that if someone asks, I'd recommend them based on my personal experience. I certainly couldn't afford them at NEW price, not for what I'm doing here- this is not a business economic model, it's my workshop.

Now, my first exposure TO these products, was long ago, in previous occupation, and it was back when the 1336S was a relatively NEW product, and my company (then) used LOTS of these drives. The folks I worked with then, were good people, but bein's that I was part of engineering DOCUMENTATION, they weren't inclined to give me the time-of-day, but I didn't argue- the guys sweating out details in the R&D shop were charged with that duty, not I... but our products worked well, and didn't suffer any issues as a result of the A-B product. Betwixt that experience, and my (much later) experience using them in my own equipment, I'll grant them a kudos for what they're now dismissing as obsolete. If my company were to look to me for my recommendation for drives for oh... the next 370 motion control systems that the guys down the hall are fitting at 60 sites, I'd recommend AB based on my 1305 and 1336 experience.

I think it sadly inconsiderate and foolish to incentivize the destruction of such things, when they'd be gladly accepted by a class of customer who would, in their non-work life, be otherwise unable to justify buying a NEW product, but instead, turn to their competetors for a MUCH CHEAPER product, because in doing so, they're in effect, supporting the advancement of an otherwise inferior production... like Huangyang... and of course, throwing away the opportunity to get first-hand support from folks who would otherwise bolster choice within their professional lives.

It's about as intelligent as oh... "Cash for Clunkers"...

what jraef says is true, but not the whole story.

You may not need to run them on 480V. Many drives will work on a range of voltage that can include at least the next lower international voltage range below. What we in the US call a 480V drive, may actually work on anything from 380 to 575V, and possibly lower. Read the spec and see.

If you do run them at 480, then yes, you should use a motor that is rated 480V or 240/480. The insulation system in lower rated motors may not stand up to the higher voltage plus transients.

As to the obsolescence.... A-B is definitely NOT "protecting the user"..... they are, purely and simply, saving money for themselves. The drives won't dry out from non-use, they dry out from USE, heating etc. and other parts than electrolytics are of course not affected. But there is some need to "freshen up" boards after some time etc, and they don't want to. They may feel they don't want to offer a guarantee on the parts.

There is a little sense to it in that there may be degradation if parts are kept long enough. I don't think 10 years is enough, we re-commissioned a nearly 20 year old drive with zero problems, and I wouldn't expect them. But the drive is not one that I'd want to install new... features are just not there.

In fact, A-B just doesn't want to keep selling parts that cost money to stock and maintain as inventory, and reckon that they will spend less by dumping them in the landfill and taking the hit once. Why effectively subsidize operations that act to prevent new sales of your product?

So does anybody want any of these VFDs at lets say $75.00 shipped in the U.S.?

What is the model number on the side of the drives?

Two comments on using a 480V drive on a 240V motor . . .

If you can get a Load Reactor - that will help knock down the peak voltages the motor windings see and will extend the life of a marginal motor.

If you set the drive up using motor nameplate data . . . you are missing out on some performance. Set the motor up at 2x its synch speed minus the slip speed at 120Hz and rated current and you will find that you will get a lot more speed range out of the motor (as long as the bearings are in good shape).

Have fun!

thermite said:

Beg to differ. They ARE 'protecting the user'. Forget the hobbyist working not at 'zero per hour' but actually subsidizing his effective (negative) hourly rate. Look at what the myriad of independent repair organizations charge. Higher than NEW prices in many cases. They HAVE to do. Goods made in high volume on automated PCB stuffing lines have near-zero labour content. Sitting down at a bench to analyze a board, find and then repair a fault, amortize test equipment, staff training investment, stocking of seldom-used spares - is WAY more costly.


Bill

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Oh, my.....

Not what I had in mind.

I'm thinking about basic "ugh, board bad, order another" level repairs..... AB would have had NOS boards, and all that is really required is to ship one out in response to an order.

But the bean counters can tell you just how much it costs to have that board in stock.... and it will always look bad on the bottom line...That's what bean counters do.

I would call 15 years far enough.... 5 is not acceptable, and 10 is pushing it for industrial stuff, which often lasts far longer.

Machine tools are "unit replaceable", so stand-alone CNC is forklifted out to the scrapper on a regular basis. But drives integrated into larger things are less so. By forcing the replacement of drives, ABB also begins to force the replacement, or retirement unreplaced, of the whole thing, since the same sort of bean counter is operating at the drive user's place..... reprogramming and adapting-in new drives is uneconomical, and the drive may use a form of comm that isn't available, etc, etc.

It's unfriendly not to support drives which customers have an investment in that goes well beyond the drive's cost alone.

And, ABB IS essentially lowering their costs at the expense of the users.

It's a trend now.... for consumer goods, once the warranty is over, you are EXPECTED to landfill the unit.... quite a number of companies refuse to allow non-warranty repairs.... enforced by a refusal to supply parts without a warranty claim to account for them.

For both cases the root cause is that the vendor does not make the unit, they buy it in. As a result, they don't stock anything but complete units, and cannot supply parts except for those they have pre-ordered with the original units. No re-order would come up to the minimums.

"Stale" shelf stock is cheaper to landfill than to keep. I'd bet ABB will soon be stocking repair parts no longer than 2-3 years after the last production..... if that long, and if they even do that at all.

Remember, nobody says they have to keep MAKING the old stuff, nor that they can't develop new and better stuff (or new and better OEM relabel sources). That's expected.

The problem arises when your hundred meter long line needs a replacement drive of that particular type, you used the last spare, and you find that neither a replacement nor parts to repair what you have are available..... and new drives don't speak the old control language. Let's see just how long the downtime will be......

thermite said:

If it is a REAL issue for your two-miles of production line? Stock more spares.

Or build yer own gear and stock spares AND components AND keep Engineers and technicians on payroll for that.

That's the sort of approach it takes to keep B-52 bombers airworthy and still capable of bringing extreme pee.
I'm sure it ain't cheap.

Bill

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it's a pain none-the-less, when your bottle line or whatever that has been running for 15 years is essentially obsoleted by the drive type disappearing.... "too expensive to keep running, we need to get back to our core business"....

bean counters fight tooth and nail against spares..... and then against repairs, and finally against modifications to keep stuff running. Back to the 60's... up against the wall, m-------s.........

When you DO run out of parts, that's the end.... let the specialty side players deal with the detail repairs. That level of component repair often involves NO special spares, just older parts, for which there are often newer subs. But no problem for the mfgr.

It's throwing out a pile of good spares to help the bottom line that bites. Genrad threw out a big warehouse full of spares one day years ago... "we don't support those instruments anymore".... and they didn't.

Here's some pics and data on the VFDs I have 4 of them

I picked up 2 of these Eco Drives

Here's some data on the Ultra 3000 I only got 1 of these

motion guru said:

Two comments on using a 480V drive on a 240V motor . . .

If you can get a Load Reactor - that will help knock down the peak voltages the motor windings see and will extend the life of a marginal motor.

If you set the drive up using motor nameplate data . . . you are missing out on some performance. Set the motor up at 2x its synch speed minus the slip speed at 120Hz and rated current and you will find that you will get a lot more speed range out of the motor (as long as the bearings are in good shape).

Have fun!

Click to expand...

I've noticed this idea on several threads on this board, but any one post I've yet come across doesn't have enough detail for me to really understand what's going on here, and why it works... Is there someplace I could find a detailed description of this technique, including necessary conditions and pros/cons?