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VFD for Cincinnati lathe with 3HP. Motor data plate pic attached.

JENIUS

Plastic
Joined
Jul 25, 2022
I have been combing the forum for a week or so and trying to get up to speed on VFD'S. I need an in-stock VFD for my 3 h.p. 15x54 Cincinnati tray-top. There are so many choices and vendors it will take me months to make an educated choice. Could someone please give me a direct recomendation? I have single phase 220 available. I have 20 amp, 30 amp and even 60 amp power near my lathe. I have attached a photo of the motor data plate. The lathe is fully mechanical, with only a drum switch actuated by the fwd/rev/neutral handles. It has a coolant pump on a separate on/off switch.
 

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I would use this one: Only $268 !!
Excellent support from both Marshall-Wolf and Fuji. Single phase supply rating of 9.7 amps. (19 amps with 3 phase supply).
Have confidence. Very easy to install. Wire your drum switch back to "FWD/CM/REV" terminals to control the VFD from your exiting switch.
Then wire the output of the VFD directly to your motor.
 
I believe that requires 3 phase input, i only have single phase.

I think this is is what i need. I heard you should over size them?

 
I believe that requires 3 phase input, i only have single phase.

I think this is is what i need. I heard you should over size them?

Over size by 2x only when greater then 3HP, as the input diodes are what limit operation from single phase power source. If you read the 3HP manual, you will see it can operate from single phase with no derating.
That's a pricey unit for 3HP.
Try this seller, and you can see their inventory count;

Hitachi;

TECO;
 
First, you need to learn to spell Cincinnati..........

My choice. Has a built braking resistor capability which I highly recommend. I have this on my lathe and love it.

 
I would use this one: Only $268 !!
Excellent support from both Marshall-Wolf and Fuji. Single phase supply rating of 9.7 amps. (19 amps with 3 phase supply).
Have confidence. Very easy to install. Wire your drum switch back to "FWD/CM/REV" terminals to control the VFD from your exiting switch.
Then wire the output of the VFD directly to your motor.
I like the idea about wiring it thru the drum switch, i was under the impression that the VFD needed to see a 0-20 signal for switching?
 
First, you need to learn to spell Cincinnati..........

My choice. Has a built braking resistor capability which I highly recommend. I have this on my lathe and love it.

I looked into the dynamic braking, looks like a worth while feature that i didnt know i needed. Does it require a speed sensor or any additional hardware? Or is it part of the programing/setup cabability of the unit?
 
I believe that requires 3 phase input, i only have single phase.

I think this is is what i need. I heard you should over size them?

Jenius,
This VFD is rated at 9 amps or so on Single phase supply and 19 amps on 3 phase, as I indicated in my response.

Have confidence, my friend, its very straight forward. and its only $268, in stock.

I'm not sure, but I believe many VFD's have a built in braking resistor. But there's a lot of energy in a chuck, plus all the gears spinning at speed. I'd be very surprised if an internal braking resistor is capable of absorbing that much energy.

I have an external resistor on my lathe, which can stop the chuck very quickly. They're not that expensive, and Fuji has them in various sizes, and Marshall-Wolfe can advise you on the best one. Easy to wire, and set up VFD.
Bob
 
I would not spend the extra money on an oversized 3 phase inpiut VFD, there are plenty of single phase input VFD's in the $300-400 range with good support and a US based warranty. I am only including suggestions for those that are showing in stock. Hitachi WJ200-022SF, WEG CFW300B10P0B2DB20, Fuji Electric FRN0012C2S-7U are all good VFD's with a wider range of programming and features, but can be a bit more intimidating to setup. Any of these will be way more than you need as far as features. You need to direct wire the output of the VFD to your motor, get rid of the drum switch. You can get a 3 way sustained switch and wire the inputs so you have Forward-Stop-Reverse, alternative is 3 wire control which uses momentary switches for the run/stop (some use a sustained for reverse other like the Invertek and Lenze use a monetary). On the braking resistor you do not need to get the factory resistor, there are lots of power resistors available for $50-60, usually for this size VFD something in the 50-75 ohm range, 300-500W, size should be listed in the manual or ask.
Teco Westinghouse L510-203-H1-U are reliable and easy to setup/configure. It has internal braking but does not support and external braking resistor (expected stopping is ~3 seconds)

Teco Westinghouse E510-203-H-U a bit more full featured and supports an external braking resistor

Invertek ODE-3-220105-1F42 are simple to setup and have good tech. support. If you want an external braking resistor for faster stopping, this unit supports it.
 
This is such a great forum. I really appreciate the input.

My drum switch is buried inside the machine cover, and i have no problem with bypassing it. I was anticipating on building a stand alone control panel to integrate a fwd/rev switch and a stop switch. After these conversations i was wondering if anyone swapped out the drum switch for a solid state type switch that would allow for using of the spindle engagement handles for actuating the VFD? I have attached a pic of my current barrel switch location for clarity. Upon reviewing the pic i noticed the drum switch rod also actuates an arm on the oil filter for some purpose. If i bypass the spindle engagement levers in favor of an external motor control switch, how do i account for the apparently necessary oil filter lever arm.

Sorry for the newby questions.
 
There will be wires from the drum switch back to the control panel, and probably to the contactor coils. There's probably a connector block where all these wires come together.
Find the 3 wires from your drum switch; disconnect (from the connector block), and label them; then connect new wires from here to the FWD/COM/REV terminals on your VFD.
This way you'll be using the original lathe controls to operate, as normal.
Very easy and straightforward with that Fuji VFD I recommended. Only $268.
don't over think it.
Bob
 
I do not think it has anything tying it to the electrical, only the fact that the spindle engagment handle that actuates the soon to be bypassed barrel switch also throws a little lever on the filter. Switching to a VFD and bypassing the barrel switch will result in that little lever never moving again unless i remember to do it.

This lathe has only been in my possession for 3 weeks, the filter will get pulled and cleaned/examimed/changed soon.
 
If this is a hydrashift lathe, then the motor is controlled separately from the engagement handle. The ones posted online have push buttons to run the motor/direction and then the spindle/feed/braking is controlled by the Hydrashift/mechanical handle. The linkage back to the filter/pump may be a bypass when the hydrualic drive is not engaged.

The invertec has simple setup macos like below that use three momentary switches, two NO for FWD/REV and a NC for STOP. If you have similar push buttons on the front panel it would be an easy substitution. If you want additional programing functions, then some of the other VFD's have more features/inputs, but the Invertek may also work well. With 3 wire control the lathe will always be in the stop mode when powered up. If you want an E-Stop you could put it in series with the NC STOP contatact, or in some cases there can be a separate emergency stop input. Since VFD's use low voltage/current inputs for commands, older switch that have pitted/burnt contacts do not conduct the signaling well. If y have the option to replace the mechanical switches, then that may work. I have used electronic switches for some applications, but this is not one that I recommend.

1659555629021.png
 
Not a hydra shift. The only switch on the lathe anywhere is the coolant pump on/off switch. I just ordered the teco westinghouse drive recommended above
Teco Westinghouse (L510-203-H1-U), from wolfautomation, and one of their switch panels.
 
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I have been combing the forum for a week or so and trying to get up to speed on VFD'S. I need an in-stock VFD for my 3 h.p. 15x54 Cincinnati tray-top. There are so many choices and vendors it will take me months to make an educated choice. Could someone please give me a direct recomendation? I have single phase 220 available. I have 20 amp, 30 amp and even 60 amp power near my lathe. I have attached a photo of the motor data plate. The lathe is fully mechanical, with only a drum switch actuated by the fwd/rev/neutral handles. It has a coolant pump on a separate on/off switch.

as for your needed single phase power
these few equations will help to guide you
1 HP =746 watts
watts = volts times amps
amps = watts divided by volts

none of this includes efficiency or other loss considerations that will eat a small percentage of your supply amps
it also does not include starting amps which will be much higher until the motor is up to speed
always go to a larger supply than the minimum calculated
total available amps well above the minimum is not a problem of any kind
 








 
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