help with wiring plug for mini lathe

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Old 09-06-20, 12:35 PM
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help with wiring plug for mini lathe

Hi guys. Thanks in advance for looking at my post.
Forgive me if I am a bit too "wordy", but I want to give as much information as I can.

I recently was gifted a really nice mini lathe for woodworking. The person who gifted it to me told me that it was 110v, but the plug in has a different configuration than the "normal" 110v plug in. It is similar in size, but the prongs are horizontal, in line with each other rather than parallel to each other (I see that it might be called a "straight blade" plug). I attempted to do some research, and it seems that that plug configuration works with a 20 amp circuit...which I have installed in my garage, but I ALSO see that it can be rated at 250v ...which is confusing me.
The lathe was made by a Canadian company called One Way. I have the manual, and it says that that particular model was either shipped without a motor, with a 1/2 hp motor, or with a 1 hp motor. The 1/2 hp motor is 110v, the 1 hp motor is 220(240).
I had to pull the motor to get to the spec plate, and it told me that the motor was 208/220/240 (something like that...I may not have that exactly right).
So this seems simple, right...but here is the confusing part for me. The plug, and an aftermarket extension cord are both wired with 14/3 wire (it says so on the jacket). I took off the ends to see and they are wired with only hot, neutral and ground (black, white, green).
Am I safe assuming that this is a 110v connection with a different than normal plug end (probably to ensure that it is used on a 20 amp circuit instead of 15)? If that is true, the motor must have been wired for 110v instead of 220v. How can I tell? What else do I need to do to confirm this if this is not the case?
I'm not real bright, but I would sure like to avoid doing something that is going to prove it.

Please feel free to offer input or questions.

I just thought of something else... the motor is controlled by a speed controller. The plug that I was looking at powers the speed controller before it sends power to the motor.

Thanks!

 

Last edited by bullseyeguy; 09-06-20 at 01:35 PM. Reason: added photo

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09-06-20, 08:08 PM
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The pictures were a big help.

Wow..... that's an expensive piece. 120v in 240v 3 phase out.
Your power wiring will connect to the white and black wires that I put the red box around.
The green wire will connect to the metal equipment chassis.

So you can run that motor on 120v and it needs to be on a 120v 20A circuit.
That's probably why a 20A plug was used.
 
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Old 09-06-20, 12:45 PM
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Welcome to the forums.

Am I safe assuming that this is a 110v connection with a different than normal plug end
Absolutely not.

it told me that the motor was 208/220/240
If 120v was not listed there..... then it is not a 120v capable motor. You MUST read the motor nameplate.
 
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Old 09-06-20, 03:18 PM
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Ahhhh.....you added a picture. Very good.

Now the bad news..... that is a 3 phase high voltage motor and cannot be used in a residence.
That should have had four wires on it. One for each phase plus ground.

I just re-read your opening post. You said speed controller.
Does that have a make and model number on it ?
It may be some type of voltage convertor.
 
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Old 09-06-20, 06:05 PM
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Hi Pete,

Thanks for the response. The box is actually not really labeled in any way...at least not on the outside. It's One Way's "patented" controller box. I did manage to find some info on it in the manual. I should have looked at this before…now I feel dumb. I noticed the 3p on the picture of the motor after I posted it. Sometimes it takes someone like you who knows what they are looking for to add insight (which is why I am here). I read the manual about a month ago, and did not process the part where it says that it is a 3 phase motor that is controlled with single phase AC in, 3 phase out (see pic of page in manual).

I have also included a picture of the page in the manual that has a schematic for the controller box.


Truth be known...You missed the part about the speed controller because I wrote that when i went back and edited the post and added the picture. My fault, not yours.

Can you tell me what to look for (based on this information) so that I can determine what voltage? Is it even possible to have 14/3 wire for a 220v plug in??

If this IS 220v, how do I wire my plug to configure to three conductors instead of 4?

Thanks!
Brad



 

Last edited by PJmax; 09-06-20 at 08:06 PM. Reason: resized/labeled picture
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Old 09-06-20, 08:08 PM
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The pictures were a big help.

Wow..... that's an expensive piece. 120v in 240v 3 phase out.
Your power wiring will connect to the white and black wires that I put the red box around.
The green wire will connect to the metal equipment chassis.

So you can run that motor on 120v and it needs to be on a 120v 20A circuit.
That's probably why a 20A plug was used.
 
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Old 09-06-20, 08:44 PM
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Pete, I can't thank you enough! Sorry I didn't provide the necessary information in the first place...made you work for it. I really appreciate you helping me with this!

If you are ever in Colorado, let me know.... I owe you dinner!


Brad
 
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Old 09-06-20, 08:50 PM
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You're welcome. As is typical.... I'm on the other side of the country.
 
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Old 09-07-20, 05:56 AM
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Wait a moment!

The in-line prong plug is a 240 volt plug.

A 20 amp 120 volt plug has the hot and neutral prongs in a T formation, the neutral as the stem of the T

A 240 volt only appliance may have a cord with black/white/green conductors. A 240 volt only branch circuit may have standard Romex with black,/white/bare conductors.

But I am still skeptical about this lathe so I would be hesitant to plug it into a 240 volt air conditioner receptacle. And I would dislike the idea of having to cut off the plug, wire a 120 volt plug onto the end of the cord, try it out on 120 volts, and if it does not work with full power and correctly, then put back a 240 volt plug.

First try to find either a horsepower rating (which implies the supply voltage) or a supply voltage rating somewhere on the lathe but not on its motor name plate.

Test the lathe by unhooking its power cord from the control box and substituting a cannibalized cheap extension cord or other spare cord from your scrap parts box for 120 volts. Run it for a few minutes without a piece of wood in the chuck and it shouldn't overload the 16 gauge cord nor trip the breaker. Flip the selector switch on the control box to neutral and see if that is really the fast speed which means it is really 240 volts (supply) in.

If you can, measure the voltages across the motor leads T2 to T3, etc. at different speed settings. Here, if you get 200 plus volts at any forward/revers or speed setting while testing with 120 volts then you can assume it needs 120 volts in. Throw the original cord into your parts box and purchase a 20 amp 120 volt replacement appliance cord.
 

Last edited by AllanJ; 09-07-20 at 06:30 AM.
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Old 09-07-20, 08:12 AM
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I agree with Allan J that that style plug is 220V. but only 15A.

You have a lathe with a VFD (variable frequency drive) that runs a 3 phase motor. The input to the drive will be single phase. The motor rating is not what you need to look at for wiring it to your shop. The motor you have is a 1HP per the picture and the manual says it has a 220V input when equiped with a 1HP motor. That is consistent with the style plug you have. You need a 6-15R receptacle (single or duplex) wired for 220V (or 240V) to mate to your existing plug. Its wired with 2 hots and a Ground. No neutral wire is needed.

Have fun wood turning. I just started also.

Tom
 
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Old 09-07-20, 11:08 AM
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I guess we need to see more of the instruction manual.
I was at the website but it was not clear in which supply voltage is required,
 
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Old 09-07-20, 11:15 AM
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more follow up...

Hi AllanJ / TJexplorer,

I understand most of what you wrote, but I am still a little confused about something. You wrote that I should swap out the power cord and test it with 120, and if that doesn't overload the breaker or the machine, and the machine seems to be turning at full revolution (I think the motor said 1750rpm), then I am supposed to use 240?

"Test the lathe by unhooking its power cord from the control box and substituting a cannibalized cheap extension cord or other spare cord from your scrap parts box for 120 volts. Run it for a few minutes without a piece of wood in the chuck and it shouldn't overload the 16 gauge cord nor trip the breaker. Flip the selector switch on the control box to neutral and see if that is really the fast speed which means it is really 240 volts (supply) in."

I have had an electrician out to my house to run two new 20 amp (110v) circuits, and a new 220v circuit out to my garage. One of my ideas would be to buy the inline style receptacle, and replace one of the receptacles on one of the new 110v feeds, and then I can try that. Interestingly, the male plug in from the lathe does NOT have a factory plug end. I could just as easily remove and replace that.
The access to the motor is buried underneath the chassis of the machine when it is assembled (with the drive belt hooked up, and the motor on the mount. It will only install in that orientation because of the mount to tension the drive belt). There would be no way for me to get to it, nor can I see it. Right now I have the motor off, and I suppose i could leave it off, and do some of these tests before reinstalling it. I would want to know specifically what I am supposed to test though....you said T2 to T3. etc. Is it that simple?

Somewhere one or both of you keyed in on my original confusion. The manual tells me that it should be 220, but other indications, like the supply power cord don't seem to be sufficient for 220, right?? Or is that just me not knowing enough?
The other thing that bothered me about this was that the cord had the DIY plug end on it...totally adding to my skepticism about the whole thing. I got this machine from my boss, who, unfortunately, is a very unreliable source for information. He told me it was 110v...and that may be true, but like I said in my original post, I don't want to do something stupid just because i "think" it is correct. It MAY have come that way from OneWay...remember that they are a Canadian company. I suspect that he (my boss) had someone install that plug end to make it work with US style plug receptacles...I don't know if we are consistent with Canada or not. (I suspect not.) He may have even done this himself...and it may not be correct.

What happens if I test it with 110v and it really needs 220v? Will I cause damage?


Thanks to all of you for your time invested in helping me. I really appreciate it.

Brad


Anxious to start turning nice pieces of wood into worthless scraps!!
 
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Old 09-07-20, 12:33 PM
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I would not use 110V to test. you need to determine the correct voltage. The readings at motor leads do not make any difference as the VFD is converting the power and the measured motor voltage will vary based on the speed setting.

Why do you think the power cord is not good? For your application it is the same 2 wire with ground as 110V.. 14 gauge is fine.

The manual page you posted says to use 220V when the lathe is equipped with a 1 HP motor which aggress with the plug that was on it. Now being a user applied plug that plug may have be an incorrect application. Some OneWay lathes do use 110V. Can you post the model # of the lathe? There also should be a power ID label on the lathe unless it is a olde. you can also check with Oneway as to what power options they may of had.

I find a bonfire a good way to dispose of your "test" work.

Tom
 
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Old 09-07-20, 01:33 PM
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Thanks Tom,

I don't necessarily think the power cord is not good, I just have doubts, and I am confused by what I have seen...probably because I am ignorant. The model of the machine is a 1018. According to the manual, these either came without a motor, with a 1/2 hp motor, or with the 1 hp motor. As I stated in a previous post, the manual says that the 1/2 hp requires 110v, the 1 hp requires 220. ...you can see this on one of the pictures I took of the lathe manual.
This should have been simple, right? Sometimes I tend to make things more complicated than they should be, but the lathe literature tells me 1 hp/220v, and my boss told me 110v....so I felt I needed to look into this more.

I have not seen anything on the lathe or lathe stand that would give me any information...but I will look again.

"For your application it is the same 2 wire with ground as 110V.. 14 gauge is fine."
My 220 box has 4 wires.....I am assuming two hot, (red/black), neutral (white) and ground (green). How would I wire this three conductor plug?


 
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Old 09-07-20, 02:07 PM
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No one is say the existing cord is no good. I suggested substituting a junk cord to avoid modifying the existing cord and plug in a trial and error wild goose chase to figure out the correct supply voltage.

If you determine that 240 volts supply is correct then you reconnect the original cord. to the control box as you started with.

We know the motor is 240 volts. The unknown is whether the supply voltage should be 120 that the control box in the lathe will convert to 240.

In practically all cases the same appliance co4rd and the same Romex or THWN etc. wiring in the branch circuit can be used for either 120 volts or 240 volts. (The difference is wire rated for 125 volts as opposed to 250 or 600 volts.)

If you are wiring up a 240 volt only receptacle (wall plug) to a 120/240 volt branch circuit then connect the two in line slots to red and black of the feed and connect the ground hole to green. The white of the feed would be capped off and curled up in the outlet box.

Because (I am told) that the existing power plug for your lathe is 15 amp, then if you are supposed to use that plug the receptacle must match and the branch circuit breakered at 15 amps.

On second thought, er, third thought I think that the lathe control box does not boost the voltage, only chops* it to be the equivalent of lower voltage for lower speeds. So the supply voltage would be 240 for the motor rated at 240 volts.

* Using solid state circuitry and more efficient that a rheostat or a variable autotransformer.
 

Last edited by AllanJ; 09-07-20 at 02:31 PM.
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Old 09-07-20, 04:03 PM
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I would use a NEMA 15-15 plug set on the motor cord.
The cord itself should have a green wire and no white wire.
This is all independent of what’s going into the VFD.
 
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Old 09-07-20, 04:34 PM
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We are beating this to death. The cord the OP has is 14-3 and is fine whether used on 120v or 240v.
We need to determine what the line voltage required is for this convertor.
This is not just a variable speed converter..... it's also a phase generator as this is connected to a three phase motor.
 
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Old 09-07-20, 04:44 PM
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Everything indicates it 220 except you boss saying its 110V. So have him measure his receptacle if he has a meter.

 
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Old 09-07-20, 08:58 PM
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Thanks TJ. That would be good, except that he sold that house and moved about a year ago.

I think you guys have given this a good run for the money, and I have learned quite a bit too. I think I am going to see if I can get ahold of OneWay tomorrow, and have them confirm the plug configuration and voltage.

I'll let you know what I find out.

This was the other piece of information that I needed:
"If you are wiring up a 240 volt only receptacle (wall plug) to a 120/240 volt branch circuit then connect the two in line slots to red and black of the feed and connect the ground hole to green. The white of the feed would be capped off and curled up in the outlet box."

I sincerely appreciate all of the help and input you guys have offered. Please feel free to let me know if you have any more thoughts about this. I originally thought my question was kind of naive, but it seems that this is a pretty complicated thing to determine without someone with your skill sets looking at it in person.

I have also attempted to "pay this forward" responding to another poster who had an issue that I thought I could help with. I like this forum, and I hope to stick around and offer my input whenever I feel qualified to do so.

Brad
 
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Old 09-08-20, 06:32 PM
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The verdict is in.

I called OneWay, and spoke to someone knowledgeable about my situation. He told me that OneWay used to ship that lathe (no longer manufactured) with that same inline plug rated at 15amps for 220v plugin. Since I have the 1 HP motor, it needs 220.

I appreciate all the help you guys have offered.

Brad
 
 

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