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Electronics => Beginners => Topic started by: ivaylo on October 08, 2018, 03:18:44 pm

Title: Running an US Fridge Compressor in Europe?
Post by: ivaylo on October 08, 2018, 03:18:44 pm
Hey guys,

A friend moved from the US to the Netherlands. Got her US wine fridge with her. The controls, displays, etc. all work, but compressor won't turn with any of the adapters she's tried (labels pictured). Must be the frequency difference (no idea if those adapters convert frequency, guess not), but I was expecting it if not run extended periods of time to at least turn?

Any product on the market which could help her?

Appreciate your help,
Ivaylo
Title: Re: Running an US Fridge Compressor in Europe?
Post by: abraxa on October 08, 2018, 05:26:32 pm
I'd say those adapters don't work because the surge current of the motor is HUGE since it's essentially stalled on startup, likely forcing these into overload shutdown.

This fridge is so small, I'd invest in a real transformer. Something like these:
https://www.ebay.nl/itm/Heavy-Duty-Step-Down-Voltage-Converter-Transformer-300W-240V-to-120V-UK-to-USA/121525710587 (https://www.ebay.nl/itm/Heavy-Duty-Step-Down-Voltage-Converter-Transformer-300W-240V-to-120V-UK-to-USA/121525710587)
https://www.ebay.nl/itm/TOYOZUMI-TRANSFORMER-SD21-02KB-PRI-200-240-V-VOLT-SEC-100-115-V-2-KVA-CAP-TR2/291560158620 (https://www.ebay.nl/itm/TOYOZUMI-TRANSFORMER-SD21-02KB-PRI-200-240-V-VOLT-SEC-100-115-V-2-KVA-CAP-TR2/291560158620)
Title: Re: Running an US Fridge Compressor in Europe?
Post by: capt bullshot on October 08, 2018, 05:34:11 pm
The usual fridge compressor motor relies on the line frequency.
Using a proper (and large enough) transformer, most probably it'll start to run, but will run slower than intended and may have increased power consumption. Both will result in decreased efficiency of the fridge. One might try some combination of charger, large enough battery and 60Hz / 120V inverter with large surge power capability, or just get a new fridge.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: BrianHG on October 08, 2018, 08:03:28 pm
For a whine cooler made in China, it will cost you less to buy a new 240v50hz one than converting 50hz to 60hz with something like a true sine wave inverter connected to a DC power supply with enough startup surge current support for the compressor.

You also have to worry about the inverter setup being safe if you go the homemade solution.  Getting a proper 60hz sinewave out with that startup surge current support will cost money.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Karlo_Moharic on October 08, 2018, 09:04:21 pm
For a whine cooler made in China, it will cost you less to buy a new 240v50hz one than converting 50hz to 60hz with something like a true sine wave inverter connected to a DC power supply with enough startup surge current support for the compressor.

You also have to worry about the inverter setup being safe if you go the homemade solution.  Getting a proper 60hz sinewave out with that startup surge current support will cost money.

Yep  :-+
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Karlo_Moharic on October 08, 2018, 09:40:59 pm
It can also be the case that motor got damaged during transport
Title: Re: Running an US Fridge Compressor in Europe?
Post by: tooki on October 09, 2018, 12:11:51 am
See how that converter says "Converter Mode for hair dryers only"? It's probably the kind of converter that is basically a triac dimmer permanently set to halfway. I'm no expert on motors and magnetics, but my hunch is that the compressor motor (or the control electronics for it) simply cannot function with the chopped-up sine wave from those. Try a real transformer — and as others have said, a beefy one.

Or just buy a new wine cooler.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Zero999 on October 09, 2018, 12:25:57 am
I agree, the converters already tried are probably thyristor based and give a horrible waveform, only suitable for resistive loads such as hair dryers. It's possible that using such an adaptor on a fridge could either damage the motor, the adaptor or both. If it won't work on a transformer now, I suspect the motor got burnt out when it was powered from the crappy adaptor.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: ivaylo on October 09, 2018, 04:20:03 am
Thanks guys! These are more alternatives of why it possibly doesn't work than I would have listed without seeing the thing...
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Wolfgang on October 09, 2018, 10:36:15 am
There is one more problem that needs to be solved:

The motor will need 60Hz to run properly. While average power is not too much, the type of motor built into refrigerators consumes an insane amout of inrush current while starting.
The inverter creating 60Hz must be pepared to supply this current. So you dont need a 85W inverter, you need a 1kW inverter instead. The inverter must also be OK with a highly reactive load.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: alpher on October 09, 2018, 12:59:22 pm
There is one more problem that needs to be solved:

The motor will need 60Hz to run properly. While average power is not too much, the type of motor built into refrigerators consumes an insane amout of inrush current while starting.
The inverter creating 60Hz must be pepared to supply this current. So you dont need a 85W inverter, you need a 1kW inverter instead. The inverter must also be OK with a highly reactive load.
Not to mention a shitty euro type mains network, unable to supply the staring current.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Wolfgang on October 09, 2018, 01:10:27 pm
Sorry to disagree, but the mains in Europe (at least in Germany) is a *lot* stiffer than in the States.
A statistics of power downtime tells a lot.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Nusa on October 09, 2018, 01:50:23 pm
This is one of those cases where the cost of a proper solution will equal the value of that fridge. (Which is about $300 new.) Unless you've got other appliances that can share the same solution, it's likely better to buy a replacement fridge locally.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Monkeh on October 09, 2018, 02:02:35 pm
There is one more problem that needs to be solved:

The motor will need 60Hz to run properly. While average power is not too much, the type of motor built into refrigerators consumes an insane amout of inrush current while starting.
The inverter creating 60Hz must be pepared to supply this current. So you dont need a 85W inverter, you need a 1kW inverter instead. The inverter must also be OK with a highly reactive load.
Not to mention a shitty euro type mains network, unable to supply the staring current.

Beg pardon?

There are a few kiloamps available pretty much anywhere.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Mr. Scram on October 09, 2018, 02:43:15 pm
It surprises me that anyone would take their wine cooler across the ocean in the first place. Items like those generally aren't worth the hassle and cost. Maybe she just really enjoys cool wine.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: ivaylo on October 09, 2018, 04:37:35 pm
...Maybe she just really enjoys cool wine.
Yes, she does :)
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Jeroen3 on October 09, 2018, 04:53:40 pm
How many VA would you need?
Conrad is a major distributor of various electronics components not limited to business only.
They sell this 250VA transformer: https://www.conrad.nl/p/block-e-jet-250-automatische-voorschakeltransformator-e-jet-250-512972 (https://www.conrad.nl/p/block-e-jet-250-automatische-voorschakeltransformator-e-jet-250-512972)
But there is also a 1000VA version. (It has a NEMA5-15 socket)

But, I don't know how large or special this cooler is... You might be better of just getting a new one. (https://www.coolblue.nl/wijnklimaatkasten)
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Daixiwen on October 09, 2018, 06:26:31 pm
I think all it needs is a batterizer in parallel to deal with the inrush current
Title: Re: Running an US Fridge Compressor in Europe?
Post by: tooki on October 09, 2018, 08:43:15 pm
Not to mention a shitty euro type mains network, unable to supply the staring current.
As an American who’s lived in USA and Europe for about the same number of years each, I have no idea where you got the idea that Europe has “shitty” power grids. In my experience Europe does a far better job, both in terms of power quality and availability. There’s a reason why UPSs and surge protectors are super common in USA, and rarely seen here outside of data centers...
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Jeroen3 on October 09, 2018, 11:23:03 pm
The idea of shitty power probably comes from the grid time deviation we experienced begin 2018.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: babysitter on October 10, 2018, 12:38:49 am
Which was a financial thing of "unwilling to supply", I'd say grid robustness made that it only slowed the clock and didn't make the grid break into two or more parts and rolling blackouts.

Title: Re: Running an US Fridge Compressor in Europe?
Post by: alpher on October 13, 2018, 01:39:13 pm
Let me elaborate then, "a few of kiloamps" is actually a very weak network,
Minimum for any kind of dwelling should be arround , 20Ka, most  of Ontario area being in 200Ka range for most of commercial and some   of residential dwelling, and   some unfortunate souls being close to the transformer even higher (which cost serious money).
Don't wan't to start a pissisng mach  but the relative absence of star/delta starters so common in Europe speaks for itself. I've never seen one used on a motor of less that 150Hp.

Title: Re: Running an US Fridge Compressor in Europe?
Post by: james_s on October 13, 2018, 02:21:17 pm
Well UK is the closest to Europe I've been, but the arrangement at least where my friend lives is a bit different. One transformer stepping down to 240V feeds the whole street he's on, so especially near the end of the run the voltage range is pretty wide. He was monitoring his for a while and we saw everything from a low of about 220V up to a high of over 250V. I monitored mine and never saw it outside a range of 118V to a high of 121V, the standard setup here is a transformer either on a pole or a vault by the edge of the road that steps down 7200V to 120/240 feeding only a few houses within a couple hundred feet of the transformer.

Even so, that's not going to cause any trouble starting a refrigerator motor. Most stuff isn't going to mind a slightly wider voltage swing.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Monkeh on October 13, 2018, 02:57:59 pm
Let me elaborate then, "a few of kiloamps" is actually a very weak network,
Minimum for any kind of dwelling should be arround , 20Ka, most  of Ontario area being in 200Ka range for most of commercial and some   of residential dwelling, and   some unfortunate souls being close to the transformer even higher (which cost serious money).
Don't wan't to start a pissisng mach  but the relative absence of star/delta starters so common in Europe speaks for itself. I've never seen one used on a motor of less that 150Hp.

I'm sorry, what?

No normal residential installation can handle a 200kA fault current. Hell, most decent size industrial ones can't. And you're going to have one hell of a time achieving that with 120V! 20kA is already very substantial.

20kA at 240V would require an EFLI of just 12mΩ - with 4AWG conductors that's only 7.5m of cable. 200kA would involve just 1.2mΩ - that's about 3m at 0000AWG.

Would you like to try again with your brain engaged?!
Title: Re: Running an US Fridge Compressor in Europe?
Post by: NiHaoMike on October 13, 2018, 03:01:47 pm
Be on the lookout for a small used VFD and that should do the trick.

Too bad it's not the reverse (run a small 240V compressor on 120V) since there's a fairly simple solid state converter for that. Basically just rectify the mains with a voltage doubler and switch a pair of MOSFETs such that it generates 120V AC of the opposite phase, which then is combined with the incoming 120V to make 240V.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Towger on October 13, 2018, 07:51:49 pm
The fridge just needs a decent step down transformer, not the micky mouse one photoed.   The cheapest source would be a building site transformer.   All in all it would have been easier/cheaper to buy another fridge, taking the transport costs into account.

My grandmother had a big yank fridge from the 1940's to the 80s. There must have been at least a cubic foot of copper in its stepdown transformer.  It was given away and the new owners got years more out of it.  I believe it was imported from America during 'The Emergency' aka WW2 to store medicine.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: vk6zgo on October 13, 2018, 08:34:12 pm
Let me elaborate then, "a few of kiloamps" is actually a very weak network,
Minimum for any kind of dwelling should be arround , 20Ka, most  of Ontario area being in 200Ka range for most of commercial and some   of residential dwelling, and   some unfortunate souls being close to the transformer even higher (which cost serious money).
Don't wan't to start a pissisng mach  but the relative absence of star/delta starters so common in Europe speaks for itself. I've never seen one used on a motor of less that 150Hp.

I'm sorry, what?

No normal residential installation can handle a 200kA fault current. Hell, most decent size industrial ones can't. And you're going to have one hell of a time achieving that with 120V! 20kA is already very substantial.

20kA at 240V would require an EFLI of just 12mΩ - with 4AWG conductors that's only 7.5m of cable. 200kA would involve just 1.2mΩ - that's about 3m at 0000AWG.

Would you like to try again with your brain engaged?!

Yes, I can't see how any kind of domestic fridge can draw start currents of the magnitude quoted by alpher .

In any case, it will be halved by the higher voltage.
This is the main advantage of the 220/230/240v Mains--- less current for the same power.
(Also why, in North America, the so-called "split phase"  240v system is often used for major appliances.)

OK, maybe Wolfgang is correct, & the motor will not run correctly at 50Hz, but if this entails the use of an inverter, that is where the doubt about start current applies.
The start current as far as the Mains supply is concerned, is concerned will not be the problem.

I must admit, I'm a bit bemused by his reference to a star/delta starter & a 150hp motor.
Surely this presupposes a three phase supply, which has little to do with the present case.

It is too long ago that I learnt about ac motors, but I've worked around a lot of big ones & small ones.
The small ones usually have a capacitor start, which I have had occasion to change.

The big ones just trundled on virtually forever, & in the odd case of one dying, was sent off for rebuilding.
I cannot remember any external starter device associated with them that failed, so I never got to look inside them.


Title: Re: Running an US Fridge Compressor in Europe?
Post by: GeorgeOfTheJungle on October 13, 2018, 08:42:18 pm
Can't run a 60Hz AC motor at 50Hz, you're going to fry it! Why? Because the inductors are going to enter saturation => overheat => short or even worse: catch fire.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: The Soulman on October 13, 2018, 10:17:18 pm
Can't run a 60Hz AC motor at 50Hz, you're going to fry it! Why? Because the inductors are going enter saturation => overheat => short or even worse: catch fire.

Yes although running it at a lower voltage like 100 Volt might (no guarantee) avoid that its still a bit of a risk (fire hazard).

The cheapest and most practical solution is to get a new fridge.

Or less practical but should work, a beefy (remember startup current) professional power amplifier and a 50 hz oscillator.  :P
Title: Re: Running an US Fridge Compressor in Europe?
Post by: station240 on October 16, 2018, 05:04:24 am
I have to wonder if having a refrigeration technician fit a replacement compressor would be an affordable option.
Find out what model number is on the sticker attached to the compressor, see if there is a 220/240V 50Hz version.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: vk6zgo on October 16, 2018, 11:44:32 am
Can't run a 60Hz AC motor at 50Hz, you're going to fry it! Why? Because the inductors are going to enter saturation => overheat => short or even worse: catch fire.
That's why I like universal motors---- they don't care what the frequency is!
Title: Re: Running an US Fridge Compressor in Europe?
Post by: james_s on October 16, 2018, 11:47:41 am
Can't run a 60Hz AC motor at 50Hz, you're going to fry it! Why? Because the inductors are going to enter saturation => overheat => short or even worse: catch fire.
That's why I like universal motors---- they don't care what the frequency is!

They also make a hell of a racket, and they have carbon brushes that require maintenance. Wouldn't work well in a hermetic compressor.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: Zero999 on October 17, 2018, 01:14:09 am
Can't run a 60Hz AC motor at 50Hz, you're going to fry it! Why? Because the inductors are going to enter saturation => overheat => short or even worse: catch fire.
That's why I like universal motors---- they don't care what the frequency is!

They also make a hell of a racket, and they have carbon brushes that require maintenance. Wouldn't work well in a hermetic compressor.
Yes, the arcing would cause decomposition of the refrigerant, both by ionisation and photo-degradation due to the emitted UV radiation. Refrigeration units designed to work off batteries, just use lower voltage AC motors and run them of an inverter.

I have to wonder if having a refrigeration technician fit a replacement compressor would be an affordable option.
Find out what model number is on the sticker attached to the compressor, see if there is a 220/240V 50Hz version.
Probably more expensive, than buying a new wine cooler, but if that particular unit has some sentimental value, it would make sense.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: SeanB on October 17, 2018, 05:47:15 am
Pretty likely the compressor is going to run fine on 50Hz provided the voltage is correct, as most compressors are designed to run on 50 or 60Hz, as they are world wide supplied items, and making a 60Hz only version is something less economical. The lower speed will mean lower capacity and lower flow rates, but most of the time it really makes little difference in the application.
Title: Re: Running an US Fridge Compressor in Europe?
Post by: james_s on October 17, 2018, 07:10:36 am
I just looked at a small hermetic compressor I have sitting here and it does indeed say 115V 60Hz/100V 50Hz, I had never noticed that before. On 50Hz though it will be spinning 20% slower and that could result in rather poor performance, especially with domestic refrigerators which invariably use a simple capillary tube expansion device instead of a proper TXV. It won't hurt anything to try, but I'd give it a 50% chance of providing satisfactory performance. A small VFD may be a viable option, they are normally used with 3 phase motors but some of them are capable of driving a single phase motor.

Changing the compressor is something I might try as a hobby project but that's only because I already have all the tools to service refrigeration equipment. It certainly wouldn't be worth paying someone to do it though, coming up with a source of 120V 60Hz would surely be more cost effective.