Phase converter question

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jdtm said:
That is NOT a motor nameplate! Whoever saw a motor nameplate with a "LARGEST MOTOR" rating?? Also a MODEL 92 motor would be a bit unlikely. What you got appears to be from the mixer itself so the installed motor is compatible with the rest of the electrical and mechanical parts of the mixer. TYPE 2P/4P almost certainly is 2 or 4 poles so the motor will have a synchronous speed of either 1800 RPM or 3600 RPM at 60 Hz.
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That is a picture of the phase converter.
 
jdtm said:
That is NOT a motor nameplate! Whoever saw a motor nameplate with a "LARGEST MOTOR" rating?? Also a MODEL 92 motor would be a bit unlikely. What you got appears to be from the mixer itself so the installed motor is compatible with the rest of the electrical and mechanical parts of the mixer. TYPE 2P/4P almost certainly is 2 or 4 poles so the motor will have a synchronous speed of either 1800 RPM or 3600 RPM at 60 Hz.
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Bad guess. It was bothering me that a mixer manufacturer would allow a factor of two variation in the speed. Google convinced me that Ronk makes phase converters, and they have a model 92. However their model 92 is rated for up to a 30 HP motor. Looking closer, that looks to be a model 82, which must be old since the internet does not know about it. It still seems reasonable that TYPE 2P/4P refers to 2 or 4 poles.
 
Watch, we'll probably find out this mixer is only a couple HP with some non-proprietary standard motor that can be bought off the shelf as single phase, And the installer installed a phase converter for "reasons"

And the rotary converter should have been a TEFC unit in a kitchen, but I doubt it is. My experience with restaurant owners is they like hacks
 
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"ROTO-CON® Rotary Phase Converter Standard ... Type P comes in 240V input/output (Type 2P) and 480V input/output. (Type 4P)"
ronkelectrical.com

ROTO-CON® Rotary Phase Converter Standard Type P

ROTO-CON® rotary converter provides smooth, reliable 3-phase power from single-phase lines. Best suited for operating motors that do not operate continuously at high load levels and for non-motor loads.
ronkelectrical.com ronkelectrical.com

Joethemechanic said:
I'm not seeing a restaurant with small single phase service and equipment most likely controlled by magnetic contactors as being concerned with harmonics. ...
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Indeed. The majority of the load is likely to be heating elements and air-conditioning & refrigeration compressors. Whatever non-linear load exists (and the harmonic content it generates) is likely to be too small to matter.

I have frequently seen a small separate branch panel dedicated to electronic gadgets, but I have never seen them fed with any sort of powerline conditioning. And only in larger installations with three-phase power.

ActionDave said:
... It's not a big deal to take the end bells off the phase converter. I bet it's packed full of flour.
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Flour + moisture + heat yields matzo. (an abrasive, low-strength ceramic material)
Add a little bit of old lubricant (varnish) and it'll become water resistant.
 
jdtm said:
Ronk makes phase converters, and they have a model 92. However their model 92 is rated for up to a 30 HP motor. Looking closer, that looks to be a model 82, which must be old since the internet does not know about it.
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Model 92 seems to be a catcall for an entire family of rotary converters.

Here at https://www.ebay.com/itm/186007480088 it is shown with a 30 HP max motor rating.
At https://www.ebay.com/itm/256101619840 it has a 2 HP max motor rating.
And at https://www.ebay.com/itm/374733432109 the rating drops to only 1 HP.

Given that "model 92" is so popular when it comes to Ronk rotary converters, this one too may be a model 92.
LarryFine said:
Add a little bit of cream cheese and it'll become delicious. 🥯
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You may have to look elsewhere for this delicacy since Ronk makes both TEFC and ODP versions. (See https://apelectric.com/content/PDF/Ronk/Rotocon CP Spec Sheet.pdf) It would not surprise me if both styles are model 92.
 
sw_ross said:
Would the auto-transformer be used to make voltage adjustments to the derived phase only?
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I did that once. I put in a rotary phase converter for a donated three phase washer for the local firehouse. I oversized it and the washer made a singing sound on the first try. The generated leg Voltage was high.

I used a small autotransformer from my basement collection and trimmed the generated leg, probably by the 12 Volts from one winding of the autotransformer. That could have been 30 years ago. I am guessing it's still running. Checked out beautiful and never heard a word about it since.
 
Joethemechanic said:
Watch, we'll probably find out this mixer is only a couple HP with some non-proprietary standard motor that can be bought off the shelf as single phase, And the installer installed a phase converter for "reasons"

And the rotary converter should have been a TEFC unit in a kitchen, but I doubt it is. My experience with restaurant owners is they like hacks
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In some big commercial mixers, the motor is custom and/or integrated to the housing and gear assembly, so changing it out is not an option.

No argument on the rest of it though. Some of the stuff I have seen in restaurants rivals farmers for the makeshift nature of it.
 
Joethemechanic said:
Watch, we'll probably find out this mixer is only a couple HP with some non-proprietary standard motor that can be bought off the shelf as single phase, And the installer installed a phase converter for "reasons"

And the rotary converter should have been a TEFC unit in a kitchen, but I doubt it is. My experience with restaurant owners is they like hacks
Click to expand...
I once needed a switched-reluctance motor for a project and found that a Hobart mixer had just the one that was needed. Mixer manufacturers can be creative both mechanically and electrically with their motors.

I think we all know someone who would prefer to use a hack to get something done even if it would be easier to do things the right way. Just try not to see that person when you look in the mirror!
 
My point was not to disparage farming as a profession, God knows we meet farmers. But we all know they are often finding themselves in situations, with regard to electrical equipment, where they chose to take shortcuts that WE know are dangerous and short sighted. I can’t count the number of pieces of pipe and bolts put in place of fuses, almost all of them in farms.
 
Jraef said:
My point was not to disparage farming as a profession, God knows we meet farmers. But we all know they are often finding themselves in situations, with regard to electrical equipment, where they chose to take shortcuts that WE know are dangerous and short sighted. I can’t count the number of pieces of pipe and bolts put in place of fuses, almost all of them in farms.
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Small chance of a fire vs a known loss of a year's worth of growing if this equipment does not operate now: I think a lot of times the farmers make a reasonable calculated risk based on their understanding of the risks and benefits. The problem is that the thinking is then that the electrical hazard is not really all that dangerous because nothing happened this time or other things come up and it is forgotten.
 
sw_ross said:
I have a local restaurant that has a 3P dough mixer, the building is single phase, so they have a phase converter just for this machine.

I think it’s a rotary phase converter but I haven’t seen it yet, I’m going to look at it tomorrow.

Problem is that the kitchen staff turns on the converter to operate mixer but when they’re done they forget to turn off the converter so it continues to run, sometimes for days (apparently).
The maintenance guy thinks the converter is not operating like it normally should and Thinks that it’s because the thing is left on. He says the outer case gets hot enough to burn skin if touched.

I’m trying to think if there’s a way to have the converter automatically shut down when not being used. It obviously can’t shut down while being used or the dough will be ruined.

Can anyone offer any suggestions about doing this?
Thanks
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Time to re-wire the whole distribution system, all over the country, and get rid of single-phase distribution. I know it won't happen -but I truly think that most of the power quality problems would be solved.
 
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