# Understanding vendor warning: phase converter



## visenfile (Apr 6, 2014)

Why would a vendor of a new 220 single phase machine warn of void warranty if "static phase converter" is used? (noob here)


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## Cobra (Apr 6, 2014)

If it is a single phase 220V, what would you need with a phase converter?


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## John Hasler (Apr 6, 2014)

visenfile said:


> Why would a vendor of a new 220 single phase machine warn of void warranty if "static phase converter" is used? (noob here)



Perhaps they sell the same machine with both single-phase and three-phase motors and attach the same set of boiler-plate warnings to both.


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## Ray C (Apr 6, 2014)

Or maybe they dislike static converters just as much as I do :rofl:.


Ray


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## Walsheng (Apr 6, 2014)

Ray:  What don't you like about them?

John


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## Ray C (Apr 6, 2014)

Walsheng said:


> Ray:  What don't you like about them?
> 
> John



They tend to burn-up motors because they produce very dirty, unbalanced power.  Also, at best they're about 60% efficient.


Ray


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## John Hasler (Apr 6, 2014)

Ray C said:


> They tend to burn-up motors because they produce very dirty, unbalanced power.  Also, at best they're about 60% efficient.
> 
> 
> Ray



Mine works fine (perhaps because I designed and built it with a full understanding of the limitations).  A static converter converts the motor, not the power.  It must be optimzed for a specific motor.  A three-phase motor running on single-phase via a static converter is nearly as efficient as it would be on three-phase but it is only capable of delivering a bit more than half its rated power.


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## Cobra (Apr 6, 2014)

Even the new VFDs Ray?  The controls guys I was working with have a high opinion of the new AB and  GE equipment.  I was looking at this route to get away from burned capacitors on the lathe from the jog button. 
Jim


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## Ray C (Apr 6, 2014)

Cobra said:


> Even the new VFDs Ray?  The controls guys I was working with have a high opinion of the new AB and  GE equipment.  I was looking at this route to get away from burned capacitors on the lathe from the jog button.
> Jim



 VFDs do a good job of producing well balanced and evenly spaced phases.  Older motors should be used carefully with VFDs especially if you plan to spin them at low speeds.  The old motors relied on full RPMs to spin fast enough to self cool.  

I couldn't even guess the number of people who've reported cooked motors after using a static converter.  The power from a typical static converter runs the machine with poorly balanced phases.  Most modern electronics such as DROs will see the irregular input signal and not power-up.  This is similar to running home electronics off a cheap gas generator where the frequency varies a lot.  Many modern intelligent power supplies say "heck no, something is wrong" and don't power up.


Ray


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## John Hasler (Apr 6, 2014)

Cobra said:


> Even the new VFDs Ray?  The controls guys I was working with have a high opinion of the new AB and  GE equipment.  I was looking at this route to get away from burned capacitors on the lathe from the jog button.
> Jim



A VFD is an entirely different thing from a static converter.  A VFD actually generates true three-phase power.  A "static converter" is a network of capacitors and relays that converts a three-phase motor into a capacitor-start capacitor-run single-phase motor.  It does not, in and of itself, produce three-phase power (though it can be a component of a rotary converter).  If you treat a static converter as a black box that takes single-phase power in one side and puts three-phase power out the other you will get into trouble. 

BTW jogging is very hard on motors and controls.


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## Cobra (Apr 6, 2014)

John Hasler said:


> A VFD is an entirely different thing from a static converter.  A VFD actually generates true three-phase power.  A "static converter" is a network of capacitors and relays that converts a three-phase motor into a capacitor-start capacitor-run single-phase motor.  It does not, in and of itself, produce three-phase power (though it can be a component of a rotary converter).  If you treat a static converter as a black box that takes single-phase power in one side and puts three-phase power out the other you will get into trouble.
> 
> BTW jogging is very hard on motors and controls.



Hence my comment. I burned up two starter capacitors before I twigged to the idea that I was the problem using the jog button while threading. 
Live and learn!

jim


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## AlanR (Apr 6, 2014)

Cobra said:


> Hence my comment. I burned up two starter capacitors before I twigged to the idea that I was the problem using the jog button while threading.
> Live and learn!
> 
> jim



Switch to a three phase motor and a VFD and you can jog to your heart's content. The jog speed should be adjustable on the VFD.


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## Ray C (Apr 6, 2014)

AlanR said:


> Switch to a three phase motor and a VFD and you can jog to your heart's content. The jog speed should be adjustable on the VFD.



Yes, and if anyone knows how to read the hieroglyphics of the HuangYang VFD regarding the jog function, please let me know.  I keep meaning to vow to decipher the manual but, I get a headache just thinking about it.

Ray


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## AlanR (Apr 6, 2014)

Ray C said:


> Yes, and if anyone knows how to read the hieroglyphics of the HuangYang VFD regarding the jog function, please let me know.  I keep meaning to vow to decipher the manual but, I get a headache just thinking about it.
> 
> Ray


What do you want to know?


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## Ray C (Apr 6, 2014)

AlanR said:


> What do you want to know?



It's mainly laziness on my part but, I never connected the jog button when I converted my PM1236 to 3 phase.  All other switches and safeties work fine.  As I recall, I made jog connections but could not get it to jog in forward or reverse but rather, forward jog only.  I diddled with it for a short while and deemed it unimportant but, one of these days, I'd like to get it working properly.

Ray


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## visenfile (Apr 6, 2014)

Thanks,  I get the drift that on some lathes  do not trick them when they need 3 phase.  I did not get the vendor name, but the machine looked Chinese without a branding name plate.  So this subject should give pause before buying a lathe advertised 3 phase ,while the buyer has only single phase houshold service?  (I read the Wiki writeup on phase converters -3 types).


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## Ray C (Apr 6, 2014)

visenfile said:


> Thanks,  I get the drift that on some lathes  do not trick them when they need 3 phase.  I did not get the vendor name, but the machine looked Chinese without a branding name plate.  So this subject should give pause before buying a lathe advertised 3 phase ,while the buyer has only single phase houshold service?  (I read the Wiki writeup on phase converters -3 types).



I'd ask the seller if he used a VFD, Rotary Converter or Static Converter.  VFD and Rotary are preferable and less likely to overheat the motor provided they were properly sized and configured.


Ray


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## AlanR (Apr 6, 2014)

Ray C said:


> It's mainly laziness on my part but, I never connected the jog button when I converted my PM1236 to 3 phase.  All other switches and safeties work fine.  As I recall, I made jog connections but could not get it to jog in forward or reverse but rather, forward jog only.  I diddled with it for a short while and deemed it unimportant but, one of these days, I'd like to get it working properly.
> 
> Ray


This is my control panel. with the rocker switch pushed in at the top twist the lever switch to the left (ccw) to start and run normally, to the right (cw) the machine runs in reverse. The red button is of course, stop.

Flip the rocker switch down and then the lever switch will jog the machine forward or reverse depending on how you twist the switch, the stop button has no effect.

The speed potentiometer knob can be seen on the left. The photo is deceptive, the machine switch is 2 - 3 inches behind the speed control knob, I keep the knob off and only put it on to switch from 4 to 8 pole (high/low) when the VFD is not supplying power.




For jogging I set Pd 047 to 07 and Pd 048 to 08. the corresponding terminals are SPM and SPH.

The lever switch is deceptive, it's four switches ganged, two for run (forward and reverse) two for jog (forward and reverse). The rocker switch is DCM for the center terminal and it switches DCM to either the stop button OR to both jog switches.

Pd 020 sets jog acceleration
Pd 021 sets jog deceleration
Pd 042 sets jog frequency (speed)

Edit: I forgot to mention, all the switches are momentary contact except for the rocker switch. Stop is NC, all the others NO.


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## Ray C (Apr 6, 2014)

AlanR said:


> This is my control panel. with the rocker switch pushed in at the top twist the lever switch to the left (ccw) to start and run normally, to the right (cw) the machine runs in reverse. The red button is of course, stop.
> 
> Flip the rocker switch down and then the lever switch will jog the machine forward or reverse depending on how you twist the switch, the stop button has no effect.
> 
> ...



Much thanks!


Ray


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## John Hasler (Apr 6, 2014)

visenfile said:


> Thanks,  I get the drift that on some lathes  do not trick them when they need 3 phase.  I did not get the vendor name, but the machine looked Chinese without a branding name plate.  So this subject should give pause before buying a lathe advertised 3 phase ,while the buyer has only single phase houshold service?  (I read the Wiki writeup on phase converters -3 types).



If I was going to spend a few thousand on a machine I'd find a bit more for a VFD.  Static converters are for cheapskates like me.


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## Ray C (Apr 6, 2014)

John Hasler said:


> If I was going to spend a few thousand on a machine I'd find a bit more for a VFD.  Static converters are for cheapskates like me.



Not agreeing that John is a Cheapskate as he freely assists a lot of people here but, I fully agree that a few hundred bucks for a VFD is a reasonable investment for a piece of shop equipment.


Ray


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