Learning electric basics -- please correct me

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  #1  
Old 08-28-06, 03:51 PM
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Question Learning electric basics -- please correct me

Just joined -- hi to all. I want to check out my understanding of basic electrical facts. Wanna learn. Feel like I'm at kindergarten, lol!

1) My microwave is nameplated as 1.3 kW. My understanding is that 1kW is 1000 W, therefore I expected to also read on the micro's nameplate that the appliance has a wattage of 1300 W. (However, it's listed as 800W.) How come, i.e. what's the diff. between the kW and wattage rating given? What do they signify?

2) What does "500 W continuous" mean? (Was looking at a step up step down transformer just now.)

3) What's the typical amperage or wattage of a large fridge-freezer (side-by-side, or otherwise). I don't have one to check. Thinking of importing one from Asia, but need to know the amperage or wattage, so I know in advance which transformer to buy.

Thanks for reading, and plz educate me, lol, and give your answers...

Cheers,
RS ;-)
 
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Old 08-28-06, 04:08 PM
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Welcome to the forums. If you are in the US, I understand where you are going, and only have to ask, "why?" Adapting European or Asian electrical components to operate at 60 Hz on 120 volts, will be considerably more expensive at the onset, and in maintenance thereafter.
Some wattages are nameplated as maximum wattage including start surge. After it settles down, the usage will be less.
 
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Old 08-28-06, 04:34 PM
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Hi Chandler,

Thanks for replying! I'm situated in Finland, nordic Europe, and am interested in importing a 110v fridge-freezer from Japan. We're on 50 Hz, and 230v, the European continental standard. So it will be a step-down transformer that I'll need for my imported appliance.

Btw, anyone here know how it would work if I were to live in North America in future years, and take my new 50 Hz import with me? The voltage would be the same, so I'd not need a transformer (voltage regulator), but what about the difference in cycles? Would the appliance work in North America, and, if yes, would there be any operational issues nevertheless?

???

RS

PS. Can anyone please educate me too about my first post's contents, re the electrical measurement basics I asked about? Thanks in advance...
 

Last edited by Rollingstone06; 08-28-06 at 05:38 PM. Reason: Removed quote as it's unnecessary to quote the entire post directly above yours
  #4  
Old 08-28-06, 05:55 PM
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1) 800 watts is likely the power output of the microwave, and 1.3KW is likely the (maximum) power requirements. Although those numbers don't make a lot of sense.

2) Continuous means for the long haul or over time. Peak would mean for a short time. A generator, for example, might be able to supply 5000 watts continuous, and 6250 peak.

3) I son;t know, but I bet you could find this out on the web by searching the pages of an appliance manufacturer.
 
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Old 08-28-06, 10:14 PM
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The microwave isnt 100% efficent. Probably only about 70% of the power is converted to microwaves. Then there is power for controls, lights, turntable.
 
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Old 08-29-06, 06:43 AM
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Hello from Georgia (USA)
IMO...The fridge would probably run on 60 hertz...for a while. The problem is that the motor on the compressor and fan would run 20% faster at 60Hz. (60/50). The system is designed for the (cooling) gas pressure and flow (volume) that the compressor will provide at the lower speed. Increasing the flow by 20% may disrupt or damage the cooling equipment.
On the other hand, it might be fine.
steve
 

Last edited by DIYaddict; 08-29-06 at 06:51 AM. Reason: removed quote as it's unnecessary to quote the entire post
  #7  
Old 08-29-06, 06:43 AM
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A range for refrigerators based on size and energy efficiency would be anywhere from 500 to 1500 watts. The data is available on manufacturer's websites, and of course in the showroom.

On a microwave, you should find 2 ratings listed. Looking at mine, it shows 850 microwave cooking watts, 1300 watts input power.

Your main issue with bringing an appliance with large motors like a washer or refrig. is that you might have to replace the motor. Often , they will not work on the change from 50 hz to 60 hz.
 
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Old 08-29-06, 11:21 AM
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I strongly urge you to only use appliances in the country for which they were designed. Not only will the motors require significant retooling to work on different electrical systems, but the safety standards are different in each country. An imported appliance may not meet safety or energy efficiency standards in your country.

If an imported appliance causes an electrical fire, your insurance company may not pay for damages on the grounds that you used unsafe, modified appliances that were not certified for use on the native electrical system.

Regarding your original questions:

1) The 1.3 kW figure includes all electrical consumption in the appliance such as lights, vent fans, controls, etc. About 800W of that is dedicated to the actual cooking.

2) A continuous rating is what the device can operate at for long periods of time without overheating. Motors and transformers can operate well above their continuous ratings for short periods of time, but may catch on fire if they exceed the continuous rating for too long.

3) The electrical demand of a freezer depends entirely on the size and efficiency of the compressor motor. Many freezers have automatic defrost heaters which have additional power requirements beyond the compressor motor.
 
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Old 08-29-06, 11:25 AM
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You state you are on a 50Hz system. I don't know what the japaneese standard frequency is, but if it is 60Hz you will have problems. If there is just a voltage mismatch then you could solve it with a transformer, but don't forget to fuse both the primary and the secondary (extra cost). You would probably be better served by getting an appliance designed for the power requirements of your local.
 
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