Is my setup right? 1.5HP 3ph 220V Motor. 120V VFD Input
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    Default Is my setup right? 1.5HP 3ph 220V Motor. 120V VFD Input

    Hello, I'm new around here as I have been searching high and low for information about this and it seems difficult to find accurate information out there.


    I recently bought a 10 5/8" squirrel cage blower with directly attached 1.5HP motor. I have been reading more into it and I believe to power my motor correctly I would need a VFD to convert the power coming in from single phase 120V to 3 phase 220V.

    I'm new to electrical and motors so if someone could let me know if I'm on the right track or not that would be great!

    (Also, I know it's supposed to be 1 question per thread but if someone could slip in the HOW a VFD can step-up up 120V to 240V that would be cool as well)

    1ph 120V Input to VFD 3 ph 240V to motor?
    Motor Plate
    motor-specs.jpg
    60 Htz
    1.5 HP 1750 RPM
    3ph
    208 - 230 / 460 V
    4.8-4.8/2.4 FL Amps
    5.2/2.6 SE Amps



    Thank you!

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    the vfd has a voltage doubling rectifier on the front end.

    for less than 300$ you could just buy a single phase 120/240v motor.

    also, the power factor of a vfd is rather horrible. you will need a 30 amp 120v circuit to drive it, and the cost and time of getting that is probably less than the cost and time of wiring a 230 volt circuit and buying a regular vfd.

    you can take your chances trying to run it on a 20 amp circuit breaker but you will likely need to choke the fan down to lower the load, or run the motor at a lower frequency (fans have a cubic power curve)

    then again if the motor only needs to deliver 1 hp, then a 15 amp circuit will theoretically do it.

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    Quote Originally Posted by FullMe7alJacke7 View Post
    Hello, I'm new around here as I have been searching high and low for information about this and it seems difficult to find accurate information out there.


    I recently bought a 10 5/8" squirrel cage blower with directly attached 1.5HP motor. I have been reading more into it and I believe to power my motor correctly I would need a VFD to convert the power coming in from single phase 120V to 3 phase 220V.

    I'm new to electrical and motors so if someone could let me know if I'm on the right track or not that would be great!

    (Also, I know it's supposed to be 1 question per thread but if someone could slip in the HOW a VFD can step-up up 120V to 240V that would be cool as well)

    1ph 120V Input to VFD 3 ph 240V to motor?
    Motor Plate
    motor-specs.jpg
    60 Htz
    1.5 HP 1750 RPM
    3ph
    208 - 230 / 460 V
    4.8-4.8/2.4 FL Amps
    5.2/2.6 SE Amps



    Thank you!
    At a mere horse and a half, and in the common-as-dirt tree-rat cage blower tribe, it should be faster, cheaper, and less hassle to record the motor frame (mounting match wanted) and shaft type, length, size and find a source less rapacious than W.W. Grainger to swap-in a 1-P motor in the voltage you have handy - whichever it is.

    Unless you NEED more "variable" as to speed than the common-as-dirt multi-speed tapped blower motors Grainger and others sell all day, every day to the HVAC maintenance industry.

    Adding a VFD to the mix if not absolutely needed can complicate the rest of yer life, if not also your budget. Might be cheapest of all to horse-trade that blower for one already "turn key", not have to mess with anything more complicated than bolting it up and ducting it. Or whatever.
    .

    Most especially as VFD as can "Voltage Double" tend to command a premium price as well as being de-rated as to power they can haul when run in that mode.

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    Looks like you are on the right track, VFDs are easy to set up, they are jellybean parts like the motor. Are you going to use the motor for cooling as is? If your going to use it to cool (low load) it is not going to pull a lot current. However if you are going to be driving a Larger load then things change.
    I am not sure why Johansen mentioned the 30 Amp breaker (please explain the reason Johansen.) seems like a lot of Amps for a cooling app. I cannot make out some the specs on the info plate.
    such as delta or y configuration.
    I would do the following:
    A)Determine the application.
    B)What will be the load?
    C)Call the folks at Automation Direct, they will be able give you the best VFD for your requirements.
    D) Go on utube and there you will find some very good info on how VFDs work plus what all those designations on the motor mean.

    I have a VFD running the tool changer on a VMC. and I am no where near 30A, bearing mind tool changer is an intermittent load situation.

    Don't re-invent the wheel, let Automation direct run the numbers
    then see where you are.
    JUST MY .02 best of luck.
    Last edited by doug8cat; 10-06-2019 at 04:14 AM. Reason: ETOH

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    @doug8cat it will be used either for A) Laminar Flow Hood most likely, but my backup plan if it ended up pushing too much or not enough air for that was to use it as a mycology room exhaust to control the humidity in combination with a misting system. (Mist the air for a bit then turn on the exhaust to ensure fresh air exchange and dry it back out, simulates rain for fungi)

    Depending on the total cfm I end up with coming from the fan; It seems it would be easier and cheaper to just buy a single phase 120v motor that would be strong enough to run a squirrel cage large enough to put out 100 cfm through a larger (8 sqft) HEPA 0.3 micron filter with 1 wg of pressure.

    Not sure what the load would be, the VFD I linked above was recommended by the customer service from precision electric for the motor after I sent them the specs on the plate.

    I have been watching Jeremy Fielding's youtube series on motors, among other channels about general electrical.

    I found the motor and blower I have now, online for $60 and 10 minutes from my house so I might of impulse bought before I knew enough about motors to make the correct decision.

    @Johansen I am also curious on why I might need a 30 Amp breaker?

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    Quote Originally Posted by doug8cat View Post
    I am not sure why Johansen mentioned the 30 Amp breaker (please explain the reason Johansen.)
    A 1.5 hp motor is probably 70% efficient requiring 1600 watts electrical input. this is 13 amps at unity power factor from a 120v circuit.

    Problem is the power factor of a voltage doubling rectifier is also on the order of .6 or so, so you will be pulling about 22 amps rms (but only 13 of which will spin the watt meter)

    so, you can probably get by with a 20 amp circuit.

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    I'll be honest I am not that familiar with 1 - 3 phase VFDs.
    A PF of 0.6 is rather low, PF is the lag in the sinusoidal curve (A/C) of current lagging voltage, or is it the other way round? Hell it is 10 to 5 AM here cu me a break.); Anyway costs the power co. more in infrastructure to cater to low PFs cause they bill on watts used.
    IMHO it would be better to get a 1ph motor to run that fan, less AGRO, less parts to fail, and ultimately probably cheaper.
    I have been down that road; Oh wow a bargain…... then you get to hooking it up and find that bargain just bit your ass right where your full wallet was. I could go about PF etc. but look at the entire picture.

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    To me it seems much easier to step up the 120volts to 220volts using a single phase transformer and then use a VDF to take it to 3 ph The slow start option comes at a bones and also adjusting the speed
    I often buy them used
    Transformer 1,5HP is about 1250watts So 1500 watts transformer should do using the slow start if need be

    Peter

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    Quote Originally Posted by doug8cat View Post
    I'll be honest I am not that familiar with 1 - 3 phase VFDs.
    A PF of 0.6 is rather low, PF is the lag in the sinusoidal curve (A/C) of current lagging voltage, or is it the other way round?
    The current is leading but the current only flows for 1 to 2ms of time between 160 to 180vdc at the top of the waveform.

    Google: powerfactor of singlephase rectifier.

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    Quote Originally Posted by Peter from Holland View Post
    To me it seems much easier to step up the 120volts to 220volts using a single phase transformer and then use a VDF to take it to 3 ph The slow start option comes at a bones and also adjusting the speed
    I often buy them used
    Transformer 1,5HP is about 1250watts So 1500 watts transformer should do using the slow start if need be

    Peter
    Anything under 2 HP - even 5 HP - US power distribution "fat" as it usually is even for residential service, there's not enough need nor gain as to be worth a lot of spend nor screwing about.

    For use as a dust collector, 'smith's forge booster, shop ventilator, or spray booth-extractor?

    Got a blower at a good price? Why throw GOOD money at it to make a problem out of a solution and queer the deal?

    Just hang a 1-P motor on it, flip the damned switch when yah need it, and go do something as actually needs a touch of brain-power.
    Last edited by thermite; 10-07-2019 at 06:49 PM.

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    I just mounted a 120V VFD to a 1.5HP 3-ph 220V metal lathe. Runs fine on a 20A circuit, plenty of power.
    The advantage of going to a VFD is variable speed. In addition, if you later on need to vary the speed by a thermostat or a PC -driven control, a VFD makes it easy.

    Just don't buy it from Grainger. Dealerselectric and a couple of others are much cheaper with excellent tech support.
    This is what I used:

    https://dealerselectric.com/DRIVE-T205.asp Out of stock here, but if you can find a closeout on it they go cheap

    You can also by the remote control panel for $20, which is a bargain

    It's possible you can get away with a 1 HP VFD just to run a fan. I doubt you need 1.5HP to run a 10" squirrel cage. A 1HP Teco is $150 shipped


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