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  1. #61
    Member Iron-Man's Avatar
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    Default Re: Motors for small production machine.

    Quote Originally Posted by strantor View Post
    Nice! Similar story...

    I'm a Controls Engineer; I design control systems for industrial process equipment (conveyors, palletizers, extruders, etc.) and CNC is more of a hobby. But people usually assume I'm some sort of "whiz" or "hacker" and throw random stuff at me. Just so happens I had a customer with a Denford NovaTurn he got at auction. He couldn't run it because it didn't come with the license floppies. He sent me home with the PC and wanted me to "hack" it. I told him I would evaluate it and see if what could be done. I spent a couple of hours and came to the conclusion that it needed a retrofit. I offered to quote him, told him it would probably cost more than the machine was worth, and of course he declined. I think he sold it on eBay. Maybe you bought it?

    I purchased my machine back in 2014. It had no computer, control box, turret or disks. Just the machine.
    I have been searching for the Denford Turret for years with no luck. One came up on ebay a few months ago but was purchased by someone immediately.
    I finally have a back turret in which I am working on a lathe control board and a 8 position encoder using hall-effect devices, interface. It looks just like the one in the video except it has a stepper motor. The turret was made by David Decaussin, I believe:

    It is bi-directional, I may change to a brushless or AC servo.

    Iron-Man

    Last edited by Iron-Man; 01-20-2021 at 09:52 PM. Reason: 8 position encoder etc.


  2. #62
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    Default Re: Motors for small production machine.

    Quote Originally Posted by strantor View Post
    Yes I've approved a quote from DMM for a pair Dyn4 packages, just waiting on an invoice.
    Good move.

    Packaging in an enclosure will be easier, and the Dyn4's can run the servo to higher speeds. I believe the latest DYN4's don't require the irritating add-on logic filter anymore as it's now internal - good move on their part.

    All you'll need is a little DIN rail PS for the Mesa, and maybe a 24v one if you want to have all the field signals & control wiring be more noise resistant. No big 48/60vdc PS to mount.

    The DYN4 instructions indicate needing a line reactor for each drive, but I've had success in three installations with a single big one between the MCB and the 240VAC distribution block. Again, easier packaging/installation in an enclosure.



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    Default Re: Motors for small production machine.

    Quote Originally Posted by spumco View Post
    The DYN4 instructions indicate needing a line reactor for each drive, but I've had success in three installations with a single big one between the MCB and the 240VAC distribution block. Again, easier packaging/installation in an enclosure.
    Yes I saw that. I'm not a believer yet.

    In my line of work I deal with VFDs & induction motors quite a bit. Servos I run across occasionally, but the vast majority are VFDs. All the VFD manufacturers recommend an input reactor but usually that recommendation goes unheeded. It seems with servos it is delivered as a stipulation more often than a recommendation, and often they up the ante by specifying a full blown sine/noise filter, yet still I encounter servo installations with neither.

    They're supposed to protect the drive from mains anomalies, but I've encountered bricked VFDs with reactors just as often as without. It's usually lightning strikes that do it, and I've never seen a failed drive that I had reason to suspect was killed by local mains transients other than lightning strikes, and a reactor won't protect against lightning strikes.

    They're meant to "slow down" current/voltage spikes between mains and drive, and that works in both directions. So having a single reactor with multiple drives downstream [educated guess] could create a situation where spikes caused by one drive regenerating could be higher at the input terminals of the other drives than they would have been with no reactor at all, since those spikes can't be absorbed by the mains as fast. [/educated guess]

    In DMM's own demonstration videos they are not using any reactor or filter (at least not in any that I've seen). In their multi-axis kits, none is provided. Until I encounter nuisance trips or hear horror stories about these drives causing EMI disturbances, I plan to forego the reactor entirely. I will leave room in the cabinet for them in case I find they are needed, but I'm not investing in them before I know they're absolutely necessary.



  4. #64
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    Default Re: Motors for small production machine.

    Hi,
    99% of line reactors are three phase, so just use one coil for each of your drives, if you use one at all.

    This is an example of a very modestly priced 6A 6.2mH three phase reactor:

    https://nz.element14.com/block/lr3-4...line%20reactor

    Note that Element14 is an international company called Farnell in the UK and Newark is the US, so if you search in your area you will get a price in your local
    currency.

    It may well be a 'storm in a teacup' in any event. The current distortion that occurs with rectifier/capacitor devices gets worse as the power level increases, so much so that a VFD,
    for example, delivering 2.2kW to a load will be presenting serious distortion to the AC supply. Two or three servos drawing a couple of hundred Watts each will pollute the
    supply to a vastly lesser degree, so that line reactors while preferred and recommended are not strictly required.

    My servos are 750W, and very occasionally they will draw all of that 750W and sometimes as much as 2200W in overload but the average power is very much less.
    You really have to push your machine for the servos to soak up more that 100W each. So excepting those peak demands line reactors are not really an issue.

    I also use a 1.8kW servo as a spindle motor and when machining steel can regularly get average power levels of 1kW and more. For that drive I will add a line reactor as I've had that
    spindle generate enough noise to give me controller 'Run Out Of Data' faults.

    Craig



  5. #65
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    Default Re: Motors for small production machine.

    Hi,
    VFDs and servo drives draw current in very short high intensity pulses, and those pulses distort the voltage waveform which can upset other equipment powered
    from the same mains supply.

    The current distortion causes higher than normal losses in the wiring circuits and distribution transformers so electrical supply companies will insist you fit a reactor, or its
    electronic equivalent, if your device is causing problems in your area. This is most likely to happen with high power (20kW plus) installations rather than servo
    drives of a few hundred Watts..

    Here in New Zealand we have seen an explosion in the use of down-hole pumps up to 300kW for irrigation. Farmers moan and whinge that they have to fit
    reactors (or electronic equivalent) as the reactors can be a substantial fraction of the cost of the installation. The power companies insist otherwise everyones
    (in rural areas...like me) PC, TVs and microwaves blow up all the time.

    If you have several single phase devices all powered off the one AC circuit they will ALL draw their current pulses AT THE SAME TIME, because the pulses occur
    at double the frequency and in phase with the AC supply. One large reactor would be sufficient to 'tame' the current drawn by all the devices. As I posted earlier
    a three phase reactor has three coils and thus you could use one coil per drive if you are concerned.

    Craig



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    Default Re: Motors for small production machine.

    Quote Originally Posted by joeavaerage View Post
    Hi,
    99% of line reactors are three phase, so just use one coil for each of your drives, if you use one at all.
    Interesting idea, it had never occurred to me. I will give it a try since I do have some 3ph reactors in my cache. I wonder if it would be an improvement or if it would exacerbate the issue by inductively coupling spikes from one drive to all of them. I also have some DC chokes I can try (if inductance specs are close). This has got me curious now. I'm out of state on work, but when I get home (2-3 weeks) I will scope the mains input during operation with no reactor, with a dedicated reactor per drive, with multiple drives on a single reactor, and with the DC chokes. Will see if there is any real concern and if any of these solutions effectively address it.



  7. #67
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    Default Re: Motors for small production machine.

    Of all the industrial installations I have done involving VFD's, I have never used a 3ph choke on the input side, the input to just about all VFD's is a 3p rectifier and a large capacitor bank, So it virtually absorbs any spikes etc.
    I have however used them many times on the output of the VFD, especially where the motor is a older non-VFD rated type, one engineer from a large VFD manuf. told me that he preferred the set up as it was beneficial to both motor (H.F. spike suppression) and to VFD.
    I did attend a seminar by the provinces power supplier on the virtue of choke on the VFD inputs in large industrial plants to improve P.F. and save on power costs as about the only advantage.
    Al.

    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.


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    Default Re: Motors for small production machine.

    Quote Originally Posted by Al_The_Man View Post
    Of all the industrial installations I have done involving VFD's, I have never used a 3ph choke on the input side, the input to just about all VFD's is a 3p rectifier and a large capacitor bank, So it virtually absorbs any spikes etc.
    I have however used them many times on the output of the VFD, especially where the motor is a older non-VFD rated type, one engineer from a large VFD manuf. told me that he preferred the set up as it was beneficial to both motor (H.F. spike suppression) and to VFD.
    I did attend a seminar by the provinces power supplier on the virtue of choke on the VFD inputs in large industrial plants to improve P.F. and save on power costs as about the only advantage.
    Al.
    Yes, output reactor is a different story. I use them any time lead length from VFD to motor are excessive, or if motor is not inverter duty.



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    Default Re: Motors for small production machine.

    Hi,
    filters on the output side of the VFD are indeed a different kettle of fish and you should follow manufacturers spec TO THE LETTER or risk
    blowing the output IGBTs.

    Line reactors are used on the input side, hence the line in line reactor.

    The purpose is to improve power factor and decrease the stress on the supply, particularly excessive heating of the wiring
    and distribution transformer. If you don't care about what your machine does to the quality of the input supply, or the potential
    increased heating of the wiring in your house then don't bother with line reactors.

    In New Zealand its covered by:

    https://www.worksafe.govt.nz/laws-an...s-of-practice/

    And that Code of Practice has legal teeth in the following IEC regulations:

    IEC 61000-3-2
    IEC 61000-3-3
    IEC 61000-3-12

    The IEC standards underpin the Harmonic Current limits regulations all around the world.

    virtue of choke on the VFD inputs in large industrial plants to improve P.F. and save on power costs as about the only advantage.
    The power supply company will insist that you control harmonic currents otherwise they are within their rights to deny to connect you.........that
    is a distinct advantage of using reactors.

    the input to just about all VFD's is a 3p rectifier and a large capacitor bank, So it virtually absorbs any spikes etc.
    It is BECAUSE of the rectifier/capacitor bank that current IS DRAWN in pulses or spikes.

    In the attached pics are a simple single phase rectifier and capacitor driving a 20 ohm load. Note that the average output current is about 16A but
    particularly in the RectifierCapacitor pic the peak current drawn from the supply is 100A. The same circuit but with a 10mH reactor in-line
    reduces the current peak to just over 30A, a marked improvement, but still quite high.

    Craig

    Attached Thumbnails Attached Thumbnails Motors for small production machine.-rectifiercapacitor-jpg   Motors for small production machine.-rectifiercapacitorinductor-jpg  


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    Default Re: Motors for small production machine.

    Hi,

    I wonder if it would be an improvement or if it would exacerbate the issue by inductively coupling spikes from one drive to all of them.
    You are right to be concerned. If you phase the coils incorrectly a current spike in one coil will induce another spike in another coil. At worse
    what happens is the two coils effectively cancel each other out, but no smoke is emitted. If you phase the coils correctly then they work
    as intended.

    As the pics have showed the timing of the current pulses is determined by the input AC frequency, and as all drives share the same AC supply ALL the
    current pulses occur at the same time, thus whether you use one high current coil for all drives or lower current coils for each drive is not important, more
    a matter of style than substance.

    Depending on the impedance of your supply at home I doubt you will see any waveform distortion as a result of a couple of servos, a 5kW spindle motor
    running at full output will however. In design calculations engineers use a phrase 'per phase line impedance'. We imagine that the AC power is delivered to us
    without restriction....of course its not the case. The power supply voltage will sag if you draw enough current, hence the term. In New Zealand we use
    a 'per phase impedance' of 100 mOhm in series with a 5mH inductance. In most developed nations that would be fair. If you live in a rural area remote from the
    distribution transformer then you might expect a higher 'per phase impedance'.

    https://www.sciencedirect.com/topics...nic-distortion

    Craig



  11. #71
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    Default Re: Motors for small production machine.

    Keep in mine that 3ph inductive chokes on the output increases the inductive reactance and suppresses harmful (especially to the motor) H.F. H.V. spikes.
    In the 40 odd years I have been using & installing VFD's I have never heard of any reported failures.
    Never yet used one on the input,
    I used to buy Mitsubishi VFD's by the pallet.
    Al.

    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.


  12. #72
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    Default Re: Motors for small production machine.

    Quote Originally Posted by joeavaerage View Post
    Hi,
    filters on the output side of the VFD are indeed a different kettle of fish and you should follow manufacturers spec TO THE LETTER or risk
    blowing the output IGBTs.
    Blowing output IGBTs? I've never heard that, or seen output reactors suggested as a means of protecting the drive. According to my knowledge, output reactors are to protect the motor. Long lead lengths can cause harmonics to be amplified at the motor, causing insulation breakdown at the motor. According to what I've read.

    Quote Originally Posted by joeavaerage View Post
    Line reactors are used on the input side, hence the line in line reactor.

    The purpose is to improve power factor and decrease the stress on the supply, particularly excessive heating of the wiring
    and distribution transformer. If you don't care about what your machine does to the quality of the input supply, or the potential
    increased heating of the wiring in your house then don't bother with line reactors.
    I have little doubt that you could cite scholarly articles that agree with what you've just said, but that's because it's more academic than practical. I can attest to having seen many hundreds (no exaggeration) of multi-kW VFDs operational in the field, installed with no line reactor, which did not melt feeder circuits inside of their conduits (and zero which have). The heating in the wires (and the thermal overloads/breakers/fuses, which all operate on the same principle, current = heat) is described by (I^2)T. The current, being a square, is more heavily weighted than time so technically high current pulses of an average equal to a sinusoidal current would generate more conductor heat than the sinusoidal current would, but they would also generate the same elevated heat in all upstream overcurrent devices. So yeah, they might generate more heat in the wires, and if they did, they would be proportionally just as likely to trip a breaker as a result. If wires are burning up in your house, it's because your breakers are sized improperly; not because your device is drawing non-sinusoidal current.

    Quote Originally Posted by joeavaerage View Post
    In New Zealand its covered by:

    https://www.worksafe.govt.nz/laws-an...s-of-practice/

    And that Code of Practice has legal teeth in the following IEC regulations:

    IEC 61000-3-2
    IEC 61000-3-3
    IEC 61000-3-12

    The IEC standards underpin the Harmonic Current limits regulations all around the world.
    Thanks for bringing that up. It is important to keep abreast of international standards as I might one day wish to sell these outside the country. Curiously though, many European import machines I have serviced, did not have line reactors on the drives. They may have been built for export and to American standards.

    Quote Originally Posted by joeavaerage View Post
    The power supply company will insist that you control harmonic currents otherwise they are within their rights to deny to connect you.........that
    is a distinct advantage of using reactors.
    I've never heard of the utility company enforcing any harmonic currents policy. Power factor, yes. For industrial/commercial customers. And VFDs are often marketed as power factor correction devices, as they rectify, AKA draw current in phase with voltage. As opposed to an unloaded or partially loaded induction motor powered directly from mains, which has a horrible power factor.



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    Default Re: Motors for small production machine.

    Hi,
    perhaps you'd prefer an American publication on the matter:

    file:///C:/Users/User/Downloads/harmonics_and_ieee.pdf

    Craig



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    Default Re: Motors for small production machine.

    Quote Originally Posted by joeavaerage View Post
    Hi,
    perhaps you'd prefer an American publication on the matter:

    file:///C:/Users/User/Downloads/harmonics_and_ieee.pdf

    Craig
    IEEE is an international provider of academic guidance and recommendations, compliance is voluntary. In the US, law regarding electrical distribution is NEC/NFPA, which has this to say:

    The National Electrical Code (NEC) uses the word “harmonic” exactly 11 times, all in combination with or explanation of neutral conductors. However, “harmonic” is not defined in the NEC. A definition of the word is located in 3.3.44 and used in 10.1.1.8 in the 2010 edition of NFPA 70B, the Recommended Practice for Electrical Equipment Maintenance: “those voltages or currents whose frequencies are integer multiples of the fundamental frequency
    https://www.ecmag.com/section/codes-...erfect-harmony

    We acknowledge its existence and that's about the end of its practical relevance. There is no law about it that I'm aware of, until the frequencies get into the RF spectrum, and then FCC steps in.



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    Default Re: Motors for small production machine.

    This discussion felt eerily familiar despite my being quite sure I've never engaged it before. Then I realized it's a dead ringer for the covid/mask debate, so there's probably a good chance of it getting ugly if we let it.

    Person A: "why aren't you wearing an input reactor?"

    Person B: "because they're ineffective, uncomfortable, and this is a free country and you can't make me."

    Person A: "input reactors HAVE proven effective against the distribution of harmonics"

    Person B: "well if you're so worried about harmonics then YOU wear a reactor and leave me alone."

    A: "firstly, I AM wearing a reactor. Secondly, the reactor is not to protect one's self, but others around them."

    B: "well I'm not emitting any harmonics so I don't need a reactor."

    A: "you don't KNOW that you're not emitting harmonics so it's best to wear a reactor just to be safe."

    B: "YOU don't KNOW that I AM emitting harmonics. I don't live in fear. Harmonics aren't as scary as what your media is telling you. Reactors don't work. I'm not wearing one."

    A: [posts link to scientific research paper from prominent authority, overstating the threat of harmonics and the efficacy of reactors]

    B: [posts link to scientific research paper from equally prominent authority, understating the threat of harmonics and efficacy of reactors]

    A: "It's the law"

    B: "not in my country"

    <WE ARE HERE>

    A: "you're obviously an obtuse science denier"

    B: "YOU're obviously an obtuse science denier"

    A: "you're obviously an inconsiderate idiot."

    B: "you're obviously a frightened sheep."

    A: "idiot!"

    B: "moron!"


    Let's not debase ourselves to the level of the mask debate.

    Last edited by strantor; 01-23-2021 at 09:07 AM.


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    Default Re: Motors for small production machine.

    Hi,
    indeed is was going to make a not so polite reference to the same point.

    There is considerable science indicating that rectifier/capacitor input devices produce harmonics which degrade the AC supply quality locally.
    Even if you don't really care about the quality of the supply or difficulties that the line supply company it is highly probable that harmonics generated
    buy one piece of equipment, a servo or VFD say, conducts that noise into other devices connected locally like PCs, and motion controllers.

    And VFDs are often marketed as power factor correction devices, as they rectify, AKA draw current in phase with voltage. As opposed to an unloaded or partially loaded induction motor powered directly from mains, which has a horrible power factor.
    Then why do VFDs have such a poor power factor? They may draw current in phase with the voltage but the current distortion badly and negatively affects power factor.

    This is from Yaskawa:

    A good way of understanding power factor is to consider the equation:
    Power Factor = Cos theta/(theta[1 + THD2])
    where: theta = displacement angle between fundamental voltage and current
    THD = total harmonic current distortion
    The above equation takes into account fundamental displacement and harmonics. Both affect true
    (overall) power factor.
    Craig



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    Default Re: Motors for small production machine.

    Quote Originally Posted by joeavaerage View Post
    Then why do VFDs have such a poor power factor? They may draw current in phase with the voltage but the current distortion badly and negatively affects power factor.

    This is from Yaskawa:



    Craig
    I am glad you picked Yaskawa as a reference. I couldn't have picked a better source of information on this topic. I used to work field service for a Yaskawa distributor and had/got to sit through many of their trainings. Still some of the best VFDs out there in my opinion even though I'm no longer tied to them. Yaskawa is who I had in mind when I said "VFDs are often marketed as power factor correction devices."

    Here is some of the technical marketing literature from Yaskawa that I had in mind. I'll excerpt the parts that answer your question but I consider the entire document recommended reading.

    VFDs can be used to improve system power factor when oversized motors or motors that
    operate at low power factor are used.

    [...] (already quoted by you)

    A motor operating directly from a sine wave supply (commonly referred to as “across-the-line” operation) will exhibit displacement between the applied voltage and resulting current. The displacement varies as the motor load changes. Typical values for displacement, Cos ?, are 0.85 for heavily loaded motors and 0.65 for moderately loaded motors. Lightly loaded motors may appear as pure inductors in which the power factor is nearly zero.

    [...]

    Diode, and sometimes IGBT based rectification keeps the input fundamental displacement near unity. In other words, drive input current remains in phase with the supply voltage under all load conditions. Therefore, Cos ? is near unity (approximately 0.98) with VFD use. On the other hand, diode and IGBT rectification may result in relatively substantial current THD. A typical full wave diode bridge rectifier will result in approximately 45% current THD. This is a typical value for a VFD with DC link choke under fully loaded condition. Using 0.98 for displacement (Cos ?) and 0.45 for THD in the above equation, the resulting PF will be
    approximately 0.89.

    [...]

    Under light loading, drive input displacement power factor remains near unity due to the diode rectification. However, VFD input current THD will increase. It is not uncommon for THD to be near or even above 100% under lightly loaded conditions. Applying a large THD to the above equation results in substantially reduced power
    factor. However, this in itself is not as bad as it may seem.

    [...]

    Current THD increases partially because the harmonic component increases, but, also because the fundamental component decreases. THD increases to what appears to be a significant level, but, the actual overall harmonic current component itself is quite small as compared to the full load current. Overall, VFD input current will be nearly zero as the largely reactive current flowing into the lightly
    loaded motor does not get reflected back to the supply.

    [...]

    Only the real (torque producing) component is measured on the supply side. Even though drive input PF is lower due to increased harmonics at light load, the input current is also much lower. Subsequently, the low input power factor does not negatively impact the overall supply components (transformer, wiring, etc.) that are already sized to accommodate full load operation in the first place. Over sizing of supply components that is typical for low power factor systems is not required because the VFD input current is also low
    Then at the end of the document it says this:

    In conclusion, consider using a PWM based VFD that offers a DC link choke or some other form of power factor improvement such as an input line reactor when power factor improvement is desired. Effective utilization of energy can be maintained even when motors are oversized to accommodate future production increases. Lower overall input current to the VFD/motor system and improved overall “system” power factor can be realized. This will result in lower utility charges.
    What it says nowhere in there is "You SHALL use an input line reactor any time there might be harmonics induced (which is always) or else risk damage to nearby electronics, structure wiring, distribution transformers, and the electrical grid."

    Last edited by strantor; 01-23-2021 at 06:10 PM.


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    Default Re: Motors for small production machine.

    Hi,

    What it says nowhere in there is "You SHALL use an input line reactor any time there might be harmonics induced (which is always) or else risk damage to nearby electronics, structure wiring, distribution transformers, and the electrical grid."
    You are quite correct, I have not read in any of the Yaskawa stuff that I've read that you must use a line reactor, just that it is one means to secure a better power factor.
    There are other publications that talk more about the extra heating in distribution transformers....but are you interested in what the power supplier has to put up with?

    I would have thought more of a concern that other equipment, your own, could be at risk because of the current distortion and certainly possible that the electrical noise
    interferes with your CNC controller. If you are not concerned about that then neither am I.

    What intrigues me is that if you look on DigiKey, Farnell, Mouser and RS you will see page after page of listings for three phase reactors. If, as you contend, they are
    unnecessary then why are there so many listings? Surely all those manufacturers would go out of business if your contention were 100% correct?

    Whatever....

    Craig



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    Default Re: Motors for small production machine.

    Quote Originally Posted by joeavaerage View Post
    Hi,



    You are quite correct, I have not read in any of the Yaskawa stuff that I've read that you must use a line reactor, just that it is one means to secure a better power factor.
    There are other publications that talk more about the extra heating in distribution transformers....but are you interested in what the power supplier has to put up with?

    I would have thought more of a concern that other equipment, your own, could be at risk because of the current distortion and certainly possible that the electrical noise
    interferes with your CNC controller. If you are not concerned about that then neither am I.

    What intrigues me is that if you look on DigiKey, Farnell, Mouser and RS you will see page after page of listings for three phase reactors. If, as you contend, they are
    unnecessary then why are there so many listings? Surely all those manufacturers would go out of business if your contention were 100% correct?

    Whatever....

    Craig
    I would be more concerned about other electronics if I had ever seen them fail as a result of drive-induced harmonics. But as I said, I have been working with VFDs* for many years and have never seen it. I've seen communications devices fail from EMI on comms busses induced by drive outputs when unshielded cables were used, but not harmonics on power input.

    * I have (and will again) acknowledge that I have much less experience with servos and have noted that servo manufacturers guidance on input reactors seems more strict than for VFDs, for reasons I haven't worked out yet. I still don't know if all this VFD talk is relevant; if we are talking apples to apples. As I said, I am leaving room in my panel and in my mind, for the possibility of needing reactors. It is worth noting that my mill has a 2.2kW servo spindle drive, no reactors, and I've never had an issue with my LinuxCNC controller.

    As to why 3ph reactors are so readily available, "line" vs "output" reactors differ only in the label that's adhered to them after they're manufactured (if such label is adhered at all). Output reactors are much more commonly used. Quite often they are absolutely needed, and I absolutely use them when they are.

    As for my level of concern for the utility company, I have little because I have little incentive. They don't complain about it nor penalize for it. Apart from what you've said, I've never heard of it being a problem. I've never heard of an electrical consumer penalized specifically for harmonics. Just power factor, of which harmonics can be a component. If someone is concerned with it, they can add a reactor, or order their machines with reactors installed. It's an option you can specify with an OEM when they spec a machine.

    Last edited by strantor; 01-24-2021 at 09:15 AM.


  20. #80
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    Default Re: Motors for small production machine.

    Just for S&Gs I toured the plant I'm working at today and took some pictures of various VFD and servo installations to illustrate the common use (or lack thereof) of input reactors from various manufacturers around the world and from various dates of manufacture.

    #1 Beumer palletizer:
    -made in Germany, circa ~2010
    (1) 50kW servo with input sine filter.
    (2) 2kW VFD, no input reactors or filters

    https://www.cnczone.com/forums/attac...d=457256&stc=1 https://www.cnczone.com/forums/attac...d=457258&stc=1

    #2 Wulftec stretch wrapper
    -made in Canada, 2020
    (7) 1.5kW VFDs
    (1) 5kW VFD
    (0) reactors or filters

    https://www.cnczone.com/forums/attac...d=457260&stc=1

    #3 Windmoller & Holscher bagger machine
    -made in Germany, circa ~2010?
    (4) servo drives
    (0) reactors or filters

    https://www.cnczone.com/forums/attac...d=457268&stc=1

    (Those are transformers up top for resistive heating strips)

    #4 Windmoller & Holscher bagger machine
    -made in Germany, circa 2019
    (6) servo drives
    (2) VFDs
    (0) reactors or filters

    https://www.cnczone.com/forums/attac...d=457274&stc=1
    (Same story with the transformers up top. And there are two tiny input filters beside the transformers, these are for the resistive heater controllers)

    #5 Windmoller & Holscher palletizer
    -made in Germany, circa 2019
    (5) sub-10kW servo drives, no filters or reactors
    (1) 50kW servo drive with reactor and sine filter

    https://www.cnczone.com/forums/attac...d=457280&stc=1

    #6 Lachenmeier hooder
    - made in Denmark, 2020
    (2) VFDs
    (0) reactors or filters

    https://www.cnczone.com/forums/attac...d=457282&stc=1

    Hopefully this helps illustrate the difference between the real world and the world of whitepapers and textbooks.

    Attached Thumbnails Attached Thumbnails Motors for small production machine.-20210124_101555-jpg   Motors for small production machine.-20210124_101615-jpg   Motors for small production machine.-20210124_095009-jpg   Motors for small production machine.-20210124_095659-jpg  

    Motors for small production machine.-20210124_095844-jpg   Motors for small production machine.-20210124_100013-jpg   Motors for small production machine.-20210124_100425-jpg  


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