Wiring question (Help please!!!)

[Rick Christopherson]

4) Understood that a VFD costs me 15% (.85 x 1 HP= .85 HP)

I didn't follow all of the details in your posting, but this aspect struck me because it is not correct. Whoever told you that a VFD driven motor does not provide full power from the motor was mistaken. Since you have already purchased a single-phase motor don't change anything, but I suggest you also keep the 3-phase motor for future possibilities. A lathe is a perfect situation for wanting a 3-phase motor driven from a VFD, and this is not an option when you only have a single-phase motor. All I am saying is keep your options open for the future. I would have kept the 3-phase motor, myself.

Can anyone tell me what I would have to do to make this reversible? Is it worth it?

Oh, I didn't see this question until after I posted. If you want reversible, then put the 3-phase motor back in and use the VFD. You not only get variable speed control, but the motor will be reversible with a touch of a button.

[Rollie Meyers]

I didn't follow all of the details in your posting, but this aspect struck me because it is not correct. Whoever told you that a VFD driven motor does not provide full power from the motor was mistaken. Since you have already purchased a single-phase motor don't change anything, but I suggest you also keep the 3-phase motor for future possibilities. A lathe is a perfect situation for wanting a 3-phase motor driven from a VFD, and this is not an option when you only have a single-phase motor. All I am saying is keep your options open for the future. I would have kept the 3-phase motor, myself.Oh, I didn't see this question until after I posted. If you want reversible, then put the 3-phase motor back in and use the VFD. You not only get variable speed control, but the motor will be reversible with a touch of a button.

I agree w/ this also, but since you had the 1Ø motor it sort of became moot but a VFD is avail. for your 3Ø motor w/ 120 volt input & 240 volt 3Ø output see this link. http://www.factorymation.com/s.nl/it....f?category=30

[Dan Cobian]

I agree w/ this also, but since you had the 1Ø motor it sort of became moot but a VFD is avail. for your 3Ø motor w/ 120 volt input & 240 volt 3Ø output see this link. http://www.factorymation.com/s.nl/it....f?category=30

Thanks again everyone. Any logic at all to replacing the older (potentially 30 years old) 1 HP motor with a new 1.5 HP motor? If the concensus is (as it appears to be) that I would be better off using the existing motor, am I stuck with a new motor? I'd have to drive all the down to Richmond again (90 miles) to return the new motor. Can I sell the new WEG motor I got? Is it worth it

[Rollie Meyers]

Thanks again everyone. Any logic at all to replacing the older (potentially 30 years old) 1 HP motor with a new 1.5 HP motor? If the concensus is (as it appears to be) that I would be better off using the existing motor, am I stuck with a new motor? I'd have to drive all the down to Richmond again (90 miles) to return the new motor. Can I sell the new WEG motor I got? Is it worth it

Your older motor is prob a better motor then your new one (today's society is a throw-away one) when your lathe was built things were still built to last, jumping to 1½ from a 1 hp is not always the best,you could have too much horse power which could be a subject all by itself.....

[Dan Cobian]

Got it Rollie. I was hoping to maximize the heft of the new lathe with a a bigger motor. Next question (sorry for having so many), I looked at the switch- its a Cutler Hammer Magnetic switch (max load 600 Volts) any reason I can't just use the existing switch and use 110 v vs the 220v that it was origianlly wired for (there is no mention of amperage on the switch). I'll post a picture shortly

[Dan Cobian]

Rollie to me (the definitive untrained eye) it appears that I can wire this for 110 using the same color code? Black either side of switch and white to other side (tapped off from motor connection)?

DSC08010.jpg

DSC08011.jpg

[Chip Lindley]

IF the Cutler-Hammer On-Off switch is momentary type, it only engages or disengages the coil of the 3ph contactor. The coil voltage cannot be changed. (probably 220v) This renders your built-in motor starter unusable for 110v house current.
IF the switch *clicks* on/off, it could be used to start a motor, up the rated capacity of the switch at 110v. Capacity should be printed on the switch.

BUT, since a very economical VFD is available for 110v input/ 220v, 3ph-1hp output. I would GO FOR IT! Everything remains the same internally with your lathe. Return the *2-speed Fan Duty* motor and bite the bullet on the mileage. Chalk it up as a learning experience. the VFD will require no electrical surgery on your lathe, as adding the 110v motor and new switch will.

Your 30 year old 3ph 1hp motor is probably as powerful as any 1.5hp motor in woodworking machinery today. It is not and never will be *worn out* unless used to the point that bearings need replacement.

It's Your Money, Your Time, just My Suggestion! Happy New Year!!

[Dan Cobian]

http://www.sawmillcreek.org/showthread.php?t=99974

[Bill Brady]

Even if you use the 3-phase motor you will need to make sure it is connected for 220 volt not 440 volt, the connections are on the nameplate. There should be a control transformer that will need reconnected to 220 volt if the motor was ran on 440 volt. If it was ran on 440 volt the heaters on the contactor will be to small. If you use the VFD it may not work on the control transformer. The micro switch you showed the picture of probably is operated by a lever on the carriage and it enguages the headstock drive. Converting to single phase would be very involved aslo but the VFD may not work all the controls so there may not be any choice.

[Dan Cobian]

Thanks Bill. Looks like I'll be bypassing the start switch that's on the lathe.

[Rollie Meyers]

You don't want anything between the drive and the motor the existing controls need to be bypassed as the VFD will be providing your overload protection.The reason no switches or the like is the drive does not like external switching & you will run the risk of "letting the magic smoke out" let the drive do the switching. If you wanted only to have start/stop functions the existing push buttons could have been reused but since reversing is desirable you will need to provide another one or buy one w/ one mounted on the VFD I used this model it was $$$ but it will do almost all what was desired except wanted 120 volt input & had to settle for 240V.

http://dealerselectric.com/item.asp?...ID=28&scID=165

[Alan Schaffter]

Dan, I don't want to put a wrinkle in your revised plan, but some things you should know if you plan to go the VFD route. A VFD is not an end all, be all. That is why you don't see just VFD's on WW machinery- most with VFD's still retain some mechanical speed range changing capacity (see #3 below).

1. Do not put a switch (motor switch) between the VFD and the motor- you can fry the VFD with too much reverse current if you inadvertantly cycle the switch. Control the motor power with the VFD. Any switch or magnetic contactor should be connected before the VFD that is used to power up and power down the unit initially, not control the motor.

2. If you run a VFD designed for dual 120/240 1/3 ph input (like many of the smaller VFDs) on 120V single phase, you may need to de-rate the capacity of the VFD i.e. A VFD rated for 1.5 hp on 220V, 3 phase input may need to be derated to 1 hp when run on 120V, single phase input. (That is the VFD rating, not the motor rating).

3. While VFD's can give you almost infinitely variable RPM, they lose torque at low RPM, so may not be suitable for a situation like turning large, heavy bowls. For that reason I put bigger, larger hp motors on both my VFD installations.

4. Standard rated induction motors work fine with VFDs, but if run under stress, at low RPM, can overheat quickly. Optimally, a VFD should be combined with an "inverter duty" motor which has better cooling and higher temp rated insulation. This is a function of the magnetic properties of the iron in the motor when run on anything other than 60 Hz..

All that being said, I put VFD's and standard 3 ph motors on my drill press and Delta lathe. I also added a tach to each. Most VFD's display output frequency which you can manually convert to RPM. Some allow you to program* in your pulley ratios and will give you a "computed" RPM. I chose to use a separate tach.

* Most VFD's have many, many parameters which you can/should program- ramp up/down time, max/min. freq. etc., etc. so don't buy a VFD w/o a manual!

Here is the speed knob and little toggle switch (run/stop) that control the motor and the tach readout I added to the front panel of my DP. The rather large VFD is mounted in back below the motor. Most VFD's allow remote control of the main functions (start/stop, fwd/rev, etc.) via low voltage wiring. I kept the original start stop buttons which power up the VFD.





Here is the lathe installation. I control the lathe directly using the VFD buttons and speed pot:

[Dan Cobian]

Alan,

Thank you for the feedback! If I understand it correctly, I will still have the mechanical speed change as well- so I can minimize the low torque by mechanically changing the speed as well? Also, I really like the lathe controls you have set up and was hoping to do the same with mine. What I envisioned was controlling the speed (and rev/fwd) from the VFD itself (mounted on the lathe)- would I still need a remote? I'm most likely going to get the http://www.factorymation.com/s.nl/it....f?category=30

Any thoughts?

[Dan Cobian]

Also, where did you get the RPM indicator?

[Alan Schaffter]

That VFD should work fine. Do note what they say about dust. I haven't had a problem so far with mine, and it is not in a NEMA 4 enclosure either. Also, be VERY CAREFUL wiring the unit, so you don't damage it or kill yourself with the high output- it has some big capacitors in it that carry a big whallop. There are numerous cautions throughout the manual- follow them closely!

You don't need any remotes. I needed them on the DP because of limited space and where I mounted the VFD, but I just use the keypad and convenient speed control knob on the lathe VFD. I prefer a speed knob over the up/down keypad buttons, but that is a personal choice.

I got the digital tach from MKC Tools. I mounted the lathe tach in a little homemade box but I had to rework the display a little so it would be on the edge of the circuit board for a low profile. With the DP I asked him to send me a unit with the display unmounted so I could put the readout on front of the DP and the circuit board up with the sensor in the pulley housing.