Help: converting 230V (1ph) 50Hz machines to run on 220V (1ph) 60Hz supply

[Bojam]

We're moving to Brasilia, the capital of Brazil, in a few months. The power supply there is 220V 60Hz. All my handheld power tools, with universal motors, should be fine as they are rated for 50-60Hz supply. But I don't know what to do with my larger machines (combined planer-thicknesser, bandsaw, large extraction unit), which are all induction motors rated for 50Hz input.

I'm not electrically/mechanically trained. I have read conflicting advice regarding whether it is possible (or desirable) to run 50Hz rated induction motors on 60Hz supply. The major obstacle seems to be that they may not actually work at all since the motors may not get up to speed during the surge on start-up ("a 50Hz motor placed into 60Hz service may switch off the start winding at too low a speed for the motor to make the transition to running").

As I see it, there are (at least) 3 options:

1. Sell the machines here, recoup as much as I can, and replace when we arrive.

2. Swap out the motors for 220V 60Hz motors. Keep the original motors for when we move home (France). If I go down this route, can anyone advise me on how to go about identifying suitable replacements. What technical info is required to select motors that are properly specified and will fit (dimensions, mounting plates, etc)?

3. Buy a frequency converter. These exist to convert 220-240V 60Hz input supply to 220-240V 50Hz but seem very expensive when you need to ensure they can handle large loads. My planer-thicknesser has a 3Kw motor and you need to allow for the start-up surge which apparently means specifying a model that can handle 6 times the load. In addition I would be running the extractor at the same time (unless I sell and replace the extractor with a something I find there).

If anyone has expertise to share I'd be very grateful. I'm really not sure what the most sensible course of action is. Happy to provide specific details of the machines if required.

Apparently machines in Brazil are expensive and the quality can be somewhat inferior. I do like my existing machines and would prefer to keep them if poss. Shipping costs are unlikely to be a factor because we have a large allowance from my wife's employer. Customs is another issue but my current understanding is that I am permitted to bring in tools for professional use (tax / customs duty free) but only during our initial arrival - i.e. I can't purchase and import machines tax/duty free at a later point. Having them shipped does worry me a bit, will they arrive in one peice? That said, they arrived here in working order having travelled from Taiwan -> France -> South America (we live in French Guiana) so I guess they can be properly crated again.

The other complicating factor is that we can't rent a property in Brasilia until we have arrived and got the required paperwork (temporary accomodation for a month or so while we get this sorted). So I can't know in advance what space we will have. Houses are large but whether we will be able to find/afford something with a garage / outbuilding / dedicated workshop space is kind of unknown. I have seen some suitable properties online but of course these won't still be available in August/September. I guess this makes selling the machines more sensible but I don't know.... What would you do?

Thanks in advance!

 

[Spectric]

Hoiw many machines ? This move seems temporary, you mention moving back to france so what is the timescale ?

If your move is short then maybe leave them behind for when you return and buy the machines when you have a place rented and know how much space in Brazilia. The increased frequency will increase the speed but more importantly it depends upon the type of motor, with 60Hz not only will it run faster but it could operate the centrifugal switch earlier and therefore effect the speed. Increased frequency will also cause the motor to run hotter and increase the stress on the windings and really if you are going to use them then it will require an expensive invertor VFD to correct the frequency. It would be better to maybe swap out the motors, take them out and leave in France and then get new motors in Brazilia where the 60Hz motor will be available and also save some weight in transport.

 

[ChaiLatte]

"a 50Hz motor placed into 60Hz service may switch off the start winding at too low a speed for the motor to make the transition to running"

Please provide a reference for that statement.

Please provide two more alternative, reliable sources that say the same thing.

You would seek a second opinion from a doctor. Why would you put so much faith in the single website that makes that statement in support of selling its own products?

Given that you can pull start a motor with a faulty start capacitor in the same way you pull start a lawn mower (wrap a piece of string around it and heave), the speed at which the start windings are needed to provide the initial impulse would appear to be very low.

You could experiment: wire a manual switch into the starting circuit of a motor you have and see at just how low a speed you can operate the switch and the motor still start.

 

[Bojam]

It’s a quote. Click the link to see the full article.

 

[Bojam]

Please provide a reference for that statement.

Please provide two more alternative, reliable sources that say the same thing.

You would seek a second opinion from a doctor. Why would you put so much faith in the single website that makes that statement in support of selling its own products?

Given that you can pull start a motor with a faulty start capacitor in the same way you pull start a lawn mower (wrap a piece of string around it and heave), the speed at which the start windings are needed to provide the initial impulse would appear to be very low.

You could experiment: wire a manual switch into the starting circuit of a motor you have and see at just how low a speed you can operate the switch and the motor still start.

I don’t put full faith it what they say. That’s why I’m here asking for well informed opinion.

 

[Bojam]

Hoiw many machines ? This move seems temporary, you mention moving back to france so what is the timescale ?

If your move is short then maybe leave them behind for when you return and buy the machines when you have a place rented and know how much space in Brazilia. The increased frequency will increase the speed but more importantly it depends upon the type of motor, with 60Hz not only will it run faster but it could operate the centrifugal switch earlier and therefore effect the speed. Increased frequency will also cause the motor to run hotter and increase the stress on the windings and really if you are going to use them then it will require an expensive invertor VFD to correct the frequency. It would be better to maybe swap out the motors, take them out and leave in France and then get new motors in Brazilia where the 60Hz motor will be available and also save some weight in transport.

Hi Spectric, thanks for your reply.

I have 3 large machines (PT, bandsaw, cyclonic extractor). All single phase induction motors. The PT is 3kW, bandsaw and extractor both 1.5kW I think.

Timescale in Brazil: 2-3 years for sure, possibly 5-6 years if things work out.

We live in French Guiana at the mo (a French overseas territory neighbouring Brazil and Suriname in South America). The options are to sell here or take with us. We’re not shipping anything back to mainland France so I can’t stash them there for later. When we leave Brazil we will probably move back to France but that’s not 100% certain.

So if I want to keep them and run them in Brasilia then you think the better option (rather than an expensive frequency converter / VFD) would be to change out the motors? Since I’m pretty ignorant on all things mechanical / electrical, any advice on how to specify and locate appropriate replacement single phase 220-240V 60Hz motors. I guess it would make sense to purchase these locally in Brazil (where they should be easier to source) but how can I make sure that the replacements are the right spec, physical size, etc? Sorry if these seem dumb questions but I have no experience doing this and want to make sure I can find what I need and get a sense of price, etc.

Cheers!

 

[Fireburst]

Not sure if this helps:

https://acim.nidec.com/motors/usmotors/TechDocs/ProFacts/Voltage-Frequency-Variation

 

[Jameshow]

How about shipping a petrol generator out with them??

 

[BucksDad]

Rather than petrol generator, why not look into one of those large capacity batteries which can output 3KW (Ecoflow I think was spending lots of money on YouTube).

No messing around with changing motors or anything like that

 

[Spectric]

How about shipping a petrol generator out with them

That is certainly another option, I have known people do it to run large three phase machinery when they only had a single phase supply so a non Brazilian generator would be another solution and maybe cheaper than changing motors.

 

[Spectric]

one of those large capacity batteries which can output 3KW

That will give 0 Hz as a battery is Dc and then you would need an invertor to produce the 60 Hz output .

 

[BucksDad]

That will give 0 Hz as a battery is Dc and then you would need an invertor to produce the 60 Hz output .

I meant something like this Spectric which gives you AC

https://uk.ecoflow.com/products/delta-pro-portable-power-station

 

[Spectric]

I meant something like this Spectric which gives you AC

I think a generator is a cheaper option than one of those although they would be a quieter option.

 

[Jameshow]

Rather than petrol generator, why not look into one of those large capacity batteries which can output 3KW (Ecoflow I think was spending lots of money on YouTube).

No messing around with changing motors or anything like that

That would work not even a lithium battery just a decent Leisure battery with a 3kw inverter would be fine for intermittent use. Charge it up using a local battery charger. Not efficient but would work.

 

[Inspector]

What do the makers of these machines say about running 60Hz? Do they have different motors ie different part numbers for the two markets or are they the same? Most of mine say 60Hz except for a belt/disc sander 6"x 48" with a 12" disc that says 50Hz/60Hz. It was made in Taiwan.

Pete

 

[Sideways]

I accept that a motor that has been optimised for 50Hz MAY have some issues running on 60Hz, but I've seen enough motors with rating plates setting out their speed and full load current for both 50Hz and 60Hz supplies that my expectation is that your 50Hz machines will start and run on 60Hz. They will run fast as speed is related to the supply frequency. They MAY run a little hotter but motors in DIY machines aren't usually pushed very hard, so if they are rated for continuous duty (it'll be on the rating plate) I would keep an eye on them at first but wouldn't anticipate great problems.
Modern motors of any quality are made to standards like IEC or NEMA. These specify the physical dimensions of the motor and are intended to make it easy to replace a motor with another of the same "frame size" and have it fit without adapting anything.
My instinct in your situation would be to take your machines, use them, and if you do find any of them run uncomfortably hot, just swap the motor for one of the same dimensions. If you buy the replacement in Brazil, then you should be buying one that works ok on 60Hz.

 

[thikone]

I changed induction motor on my drill press because the one it came with had bent axel and was vibrating like hell...

And since I was changing it I opted for 400V three phase one, that can be wired for 230V delta, and a good VFD. That costed like 200 EUR in total but now I can control the frequency/RPM and have a slow start and electric brake. And three phase motors are more powerful and efficient and have more torque.

So, that is the most solid and sensible upgrade I think, if you start to change motors... 3kW will cost more but in my opinion it is worth that.

It is not possible to share one FVD for multiple motors though. And it has to be close to the motor, like be mounted on the machine.

 

[Bojam]

What do the makers of these machines say about running 60Hz? Do they have different motors ie different part numbers for the two markets or are they the same? Most of mine say 60Hz except for a belt/disc sander 6"x 48" with a 12" disc that says 50Hz/60Hz. It was made in Taiwan.

Pete

Hi Pete,

I spoke to the boss of Holzprofi France (who sell the machines, manufactured in Taiwan). He said they would probably run fine but that the higher frequency might reduce the lifespan of the motors.

As far as I know the machines are only sold in the European market so Holzprofi don’t spec 60Hz motors. I asked and they weren’t able (or willing) to advise on suitable 60Hz replacements. Grizzly (US) have a model of 17in bandsaw that is more or less identical to mine so I could find out what 230V 60Hz motor they use.

I’ll probably do as Sideways suggests and take the machines and run them with the existing 50Hz motors. If they don’t work or there are performance issues then I can swap the motors out for locally available replacements.

James

 

[Bojam]

I accept that a motor that has been optimised for 50Hz MAY have some issues running on 60Hz, but I've seen enough motors with rating plates setting out their speed and full load current for both 50Hz and 60Hz supplies that my expectation is that your 50Hz machines will start and run on 60Hz. They will run fast as speed is related to the supply frequency. They MAY run a little hotter but motors in DIY machines aren't usually pushed very hard, so if they are rated for continuous duty (it'll be on the rating plate) I would keep an eye on them at first but wouldn't anticipate great problems.
Modern motors of any quality are made to standards like IEC or NEMA. These specify the physical dimensions of the motor and are intended to make it easy to replace a motor with another of the same "frame size" and have it fit without adapting anything.
My instinct in your situation would be to take your machines, use them, and if you do find any of them run uncomfortably hot, just swap the motor for one of the same dimensions. If you buy the replacement in Brazil, then you should be buying one that works ok on 60Hz.

Thanks Sideways, this is a really helpful!

 

[Bojam]

I changed induction motor on my drill press because the one it came with had bent axel and was vibrating like hell...

And since I was changing it I opted for 400V three phase one, that can be wired for 230V delta, and a good VFD. That costed like 200 EUR in total but now I can control the frequency/RPM and have a slow start and electric brake. And three phase motors are more powerful and efficient and have more torque.

So, that is the most solid and sensible upgrade I think, if you start to change motors... 3kW will cost more but in my opinion it is worth that.

It is not possible to share one FVD for multiple motors though. And it has to be close to the motor, like be mounted on the machine.

Thanks, this is definitely worth considering if the existing motors won’t run (well) on the 60Hz supply.