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One Man's Junk is another man's Treasure

Susquatch

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Another note, there is a fair bit of chat about only using inverter rated motors with a VFD. I'm not and expert but from my limited experience and from what I have read here is the skinny on that topic:
compared to regular sinusoidal power that we get from the utility, the VFD produces a less than perfect waveform. The less than perfect waveform = some harmonics, greater voltage deviations etc. When using small motors 1.5-2HP @230V with less than perfect power the inverter rated hooplah is overrated because the 230V motor has 600V wire in it anyways etc. Now for larger motors for example 10HP and 600V operation than an inverter rated motor is probably a wise investment. I have been running a regular (very used) non inverter rated motor that came out of a commercial dryer for several years now and it's running like a champ, and from what I have read this is typical.

My simple version is that VFD Rated motors give you better control of damaging static on the bearings, better bearings for speeds above the rated rpm, and lower speed capabilities without overheating.

If using a non VFD Rated motor you might need a fan for cooling at low rpm and you shouldn't exceed 75hz on the high end.

VFD Rated motors come in many flavours usually described as a turndown ratio.

A good vfd rated motor can deliver full torque at Zero RPM (yes, 0 RPM) and can also run at 120Hz. That's what I bought for my mill. But I limited my minimum speed settings on my VFD to 6hz (180 rpm) and my max to 90hz (2670rpm)

The motor I bought for my lathe is only a 10:1 motor. So I can run it at 6hz to about 90hz. But I'll prolly only run it from 30hz to 75hz. That's plenty enough range for a lathe with a gearbox head.
 

Susquatch

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@Dusty - is your head spinning yet?

@dabblers advice is good.

Don't let the details from any of us turn you off. THIS IS A TRIP YOU WILL BE GLAD YOU TOOK! I PROMISE!

I'd love to hear from just one person who isn't glad they did it. Anybody?

Even a regular non VFD Rated 3ph motor and inexpensive VFD will feel 100x better than your old motor setup. If you stay within 20% or so of the rated frequency 60 +/- 20% you don't need to worry about all that other VFD rating stuff. If that isn't enough range for you, add a muffin fan on the end of the motor and run it down to 30Hz.

Don't forget that you still have belt changes if and when you ever need them!
 

DavidR8

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@Dusty - is your head spinning yet?

@dabblers advice is good.

Don't let the details from any of us turn you off. THIS IS A TRIP YOU WILL BE GLAD YOU TOOK! I PROMISE!

I'd love to hear from just one person who isn't glad they did it. Anybody?

Even a regular non VFD Rated 3ph motor and inexpensive VFD will feel 100x better than your old motor setup. If you stay within 20% or so of the rated frequency 60 +/- 20% you don't need to worry about all that other VFD rating stuff. If that isn't enough range for you, add a muffin fan on the end of the motor and run it down to 30Hz.

Don't forget that you still have belt changes if and when you ever need them!
I loved the VFD conversion on my LC-30 mill. It absolutely transformed it.
 

Dabbler

ersatz engineer
Just one more thing about cooling - I tend to run my mill for short cuts or drilling holes, etc. So cooling hasn't been an issue on the 2HP motor found on mills. I run down to 22hz and up to 90 hz on the non-VFD rated 'pancake' motor. Note these pancake motors are possible to run to 3600 RPM, but I have set mine for 'low speed'.

On my 1720 RPM that translates to about 640 to 2500 RPM, but I run the pulley so that ends up in the range of 400 to 1600 at the spindle. This is perfect for teh range of cutters I use - 1/8" to 3/4".

For me there's lots of time for the motor to cool and I never take heavy cuts needing high current in the motor, so your results may vary, depending on how you use your mill... I don't use a large face mill, and I don't fly cut often. When I do, I use the back gear and/or change the pully belt for that unusual occurrence.
 

Dusty

(Bill)
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@Dusty - is your head spinning yet?

@dabblers advice is good.

Don't let the details from any of us turn you off. THIS IS A TRIP YOU WILL BE GLAD YOU TOOK! I PROMISE!

I'd love to hear from just one person who isn't glad they did it. Anybody?

Even a regular non VFD Rated 3ph motor and inexpensive VFD will feel 100x better than your old motor setup. If you stay within 20% or so of the rated frequency 60 +/- 20% you don't need to worry about all that other VFD rating stuff. If that isn't enough range for you, add a muffin fan on the end of the motor and run it down to 30Hz.

Don't forget that you still have belt changes if and when you ever need them!

Posts started coming in zip, zip, zip my head was ina spin and my jaw bounced off the floor several times before my brain caught up to it.
All this information makes for positive reading and planning ahead then I check myself and say Dusty you old bugger you will be 86 years old this coming January 3rd, what are you thinking. LOL

Hopefully time is on my hands to look around before getting serious here.

So if I have it right I don't need to cal in an electrician to change the ehisting 230V wiring from my house panel to the outlet in my garage?

The switch to 3ph comes with the new motor etc., is updated somewhere after that. Am I correct with that in my little pea brain?

From the manufacture's name plate on my motor I cannot find the FRAME size, so now what?

Was going to change out the the V belts due to their age, 38 years come January 2024. That plan is on hold.

Thanks to everyone who ran a post or like to this thread.

Digging my hole deeper , shall be thinking this over all night long. LOL
 

Dabbler

ersatz engineer
So if I have it right I don't need to cal in an electrician to change the ehisting 230V wiring from my house panel to the outlet in my garage?
uh... perhaps. I'm not sure what changes you have in mind. (perhaps I have missed it)

The switch to 3ph comes with the new motor etc., is updated somewhere after that. Am I correct with that in my little pea brain?
Yes, you use a normal 220V plug, wired to a VFD box, and you have 3PH electricity wired from that box directly to your motor.

From the manufacture's name plate on my motor I cannot find the FRAME size, so now what?
Post a picture of your motor, and a picture of your motor plate. We can help you figure it out.
 

DavidR8

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My emotorsdirect.ca order history doesn't show the motor I bought.
That said, there is no frame size on my motor plate (I still have it) so I measured the mounting plate and the other data points that are called out on the motor spec sheets.
 

Susquatch

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Sometimes a picture is better than words. This does not show every detail for example there would also be a start and stop button connected to the VFD,

@Dusty - I like Slow Pokes idea of a picture. Your hookup doesn't even need the potentiometer because there is one on the VFD. You really just need single phase in and 3ph out to the motor.

Or you can add a remote one like he has shown. Depending on the feature set of your VFD, you can usually also add a braking resistor, a fwd/rev/stop switch, a jog switch, Etc. Etc

You can also program the VFD for minimum frequency, max frequency, accel and decel rate, etc etc.

So a VFD is more than just a way to run a 3ph motor at variable speeds on a single phase system. It can also be a very sophisticated motor control system.
 

thestelster

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If you are only going to have that one unit using 220v, then put a safety switch before the VFD. The Canadian Electrical Code wants you to have a motor disconnect within eye-sight of the motor.

If you plan on having multiple motors and electrical, you can put a breaker panel in the garage, and then wire all the garage electrical to that panel (not necessary, but handy).

This is how I set up my Tool &Cutter Grinder.

A 220v line comes from the house into the garage to a plug on the wall. I ran a line from that plug to the safety switch, then to the VFD, then to the motor. Very simple.
 

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Dusty

(Bill)
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uh... perhaps. I'm not sure what changes you have in mind. (perhaps I have missed it)


Yes, you use a normal 220V plug, wired to a VFD box, and you have 3PH electricity wired from that box directly to your motor.


Post a picture of your motor, and a picture of your motor plate. We can help you figure it out.

@Dabbler ,sorry for the delay in getting back to you.

Yes we are on the same track as far as wiring goes from my electrical box to the 220 V outlet in my garage.

Bolt pattern measurements 5" high X 5.5 " wide, unsure how this translates into a Frame number for a replacement motor. Help.....!!

Pictures as requested:
 

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Dabbler

ersatz engineer
Great chart. Looks like a 56H frame - IF it is a 5/8 shaft. 7/8 shaft, a 145T.

The frame size isn't a bid deal: As long as the shaft size is the same, an adapter plate can be made with a cordless drill and some bolts. Easy peasy!

Make a rubbing of your motor base, and when you go to look at a used motor, it will be easy to check if it is similar. To preserve the same belt length the base-to-centreline distance should be close.
 

6.5 Fan

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My emotorsdirect.ca order history doesn't show the motor I bought.
Jeez i went to emotors to look around, can't afford those prices, over a grand for a 2hp 3ph. Maybe im looking in the wrong spot. I bought a used 2hp 3ph off Kijiji, the wiring looks real sketchy, might have to drag it in and have a better look at it.
 

thestelster

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Susquatch

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Jeez i went to emotors to look around, can't afford those prices, over a grand for a 2hp 3ph. Maybe im looking in the wrong spot. I bought a used 2hp 3ph off Kijiji, the wiring looks real sketchy, might have to drag it in and have a better look at it.

They have 2hp 3ph motors for a third of that.


And "rarely" they have returns. You have to talk to them to get those.

I don't have my model handy, but it's a Nidec 2Hp inverter rated motor that had been returned (open box). I don't recall the price but I want to say around 250.

Edit - my motor is this one. Price has gone up (like everything).


Depending on what you want it for, I still recommend Kijiji. I just recently got a brand new take-off 2hp 1000-1 motor for $50 for another member. Patience is required if you go that route.
 
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combustable herbage

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Their knowledge base is very thorough I used it as a resource when I did my 220v switch on my lathe. Many good wiring diagrams to confirm my configuration.
 

Susquatch

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Just a few quick notes on inverter rated motors.

Inverter (VFD) rated motors have bearings, windings, and wiring designed to handle the stray currents associated with high frequency input power. (chopped input voltage)

Turndown ratio is the lowest speed the motor can handle at rated torque. So a 10:1 motor can run at 6Hz (1/10th of 60), a 20:1 can run at 3Hz, and a 1000:1 can deliver full torque at 0 RPM.

It helps to read the documentation for the motor you are interested in. It may have other notes about cooling and duty cycle.
 

historicalarms

Ultra Member
Interesting thread for me, I just salvaged a 5 hp 3phase off an old lathe (automated threading lathe) that has been sitting outside for 10 yrs or more. I dont know if it is any good as it sits but the shaft turns effortlessly and i can not detect any "burnt wiring" smell to the thing.
I thought it might be saleable but am learning here that value will be negligible.
This thing has a centrifugal expanding belt drive system attached to it, I might not be describing it correctly but think snow machine variable speed drive system.
If anybody needs such a critter it's in central Ab just waiting to be picked up.
 
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