# 120v To 240v Help Needed



## calstar (Mar 1, 2015)

See the attached pics for reference. The colors of the wires do not match the colors shown on the wiring diagram, hoping someone can help me out. I assume the forward/reverse switch also must be changed so please take a look at that as well.

thanks a lot, Brian




"With thermal protection",  didn't have it previously






as wired for 120v, wire colors do not match diagram so....?



switch in off position, pulling knob toward you in first pic below runs forward, loose ground wires attach with switch box mounting screws


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## Ulma Doctor (Mar 1, 2015)

if you disconnect the power cord from the motor and snap another picture, it will be easier  for me to see the motor taps and therefore easier to help out.


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## calstar (Mar 1, 2015)

Ulma Doctor said:


> if you disconnect the power cord from the motor and snap another picture, it will be easier  for me to see the motor taps and therefore easier to help out.



OK, here ya go, thanks. Green, yellow, blue, white, black and red from motor.  Brian


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## Ulma Doctor (Mar 1, 2015)

Hi Brian,
the blue wire is capped off.
the motor green and white wires are paired up and paired with the black switch wire.
the motor yellow, is paired up the red switch wire
motor red will go back to white switch wire
motor black will go back to switch brown.

whoever wired it up the first time reversed the black/red pairing and the white/yellow/black pairings respectively which would have the motor turning the opposing direction.


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## calstar (Mar 1, 2015)

Thanks so much _Ulma Doctor. _So I don't need to do anything in the switch box, its good to go as is?

Brian


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## Ulma Doctor (Mar 1, 2015)

Hey Brian,
if it ran before on 115v- you'll be good to go on 230v.
the 230v has the windings in series, in 115v the windings are wired parallel

i would ask if there are any transformers in the machine????
you'll need to re-tap them if you do!!!


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## calstar (Mar 1, 2015)

[QUOTE="Ulma Doctor, post: 279479, member: 22605"
...i would ask if there are any transformers in the machine????
you'll need to re-tap them if you do!!![/QUOTE]

Just the stock motor and switch, nothing else on the mill, so no transformers. Brian


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## Ulma Doctor (Mar 1, 2015)

Excellent!


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## calstar (Mar 2, 2015)

The mill did come with a thermal overload protection switch(see pics) but not installed. The motor does not have a "built in" overload protection reset button so since I have it I may as well install it but need guidance(again), how would I connect it? I'll be replacing the armored cable that hard wired the mill previously with a power cord, makes more sense, I have the mill on a mobile base. Seems like the overload switch would go between the drum switch and the plug on the power cord, but how do I wire the 240, one of the legs to the switch(in and out)?
I'd run the cord from the drum switch to a  box for the overload switch and then continue the cord with a plugged end, at least thats my thinking.

thanks, Brian

motor rewired for 240(may be overkill but I'm in the habit of wrapping the connectors) 






one of the legs connected to these terminals?



nothing on this side to connect


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## Ulma Doctor (Mar 2, 2015)

there should be 2 terminal lugs on the overload device.  you may see another lug if you take off the faceplate.
one power leg power will run through the device, it's contact can be broken by thermal deformation of a bimetallic heater located in the center of picture 1.
you could use the switch red or switch black on the overload device as either leg is 115v in reference to neutral, either wire would give the desired effect.


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## calstar (Mar 3, 2015)

*Damn that magic smoke!!*  Think I fried the motor(damn again). I turned the motor on expecting to here a pleasant humming, sounded like a cross between buzzing and  a grinding, hit the reverse position and the motor did reverse, turned it off, maybe  ran for 10 seconds, smelled hot and motor case was hot to the touch, not warm, hot.  Thought about this for a minute, removed belt from motor pulley to see if the noise might be  bearing but really doubted it. Turned motor on again, maybe 5 seconds and there it was, magic smoke #%*^+!!!

I'm bummed not because I'll probably need a new motor(I'm still extremely happy with lucking into the mill) but because I screwed up the oem motor, I'm kinda sentimental about old machinery.

So take a look and let me know what you think.  Live and learn, etc., etc., etc. On the plus side I was thinking of getting a DC motor sometime in the future for variable speed and better torque, looks like the future may be now!

Brian

As wired for 120, blue is the hot leg, white is neutral( before I rewired for 240 and before the magic started)



as I wired for 240, the white with the black tape at the bottom is one hot leg, the black hot leg replaced the white neutral, wasn't thinking when I did this(obviously), just replaced the wires where they were before, after the fact I see both hot legs are on the same side so is that the f#*k up?






Should the black leg have gone on this side somewhere(he asks belatedly)?


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## Ulma Doctor (Mar 3, 2015)

i think there may have been a miscommunication, or misunderstanding........
in post 4,
because i was looking at the last picture of post#3, 
the wire combinations i gave were intended to be made at the motor junction box only.
changing the other wires may have been bad.
Remove the motor and if so inclined, 
you could try to wire it back up to 115 and see if it runs again before buying another motor, as a suggestion.

3/4 hp- 56 frame- 1725 rpm- motors are plentiful, another motor will not bring the value down


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## calstar (Mar 3, 2015)

Ulma Doctor said:


> ...i think there may have been a miscommunication, or misunderstanding........



Its all good, just a another little hiccup in the day, not the first time I didn't fully understand something and moved ahead regardless. So, just for my understanding(and probably others, we're all here to learn, right?) where should the two hot legs have gone?

I will try wiring it back up to 120 and see if its not too fried to run on that voltage, can't hurt at this point. I have a few other motor options in my shop(including a shunt wound DC that came on my other more "experienced" 8530), I'll see what I can come up with. Not worried at all about the mills value, its a long term keeper!


thanks, Brian


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## calstar (Mar 4, 2015)

calstar said:


> ..*I will try wiring it back up to 120* and see if its not too fried to run on that voltage, can't hurt at this point.



*Yes indeed!!! * Rewired back to 120, it runs super smooth, quiet and cool. Vintage integrity restored, I like that. Not sure how that all works but for now I'm OK with my ignorance,  I'm not messing around with it any more, will use as is!!

Brian


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## mws (Mar 7, 2015)

At the risk of getting myself in trouble...

It appears that the BLUE motor wire is what the label shows as BROWN.  
So 
BLUE & WHITE are from one of the two 115v RUN windings
GREEN & YELLOW is the other 115v RUN winding
These must be paralleled for 120:  L1+BLUE+GREEN and L2+WHITE+YELLOW  120 volts across both windings.  
In series for 240: L1-BLUE,   WHITE-GREEN,  L2-YELLOW  240 divided between the series. 120 from BLUE to WHITE and 120 from GREEN to YELLOW, 240 total.  

RED and BLACK are the start winding. This winding MUST have 120 volts!! To get that from 240 you simply parallel ONE of the run windings.  Meaning one of the start winding connections must go to the junction of the 2 run windings, WHITE-GREEN, always.  The other start winding wire is free to be switched to either L1 or L2 as desired for FORWARD or REVERSE, since this also inverts the phase. Here's how I usually wire single phase, cap start motors.  I'm not exactly  sure how your drum switch works but it looks like it's the same.  Your wiring is similar given the blue jumper on your switch.  I've changed my drawing slightly to match your motor wire colors.  You'll note that since I pick up the motor center voltage IN the motor for the the start winding I only require three wires from the drum switch.  
Your thermal interrupt can go in either the M1, M2, L1 or l2 line as you like, where you like. I wouldn't bother however as if it's sized for 120 current the 220 current is only half that and it's not likely to provide any protection, plus it only opens one of the two hot feeds.  If you have a decently sized 220 breaker in your feed panel you should be all set.  



I hope you find this useful. 

Mark


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## calstar (Mar 8, 2015)

Thanks for the great info Mark! As time allows I'll try again with the 240.  Does the fact that the motor was hot and smoked for a matter of seconds mean I ruined one of the windings(if thats the correct terminology) or is it still possible that the motor will function on 240? I was wondering about the thermal protector's ability to work with two hot legs, so I see there is no benefit of using it with the 240; my  breaker on that circuit is a 20amp.

Brian


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## calstar (Mar 8, 2015)

mws said:


> At the risk of getting myself in trouble...
> 
> It appears that the BLUE motor wire is what the label shows as BROWN.
> So
> ...






Here's the same pic from above(as I wired for 240) to easier compare the the diagram/info; does this wiring look right? Doesn't look like the high voltage wiring below but I may not be seeing it correctly. thanks, Brian


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## mws (Mar 9, 2015)

calstar said:


> Here's the same pic from above(as I wired for 240) to easier compare the the diagram/info; does this wiring look right? Doesn't look like the high voltage wiring below but I may not be seeing it correctly. thanks, Brian


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## mws (Mar 9, 2015)

OK, after additional review I'm 99.9% confident in the information I first sent. But I'll clarify that in a point-to-point color list like Ulma Doctor posted earlier. I'll still recommend that you pick up the 110 volts for one side of the start winding in the motor junction rather than using a fourth wire from the switch box. To me that's just a safer way of doing things. It's impossible to put 240 on the start winding this way. Also, nothing should ever be connected to L1 or L2 when the switch is off.


To answer your question, “Did the motor get damaged?”; I can't definitively answer that. I can tell you this: As you re-wired it you had 240 across the start and ONE run winding. Technically the motor SHOULD have turned and run but likely it would NOT have been happy doing so. The fact that the motor remained locked perplexes me but then, I've never done that to a motor.  The RUN winding could probably tolerate 240 far longer than could the start winding. Bottom line: if you didn't release too much of the magic smoke inside the motor you should be fine. Be alert if the motor starts to run rough or hot. But most (excluding some Chinese junque) motors require a fair amount of overheating before suffering terminal damage and I think you'll be fine. Just an opinion.


Point to point wiring:

I'll refer to my diagram below for numerated drum switch wiring. Remember to assure all ground conductors are secure.
If motor runs backwards, swap Black for Red at the drum switch.


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## mws (Mar 9, 2015)

Sorry for any formatting issues. Saving tables and images has been less than fruitful for me today.


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## calstar (Mar 13, 2015)

mws said:


> ....The fact that the* motor remained locked perplexes me* but then, I've never done that to a motor.
> 
> 
> 
> ...



from my earlier post;
_.....maybe ran for 10 seconds, smelled hot and motor case was hot to the touch, not warm, hot. Thought about this for a minute, removed belt from motor pulley to see if the noise might be bearing but really doubted it. Turned motor on again, maybe 5 seconds and there it was, magic smoke
_
The run times noted above were controlled manually by me, the motor did not lock/stop by itself, I'm guessing thats good news. I'm really loaded up with a lot of work(and family tasks, etc) so no shop time fora few days, I'll carefully try rewire to 240 when I get the opportunity.  I eventually want the mill on 240(as measured by the power company)  as I ran a dedicated circuit for it and my lathe, the close by 120 circuit receptacle already has enough things on it, otherwise I'd keep it on that.

Brian


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## mws (Mar 13, 2015)

That makes more sense. I don't know why I got the impression it didn't spin at all, but that's exactly what I would expect with only one run winding and 240 across it and the start winding.  Let us know how things turn out.  I know about getting busy. Sometimes my shop doesn't see me for weeks, but it doesn't complain about my absence like some do when I am in the shop for weeks.  

Mark


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## mws (Mar 13, 2015)

Brian,
Here's something to take note of.  Hman's post in this thread, http://www.hobby-machinist.com/threads/is-there-a-single-phase-220v-rotary-reversing-switch.31826/   , shows the wiring similar to mine, only the drum switch works a little differently.  I noted I wasn't sure how your drum switch worked, (unfortunately, they're not all the same). So please make note of your drum switch function before following my advice. Given that your drum switch clearly had the jumper already on the 3-5 terminals I'm still confident my wiring should work.  Otherwise the wiring is essentially the same.  
Specifically, http://www.hobby-machinist.com/attachments/3schematic-gif.97124/
Thanks hman. 

Mark


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