Converting frequency on US devices (60Hz - 50Hz)

[and.and]

Hi friends, hope this is the right session where to post this thread..
first of all hank you so much for the opportunity to write herei'm looking for a solution to make it work in Italy an USA air dryer.The air dryer is compatible with 120V/60hz 15amp, in Italy we use 230V 50HZ. I am looking to design my own frequency converter / circuit even rewinding he motor, Another option is to make it work with an inverter which should still provide the correct voltage & 60Hz frequency sinewave output.
as you can imagine i am looking any way possible to make this air dryer work in italy, i really need his particular model to work in Italy and implement it in my wife air saloon.
Thank you really in advance everybody that give me any support and even willing to work with me on his project
Best regards Andrea

 

[MaxHeadRoom78]

So the third forum and still not satisfied with the answers?
AND you haven't answered what is the nature of the AIR dryer?

 

[rjenkinsgb]

The mention of a Salon makes this a HAIR Drier.

The frequency difference should not be a problem.

All you actually need is an appropriate transformer to reduce the supply voltage, to the appropriate level.

Induction motors will naturally run slightly slower on 50Hz than 60Hz, but that is not generally a problem and many types are marked with ratings for both frequencies.

If it's a "Universal" motor (brushed with series field) then they are not frequency dependant - 50/60Hz does not matter, just the correct voltage to set the speed.

 

[Diver300]

Some hair dryers use DC motors, where the DC is full-wave rectified from a section of the heating element. They certainly won't mind a different frequency of mains.

Some hair dryers reduce the power for the low settings by adding a diode in series with the heating elements on low power.

I cannot see any need to keep the waveform as a sinewave for a hair dryer, which is a difficult thing to do.

 

[Nigel Goodwin]

Some hair dryers use DC motors, where the DC is full-wave rectified from a section of the heating element. They certainly won't mind a different frequency of mains.

Some hair dryers reduce the power for the low settings by adding a diode in series with the heating elements on low power.

I cannot see any need to keep the waveform as a sinewave for a hair dryer, which is a difficult thing to do.

The entire scheme is flawed - all that's needed is a simple (and fairly cheap) auto-transformer to correct the voltage, the frequency will either make no difference at all, or very little difference.

 

[MaxHeadRoom78]

This has already been covered in other forums with virtually the same answers, also questions, but the OP has yet to respond.

 

[For The Popcorn]

There is a plague of people cross-posting to multiple forums, and posting the same question multiple times in each.....and then ignoring all the replies anyway. Wastes everybody's time.

 

[rjenkinsgb]

Off-the-shelf power tool transformers should work fine for what the OP needs, eg. this type of thing:

110v 3kVa Transformer with 2x16 amp Outlets

110v 3.3kVa Transformer with 2x16 amp Outlets. Features and benefits: Tool Rating 3.3Kva Output Sockets. 2 x 16amp. Transformer Specifications: Input 240 volts 50Hz single phase Complete with 2 metres of 3-core flexible cable to BS6500 for connection to mains supply and a 13 amp plug

dustarrest.com

 

[MaxHeadRoom78]

I don't believe Italy uses job-site transformers?
With more info it could be just a case of connecting any heater elements in series, if they are in a bank of more than one single element.
The motor would just need a small transformer.
We may never know as the OP appears to have bailed?

 

[rjenkinsgb]

There is a plague of people cross-posting to multiple forums, and posting the same question multiple times in each.....and then ignoring all the replies anyway. Wastes everybody's time.

Reminds me of a quotation:

The definition of insanity is doing the same thing over and over and expecting different results. -Albert Einstein.

Or even;

Ye cannae change laws of physics, Jim

 

[For The Popcorn]

I came across this recently. It needs the following addition: ....or never looks at the answers given.

 

[MaxHeadRoom78]

Or completely ignores any request for more info?

 

[and.and]

Sorry everybody for replying late, i really was watching email entering my phone of you all people replying me, i was full of appreciation but still couldn't make to rush on the computer. i was over busy the past 24 hours had to fix some expiring documents

i went online to check for the best communities to help me solve his problem , and i didn know most of you join both of them i really appreciate you all !!

please don't be angry with me

if i can briefly give some info about the hair dryer which i miss in my main post and i apologize for that

so here is The link of the product https://myrevair.com/products/revair

as you can see in the Tab spec of the product it is clearly mentioned :
“RevAir is compatible with 120V/60hz 15amp outlets only. The device will not operate with the use of a power converter, adaptor, or transformer”

now i have read online that people have imported this product and tried with a step down voltage inverter but it was no sufficient as they have melt the hairdryer.

so i really don't know how to get a solution for his i googled for a hz converter and they are industrial type super expensive (i even found product like this https://www.polskieprzetwornice.pl/...500w/?osCsid=bbdc511bb2e293282eab07181f9b9cee but the limit is 500w), anybody that is willing to help me i'm willing to pay because i'm serious about his project
sincerely Andrea

 

[For The Popcorn]

Worse yet – cross-posts to a number of different forums, and ignores all replies.

 

[rjenkinsgb]

The cost for each unit to power one drier would be far more than the cost of the driers.
For absolutely perfect power, the only practical solution I can see would be a motor-generator set with high enough ratings to power whatever number of driers were needed.

It could be with the weird design of those revair units that the slight reduction in airflow from running them on 50Hz rather than 60Hz is enough for them to overheat and have problems.


A quick search shows that they did have some form of "UK Release event" (in 2019?) - so units designed for 230V 50Hz - but no sign that they were ever actually sold, from what I I've found so far.

RevAir Launches In The UK -

We all wish that there were more hours in the day, so why ... Read More

www.salonbusiness.co.uk

I tried RevAir a weird hair dryer and here are my thoughts - Beauty and travel from journalist Fani Mari | BREAKEVEN

I tested the brand new RevAir hair dryer that dried and straightened my whole hair in record time. Read on for my honest opinion!

breakevenlondon.co.uk

As the makers site says that use outside of the USA voids the 30 Day warranty (!!!)* it could well be that the machines were either not sufficiently reliable, or not compliant with EU safety requirements, so makers were unable to get the CE marking qualification for safety etc. to allow them to be sold?
Or the two year warranty and (UK at least) six years fit for purpose / merchantable quality was too much of a risk??

They should have been making more profit at the UK price?? I'm just guessing, but regulatory problems seem more likely than retail pricing?
(Or some other company has a conflicting patent in Europe?)

* The makers guarantee / warranty makes no mention of any possibility of service after that 30 days, from what I can see??

 

[For The Popcorn]

I'm kind of cranky today.....

A friend/acquaintance asked if I could replace the capacitors in her RV (caravan) battery charger/AC-DC converter. I had her send the board, ordered the required caps, replaced them and delivered the board back to her. The caps were very slightly bulged, and the charger is from the '70s, so it seemed like a reasonable fix.

When I got there and we were talking, they described the actual problem they were hoping to fix. There had been a dead short across the battery while the charger was on, and now the charger drains the battery in a few hours if it's not on. Arrgghhh. That's not a capacitor problem. I wish they has told me that before!

There are two beefy mosfets and two dual diodes mounted to large heatsinks, so I suspect problems with those, but troubleshooting and repair doesn't fit into their time frame. They'll add a power switch to disconnect the charger when it's not powered.

The next day, they send a picture of a loose blue wire the has a socket on the end (single pin). "Our RV refrigerator does not work on AC. Where does this wire go?" It looked like it may have come off a post on a pcb, so I asked for the model number of the refrigerator. It took a half-hour exchange of messages to get that.

Turns out the 6" cable with a tip jack, hanging out of a multipin connector is a test point – don't know what for, as none of the documentation lists a test point other than where the loose wire is described. I highlighted the AC power connections on the block diagram, and asked them to measure if there was power at those points. There was also a description of problems caused by a defective heater (part of the gas cycle), so I took a screen shot of that and sent it too.

Another half hour exchange of messages, finally ending with "Yes, there's AC power where it plugs in." What about at the board itself? "We don't know where to measure that." The diagram I marked up shows you exactly where to measure. Four hours later I finally got an answer to that. I asked about measuring the heater resistance. "What, there's a heater in a refrigerator???" Yeah, as it says on the second picture I sent to you six hours ago.

"Oh, by the way, I've had to tap on the LED/switch panel to get it to work for a while." Mind you, this was more than 6 hours after the frustrating exchange of messages started!

"Sorry, I think it's got bigger issues than I can guide you through remotely."

After the charger revelation, you'd think I would know better, but the problem on the refrigerator seemed to be fairly well described. I'm out of practice digging out all the details on troubleshooting jobs.

 

[Diver300]

as you can see in the Tab spec of the product it is clearly mentioned :
“RevAir is compatible with 120V/60hz 15amp outlets only. The device will not operate with the use of a power converter, adaptor, or transformer”

It's obviously untrue that the hair dryer won't operate with a transformer, because all premises that are supplied by the electricity grid have the power come through a transformer.

However, the hair dryer is rated at 60 Hz, 13.5A and 120 V so that is quite a lot of power to transform and there's no such thing as a travel adaptor that will transform the power correctly.

A site transformer will be fine, but the output will be 50 Hz. The one linked to is around 18 kg so RevAir will be assuming that no-one will be using one of those.

The hair dryer contains heaters and electronics to run the motors. The heaters will work just the same on 50 Hz as on 60 Hz, and I think that it is highly unlikely that the electronics will be affected by the frequency.

You could buy a 2 kW petrol generator made to American specifications.

If you're prepared to open one of the RevAir units up, and show us what is inside, we could better advise what you need to do. It might be possible to feed the heaters from one power supply and the electronics / motor from another one. The electronics / motor might not like 50 Hz, but would be small enough to run from a good quality frequency inverter. The heater will be able to run from a transformer at 50 Hz.

 

[and.and]

motor-generator set with high enough ratings

thank you so much for our repl
please can you share with me a link of what you mean by this , is that a fuel generator That you mean ?

but no sign that they were ever actually sold,

Yes they were actually sold over the uk but after he covid revair cu he exportaion to uk

Or some other company has a conflicting patent in Europe?)

last i check he have patented the product over he main emerging market and so the whole europe including UK ill 2035, so he have secured he maket...

 

[and.and]

It's obviously untrue that the hair dryer won't operate with a transformer, because all premises that are supplied by the electricity grid have the power come through a transformer

yes this was he feeling that i got when readed That statement is like they want to discourage people even before thee try

You could buy a 2 kW petrol generator made to American specifications.

iam really considering this one as the very last option but thank you again i appreciate

If you're prepared to open one of the RevAir units up, and show us what is inside, we could better advise what you need to do.

yes please this is my ultimate goal of open and to put hands on it and close i as full clean working machine, i would needed to be guided and this your message encourage me, i will have to order his Revair asap

 

[rjenkinsgb]

please can you share with me a link of what you mean by this

jemelec.com