Author Topic: Running an US Fridge Compressor in Europe?  (Read 1885 times)

0 Members and 2 Guests are viewing this topic.

Online Towger

  • Super Contributor
  • ***
  • Posts: 1467
  • Country: ie
Re: Running an US Fridge Compressor in Europe?
« Reply #25 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.
 

Offline vk6zgo

  • Super Contributor
  • ***
  • Posts: 4519
  • Country: au
Re: Running an US Fridge Compressor in Europe?
« Reply #26 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.


 

Online GeorgeOfTheJungle

  • Super Contributor
  • ***
  • Posts: 1587
  • Country: pl
Re: Running an US Fridge Compressor in Europe?
« Reply #27 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.
« Last Edit: October 13, 2018, 11:24:11 pm by GeorgeOfTheJungle »
int main (void) { while (1) fork(); }
 

Offline The Soulman

  • Frequent Contributor
  • **
  • Posts: 584
  • Country: nl
  • The sky is the limit!
Re: Running an US Fridge Compressor in Europe?
« Reply #28 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
 

Offline station240

  • Supporter
  • ****
  • Posts: 848
  • Country: au
Re: Running an US Fridge Compressor in Europe?
« Reply #29 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.
 

Offline vk6zgo

  • Super Contributor
  • ***
  • Posts: 4519
  • Country: au
Re: Running an US Fridge Compressor in Europe?
« Reply #30 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!
 

Offline james_s

  • Super Contributor
  • ***
  • Posts: 7783
  • Country: us
Re: Running an US Fridge Compressor in Europe?
« Reply #31 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.
 

Offline Zero999

  • Super Contributor
  • ***
  • Posts: 12169
  • Country: gb
  • Hero999
Re: Running an US Fridge Compressor in Europe?
« Reply #32 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.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15050
  • Country: za
Re: Running an US Fridge Compressor in Europe?
« Reply #33 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.
 

Offline james_s

  • Super Contributor
  • ***
  • Posts: 7783
  • Country: us
Re: Running an US Fridge Compressor in Europe?
« Reply #34 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.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf