Ice Cream maker- Suggestions for a single phase to three phase transformer

[Buck Parrish]

I'm looking for suggestions on a single phase to three phase transformer. This will be for a used ice cream machine. It has a 20 amp 3 phase cord on it. No paperwork with it.
Its likely between 5 -12 amps.
What would be the most common transformer to use?

 

[Besoeker3]

I'm looking for suggestions on a single phase to three phase transformer. This will be for a used ice cream machine. It has a 20 amp 3 phase cord on it. No paperwork with it.
Its likely between 5 -12 amps.
What would be the most common transformer to use?

Single phase to DC to three phase using a VFD.

 

[Dennis Alwon]

You need a phase converter

 

[Dennis Alwon]

Here you go

 

[ActionDave]

I'm looking for suggestions on a single phase to three phase transformer. This will be for a used ice cream machine. It has a 20 amp 3 phase cord on it. No paperwork with it.
Its likely between 5 -12 amps.
What would be the most common transformer to use?

First suggestion is to find out what it is you have. Cords on kitchen equipment could have been swapped to match what was an available power recpt and have no relation to what is being powered up inside.

Second if the machine really is three phase it's likely just the motor that requires it and swapping out the motor to single phase can be a better option than messing around with the complexities of a phase converter.

 

[synchro]

First suggestion is to find out what it is you have. Cords on kitchen equipment could have been swapped to match what was an available power recpt and have no relation to what is being powered up inside.

Second if the machine really is three phase it's likely just the motor that requires it and swapping out the motor to single phase can be a better option than messing around with the complexities of a phase converter.

I agree. And if the machine doesn't provide sufficient information externally, it would be worthwhile opening it up to check out the motor's nameplate or at least how it's wired.

 

[__dan]

I'm looking for suggestions on a single phase to three phase transformer. This will be for a used ice cream machine. It has a 20 amp 3 phase cord on it. No paperwork with it.
Its likely between 5 -12 amps.
What would be the most common transformer to use?

Great suggestions so far. Look at the nameplate and then get the manfacturer's wiring diagram for the unit. I would guess that the unit is mostly a single phase load, but it could have a remote compressor refrigeration unit, and the compressor for that could be three phase (but check it).

I wired something like that, might have been ice cream with a remote rooftop compressor unit. They were all set to feed it three phase, but I looked at it before making the finish connection, and saw it was a H, H, N, G load, 208 V single phase, and the three pole breaker they gave me for it would have smoked the unit.

They may have saved money upfront on the used unit, but if it does require a three phase conversion of some type, the unforseen extra cost could be negating any of their savings. A rotary phase converter will have a lot of standby idle losses, and a control to turn the converter on and off with the load is just more unplanned unforseen cost.

If it does need three phase (check that manufacturer's wiring diagram), the cost of converting could be uneconomic.

 

[hillbilly1]

Rotary loss isn’t too bad, the one I’m putting in says 1 amp, but the manufacturer of the rotophase converter say to size it 50% higher than what is needed. Say, a 10 hp motor needs a 15 hp converter.

 

[zbang]

Should have mentioned earlier- I've met some ice cream machines are are extremely voltage sensitive. As in, 203v was too low on the 208v machine setting (which, I think, only affected the control system), and 215 was too high for the 208 but of course way to low for the 240v setting.

 

[__dan]

Rotary loss isn’t too bad, the one I’m putting in says 1 amp, but the manufacturer of the rotophase converter say to size it 50% higher than what is needed. Say, a 10 hp motor needs a 15 hp converter.

Running rotary loss is OK when the load is on. I was thinking of the loss if the converter is always on during the load's off time.

I put one on a commercial washer (donated to wash firefighter gear). I put it on a wall switch with two contactors, line side, and an on delayed load side contactor, with instructions to turn it off when they don't need the washer.

 

[Jraef]

To directly answer your question as asked, you can't get a "transformer" that creates 3 phase from a single phase source.* You need a "phase converter" of some sort. Any phase converter is going to be 1) expensive, 2) complex and/or difficult to implement and 3) will add losses to your system, meaning it will cost more to operate the machine every day. As a result, on something that has to be run on demand like an ice cream machine, you will likely be better off replacing the motor with a single phase version.

_{*OK, that's not ENTIRELY true, but the "transformer phase conversion" methods you might find if you dig deep into the bowels of the internet archives are wildly more complicated than the average electrician can deal with, or not REALLY giving you true 3 phase power (the "Scott T" transformer methodology).}

 

[jim dungar]

_{*OK, that's not ENTIRELY true, but the "transformer phase conversion" methods you might find if you dig deep into the bowels of the internet archives are wildly more complicated than the average electrician can deal with, or not REALLY giving you true 3 phase power (the "Scott T" transformer methodology).}

I agree.
As a side note, the Scott T connection is for going between 2 phase (90 degree phase shift) and 3 phase.
There is a strange 3 phase to 1 phase connection, but is not balanced and cannot go the other way.

 

[synchro]

If the power source is 120/208V 3-wire and not true single phase, then the third phase can be created from the other two with two single phase transformers.

 

[hillbilly1]

Tr

If the power source is 120/208V 3-wire and not true single phase, then the third phase can be created from the other two with two single phase transformers.

True, with an open delta, but I don’t think the op said if it was 120/208, or 120/240? We are assuming it is 120/240 single phase.

 

[jim dungar]

If the power source is 120/208V 3-wire and not true single phase, then the third phase can be created from the other two with two single phase transformers.

Then the system is actually 3 phase even though the specific circuit is single phase. I have heard some people call this an open wye, but that is not a common term.

 

[brantmacga]

For a load that small you might could get by with a static phase converter.


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[Buck Parrish]

Thanks. It is presently 120 / 240

 

[__dan]

_{*OK, that's not ENTIRELY true, but the "transformer phase conversion" methods you might find if you dig deep into the bowels of the internet archives are wildly more complicated than the average electrician can deal with, or not REALLY giving you true 3 phase power (the "Scott T" transformer methodology).}

Yep the one I put on the washer was recommended by the washer manufacturer as they had experience with it (I called around first to get some opinion). I got the best one I could.

So two legs come from the utility and one leg comes from the rotary converter. Converter manufacturer sized the unit, they called it a rotating transformer (and told me not to bolt it to anything as the vibration or shaking would not like it). I hung it from threaded rod on spring isolators, that did work.

The one leg out of the transformer had high voltage and the washer made a singing sound for the seconds that I tried that. Then I tried it again with the Fluke 87 in hand and measured exactly how much it was off, table values.

By the end of the next day or the day after, I had the Voltage trimmed down perfectly by using the winding of a small autotransformer (from my basement collection). I grabbed the one leg to one utility and subtracted the probably 12 volts. I had the option of either utility leg and tried both, the first hookup gave the best result. Machine ran perfectly quiet, no motor noise. Pretty sure that connection is non standard and likely still working I would say, from about 1995.

For the volunteer FD, I brought up the utility circuit to a small panelboard for future loads, but the panel was three phase and I marked it up as a red leg delta so they could add circuits to it.

 

[rambojoe]

The answer is, chocolate. Plain chocolate.

 

[augie47]

I'm sure there are many on here that can relate..... I can't count the number of times over the years that I have dealt with folks.. especially restaurant people.. whose approach to equipment is "it just plugs in" with no concept of single vs three phase, 208 vs 240, etc.
When faced with the economics involved, many swap or return the original equipment.