Non squeal VFD

Packing line upgrade time...
My bin dump water pump is the largest noise maker in the system. I quickly tried a VFD a couple years ago and it SQUEALED far worse than
the excess motor noise. Just as pleasant as listening to chalk squeal on a blackboard.
Anyway, this time I want to buy a 1/2 hp VFD that doesn't have carrier wave noise. Suggestions? BTW, the unit will be located 75' of wire from the motor. Is a reactor needed in this case?
Karl
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What is the actual source of the noise?
I run a 1/2HP VFD and 5HP VFD in the high power side cabinet on my Hurco, and both are virtually silent. The servo dithering is louder than either one.
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wrote:

Like Gunner said, and you implied, I just had bad luck last time. i also have many VFDs with no noise. But, this is a much quiter level, trying to get less noise than a dot matrix printer.
The problem was two years ago, maybe more. Folks on this group said it was carrier wave and I seem to remember reactor being suggested. But my memory sux and maybe who ever said it was full of beans.
Anyway, should i pop for a reactor? I've bought from automation direct before with good results.
Karl
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If the squeal is coming from the motor itself, the reactor(s) will help smooth the 'simulated sine wave' coming out of the inverter drive.
Good VFD's divide the stepped waveform up into small enough slices so that the noise is of a high enough frequency not to be heard by us old men, and not annoying to anything but cats and bats and teenagers (a good thing).
I've used the Automation Direct VFDs and also Motortronics, with which I have had very good experience and reliability. No noise from either brand.
Lloyd
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On Mon, 19 Aug 2013 18:02:08 -0500, "Lloyd E. Sponenburgh"

You hit the nail on the head about teenagers. i though it was quieter, they threatened to mutiny.
Karl
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On Mon, 19 Aug 2013 18:02:08 -0500, "Lloyd E. Sponenburgh"

The later Rockwells I've used had a menu item to change the carrier frequency if noise was evident. Our vendor recommended reactors if 200' or more. Something to do with harmonics on the feed line. Mine were usually about 10' or less. Mitsubishis I have now are quiet except I can hear the cooling fans.
Good luck.
Pete Keillor
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    I think that the squeal is likely from loose laminations in the stator of the motor -- and likely just right to be resonant at the default frequency of the VFD -- so a change in frequency would likely make a big difference. (An alternative is to force a varnish into the laminations -- but be sure to pick one which will not attack the varnish/enamel on the wires wound on there.) Maybe a very thin epoxy would work.
    A reactor might reduce the high frequency part getting to the motor windings -- but is otherwise unlikely to be necessary.
    A replacement motor will likely not show the same problem -- even if the same brand. But it might be the most expensive approach.
    Good Luck,         DoN.
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My impression has always been that the PWM frequency was simply too low on first-generation inverters; and that while anything built within the past couple decades might well still create some annoyong electrical noise, acoustic emmissions will be at a frequency substantionally above the human hearing threshold
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I don' know what the total range of human hearing is, but when I was younger I could hear or be aware of frequencies upto about 20kz. Depending on the sound generator somewhere between 19.5 and 20.5 I would notice it go substantially silent. Now as I have gotten older I have noticed that I can't hear much above about 17.5.
Anyway, the range of human varies with age, and does so noticeably with men in the high frequency range. Also, its possible that some people have a wider range of hearing atleast at the peak level of their physical development. All of that being said, who knows what odd frequencies can be generated by a VFD.
Hmmmm... I'm not sure any of that makes a point, but its some nice anecdotal information to consider. LOL.
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wrote:

Female voices are predominately high frequency.
Men, as we age, tend to lose our hearing at high frequencies first.
Coincidence?
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On Wed, 21 Aug 2013 13:44:08 -0400, Spehro Pefhany

Survival.
"
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Bob, I used not to be comfortable in a room with a TV which had a loose bracket on the flyback transformer. The 17.5KHz deflection frequency literally drove me out of the room!
At 64, I can't hear much above 10KHz, and suspect that's diminishing due to my fireworks and explosives activities (and Viet Nam, where I had an eardrum perforated by a nearby and unexpected firing of a Browning .50).
Lloyd
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On Wed, 21 Aug 2013 12:59:55 -0500, "Lloyd E. Sponenburgh"

Try having a claymore go off over your hide. Takes out both eardrums. Trust me.
"
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I've been within 20M of them on the (so-called) 'safe side'. Yeah, they're loud, even when you're hunkered-down below the projectile path.
Lloyd
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On Wed, 21 Aug 2013 14:04:31 -0500, "Lloyd E. Sponenburgh"

Im fortunate I can still hear..mostly. I have however gotten pretty good at lip reading most women. I can hear their voices..I just cant make out what many say. Way above my hearing range.
I had my hearing checked by a pro a few years ago..and he had the chart with my hearing range in his hand..he looked up at me...looked at the chart..and said..let me guess..combat vet right?
The chart had holes in the hearing ranges all over the place. He said only combat vets have a chart that looks like it was hit with a shotgun a couple times..with scattered holes all over it. Its been years since Ive heard a violin.
Shrug.
"
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"Lloyd E. Sponenburgh" wrote:

15,734.34 Hz for color, 15,750 Hz for B&W. The reason for the difference is to eliminate a color beat, but allow existing TVs to see color broadcasts.
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yep, flipped a couple of digits.
And... it was back in the BW days, when I was young enough to hear that frequency.
We didn't have color TV until about three years after I got married! (don't say it... no, I didn't know Marconi, except by reputation!) Lloyd
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12:06:15 -0400 typed in rec.crafts.metalworking the following:

    Some people are more "perceptive" than others. The effect of fluorescent light bulbs for some folks is not "illumination" but "disco strobe light" - which makes concentrating in school or at work "difficult".
    Tangent question - AM radio reception in a pickup truck. ('98 Mazda, EFI, manual 244000 miles)
    I leave 'near' Everett WA, twenty miles as the seagull flies from Paine Field (a bit farther if the seagull is driving and stuck in traffic.) I cannot believe that I live so far out in the boonies, that I can't pick up local radio stations. (At night - the two strongest stations are in Calgary and Vancouver BC. Kind of tough to figure the local weather from their reports - in Celsius, no less. But I digress.)     Regardless, and I realize diagnosing electrical troubles by mail is right up there with getting financial advice on the radio and other forms of occult prognostication, I have noticed a couple things. I get over the ridge - and past the high-tension power lines - and I can generally get the Seattle Stations. But sometimes, especially when I tune to ~550 AM, I get a "sound" - sort of like a marlin Brando clearing his throat on sideband. a sort of 'pop' - gargle, 'pop' - gargle, 'pop' - gargle,'pop' - gargle', pop' - gargle.     It isn't (as far as I can tell) related to engine speed - in fact I can shut off the engine, energize the circuit and the radio is clear, then pop the clutch, resume engine running - and no pop-gargle. Also, on occasion I have "joggled" the key - returning it back to the proper detent for "engine is running", not part way to "engage starter solenoid!" - it has cleared up. For a while.
    Now with that collection of wonderfully accurate set of technical descriptions, no doubt you can channel the mighty psychic powers of the Late Great Carnac and know exactly what is the source of my woes. (Aside from the County PUD.) And what the solution is, aside from "Plug the ipod in and listen to that instead."
thanks in advance.
pyotr
-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."
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On Thu, 22 Aug 2013 11:10:05 -0700, pyotr filipivich

Try removing your instrument fuse - see if it goes away. Don't know what kind of instrument regulator they are using theses days, byt they used to use a thermal unit that could (and often did) make terrible noise on AM radio. I replaced quite a few with solid state regulators over the years. (no, the dash instruments do NOT work on 12 volts) If the BZZ POP BZZ POP goes away with the instrument (not instrument lighting) fuse pulled, you know where to look.
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snipped-for-privacy@snyder.on.ca on Thu, 22 Aug 2013 16:21:00 -0400 typed in rec.crafts.metalworking the following:

    Thanks, an option to follow up on. -- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."
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