Replacing a 3 phase VFD with a single phase derated VFD

If it's a PM motor, the VFD that you use must be capable of controlling a PM motor and one of the difficulties with PMAC motors is that the drives must be specifically tested with the PM motor you want to run, because they are all different. Obviously the Yaskawa is, so were I you, I would simply use another Yaskawa drive of the same model, sized for the single phase input.

What accessories should be used with a derated single phase inverter, on bad power

Jraef, thank you for your kind reply.
I so appreciate the unbiased advice of using the same manufacture and series inverter as Atlas originally installed. I like this Atlas compressor because it is made in Belgium, as opposed to China or Italy. Anyway, I'm also considering a Kaeser SM13, but this is a fixed speed compressor so it will be a true retrofit instead of a replacement-retrofit. Do you think I could likewise use a Yaskawa drive for the Kaeser? I found someone at Kaeser who said it is possible.


I am just not 100% sure how to install inverter, because I want to eventually use it in the Philippines, with choppy quality power. Here is what I know so far, please critique:
1) use a derated drive for single phase input and 3 phase output
2) use an AC load reactor with the inverter
3) remove the factor-installed EMC filter and DC link choke from the Atlas compressor -or, in the case of the Kaeser compressor- opt out of using those on the installation
4) keep the frequency of the inverter low, not high so that the motor sounds quieter


MY REASONING FOR WANTING to RETROFIT with a YASKAWA VFD:
1) retrofitting with a 28 year MeanTimeBeforeFailure Yaskawa drive will cost the same as using a 12 year MTBF Phase Perfect converter.
2) Yaskawa capacitors last 12 years, while PhasePerfect't only last 3 years
3) Using Sullair 10-hp single phase compressor will end up costing more in the long-run, since its motor efficiency is 90% and the Atlas is 93.3%.
4) A VFD will abolish the loading/unloading thing, so no wasted energy or risk of moisture in the oil

MarkDeRosa said:

Jraef, thank you for your kind reply.
I so appreciate the unbiased advice of using the same manufacture and series inverter as Atlas originally installed. I like this Atlas compressor because it is made in Belgium, as opposed to China or Italy. Anyway, I'm also considering a Kaeser SM13, but this is a fixed speed compressor so it will be a true retrofit instead of a replacement-retrofit. Do you think I could likewise use a Yaskawa drive for the Kaeser? I found someone at Kaeser who said it is possible.


I am just not 100% sure how to install inverter, because I want to eventually use it in the Philippines, with choppy quality power. Here is what I know so far, please critique:
1) use a derated drive for single phase input and 3 phase output
2) use an AC load reactor with the inverter
3) remove the factor-installed EMC filter and DC link choke from the Atlas compressor -or, in the case of the Kaeser compressor- opt out of using those on the installation
4) keep the frequency of the inverter low, not high so that the motor sounds quieter


MY REASONING FOR WANTING to RETROFIT with a YASKAWA VFD:
1) retrofitting with a 28 year MeanTimeBeforeFailure Yaskawa drive will cost the same as using a 12 year MTBF Phase Perfect converter.
2) Yaskawa capacitors last 12 years, while PhasePerfect't only last 3 years
3) Using Sullair 10-hp single phase compressor will end up costing more in the long-run, since its motor efficiency is 90% and the Atlas is 93.3%.
4) A VFD will abolish the loading/unloading thing, so no wasted energy or risk of moisture in the oil

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I submit you are over-thinking this and should use the 90% efficient NO OTHER PLAYERS Sullair 1-Phase with neither of a Phase-Perfect (itself only 93% efficient, per their own manual), nor a very-well-engineered but ALSO less than 100% efficient (95% ?) Yaskawa.

KISS method.

One set of losses, AND NOT a stacked set of greater-yet losses, needless extra spend, want of programming, and FAR more hard-to-replace stuff to fail. Dumb-old motors do OK there. Electronics PCBs not in an air-conditioned Telco // Data center do NOT do so well.

It is a "challenging" climate and Biosphere. VERY!

Having worked in the Phillpines (ETPI and PLDT), I'd also submit that your equipment is at greater risk of "vanishing" than using too much power or reaching extreme age. Buying what you need from local sources, in-barrio as well as in-country can reduce that risk. It's a "tribal" environment. Auslander's goods are but free food.

But that's a different set of "War Stories".

Is Sullair Shoptek a reliable compressor?

thermite said:

I submit you are over-thinking this and should use the 90% efficient NO OTHER PLAYERS Sullair 1-Phase with neither of a Phase-Perfect (itself only 93% efficient, per their own manual), nor a very-well-engineered but ALSO less than 100% efficient (95% ?) Yaskawa.

KISS method.

One set of losses, AND NOT a stacked set of greater-yet losses, needless extra spend, want of programming, and FAR more hard-to-replace stuff to fail. Dumb-old motors do OK there. Electronics PCBs not in an air-conditioned Telco // Data center do NOT do so well.

It is a "challenging" climate and Biosphere. VERY!

Having worked in the Phillpines (ETPI and PLDT), I'd also submit that your equipment is at greater risk of "vanishing" than using too much power or reaching extreme age. Buying what you need from local sources, in-barrio as well as in-country can reduce that risk. It's a "tribal" environment. Auslander's goods are but free food.

But that's a different set of "War Stories".

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Thank you for your advice, Thermite. I honestly did not know there were people out there with so much knowledge and experience because when I talk to the compressor manufacturer's they are usually pretty insecure.

Anyway, you said I would be safe using the Sullair ST709, even though it is 89% efficient and the Atlas is 93% and the Kaeser is 90%. For my oxygen generator, I just need a steady flow of compressed air--nothing fancy.

Can anyone assure me that Sullair Shoptek is a realiable compressor for the long-haul -- or even for limited use of 40 hours per week. When I get to the Phillippines, I don't want to mess around with importing spare parts.

Thank you again for everyone's help with this. I never realized I would receive so much support!

MarkDeRosa said:

Thank you for your advice, Thermite. I honestly did not know there were people out there with so much knowledge and experience because when I talk to the compressor manufacturer's they are usually pretty insecure.

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It's one of the most diverse and complex places as calls itself a single nation. Do some research. Any level of competence needed is THERE. One could even class it an "over educated" country, but most grads have to leave it to find a decent income well below their level of education, then send money home to large extended families. I did say "tribal".

Durability in a hot, wet, tropical fungus ridden, rain and hurricane-cursed climate should be waay above minor diff in theoretical efficiency as your metric. The locals will be using what JFW. They are GOOD with machinery, even very high-tech electronics.

For my oxygen generator, I just need a steady flow of compressed air--nothing fancy.

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No shortage of industrial gas experience there, either. It's a country impoverished by its own corruption and high birth-rates, not by lack of brains or training.

You need to do a LOT more research on your environment and its people. Everything you can find won't be quite enough. I did say "complex?"

Add "feudal" to "tribal", BTW. A few "great houses" - extended families, long entrenched - hold sway over most parts of the economy that the outside world would consider important.

As is their wont, not all the locals even bother to notice. They have their own ideas about what it is "important".

Peaceful people when they are allowed to be, but not many of Imperial Japan's forces as went there lived to write about it, and not many since leave with even a Bic Biro to write WITH!

Do yer homework. Go at least back to WWII. It did not last a hundred years, but it set the country back nearly that far, not all of that from Japanese hands. It still hurts in many ways.

Hi, I just found out that the outlet temperature of the Sullair Shoptek rotary screw compressor is 80ºC which is much higher than that of Atlas and Kaeser, so I think I need to consider one of those 2 for my single phase derated VFD retrofit project. I would like to ask which motor is better suited for a retrofit?
1) The variable speed compressor model has an AC squirrel cage motor. In this project I would replace the VFD with a larger derated VFD, and then throw away the EMC filter and the DC Choke, and finally add an AC Load reactor for single phase choppy power issues.
2) My other option is a fixed speed PM motor. In this project I would only add a derated single phase VFD and AC Load reactor.

If I have not asked too many times, here, could you guide me again? The Sullair is too hot for PSA oxygen separation, so I think I think I need to apply my derated retrofit to either a fixed speed compressor with a PM motor, or a variable speed compressor with an AC squirrel cage motor. -Thank you in advance!