Using a 60hz mains device in the UK

[monchavo]

On holiday in South Korea I noticed a plethora of coloured energy saving bulbs which looked rather aesthetically pleasing. I bought a blue one and brought it home (UK) plugged it into the UK mains (into a circular screw thread lamp fitting) and it appears to be working fine. The operating conditions on the side of the box said 220v at 60 hz which is what I believe S. Korean electricity runs at.

Now, a rice cooker from Korea has just arrived, telling me that it too will operate at 220v/60hz (500w at 2.3a)....

Clearly, a lightbulb is a less complex object than a rice cooker... Do I require a converter, or will the rice cooker work okay on my UK mains? Are there risks? Possible component stress? Anything I should be aware of (apart from changing the plug...)

Your valuable experiences much appreciated

monchavo

 

[rbulsara]

Rice cooker is even a simpler device than a bulb, believe it or not. It is just a resistive heater coil and could not care less for frequency.

 

[logbook]

Interestingly, a passive device like a heater is happier on a lower voltage; less stress. A switched-mode supply would try to keep the power constant and therefore the current would increase but a simple resistive load can't do that.

Just to make your day I should point out that bringing a non-CE marked electrical appliance into the UK (effectively importing it) and putting it into service is actually a criminal offence. If you get electrocuted the government will probably imprison your dead carcass just to make a point.

In the case of a rice cooker the safety aspects are of more concern than the EMC directive.

 

[MacGyverS2000]

A ricecooker is less complex than the lightbulb... unless said ricecooker has a digital controller (welcome to the age of sub-$1 throw-away microcontrollers).

Dan - Owner

http://www.Hi-TecDesigns.com

 

[monchavo]

Splendid. When I said more complex, I meant more parts (including some that move). Thank you for the excellent advice. I knew I could count on you wonderful chaps.

Kimchee, anyone?

 

[jraef]

Moving parts on a rice cooker? Well that's a diferent story then. Moving parts implies motors and motors are definately affected by frequency and voltage. What the heck moves on your rice cooker? The lid?

http:/

http://www.jraef.com

Eng-Tips: Help for your job, not for your homework Read faq731-376

 

[Skogsgurra]

Maybe it's a jap bike. They are sometimes referred to as "rice cookers". Lots of moving parts there...

Gunnar Englund

http://www.gke.org

 

[itsmoked]

No skogs, that's Rice Rocket .

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Warpspeed]

Not sure about your rice cooker, if it just has a heating element it should be fine.

If it has a motor driven timer, it may not be too happy, apart from running slow, the motor will run hotter. None of that may matter in practice.

 

[ScottyUK]

We've missed the point that the UK with its notional 230V 50Hz supply still pumps out 240V in almost all locations. The 230V nominal supply in Europe has very broad tolerances to allow the distribution infrastructure of Europe (historically 220V) and the UK (historically 240V) to comply with the new 'standard' of 230V. Eventually Europe will all become 230V as assest on the netwrok are replaced, but I doubt it will be within my lifetime.

The 220V lamp or heater is running at nearly 10% overvoltage. The rice might cook a little quicker, but the filament lamp will not last as long. Enjoy it while it is working!


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I don't suffer from insanity. I enjoy it...

 

[monchavo]

Other users of similar Korean produced rice cookers in the UK have expressed the same - that their cookers fail every few years and have to be replaced, due to the filaments giving up the ghost. The 10% extra voltage I suppose is a good reason!

 

[rbulsara]

If the cooker parts run hotter, the rice will get cooked faster..no problem.

could not resist!!!

 

[analogkid2digitalman]

Rice burner?

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"It's the questions that drive us"
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[jraef]

I still want to know what moving parts there are in a rice cooker...

http:/

http://www.jraef.com

Eng-Tips: Help for your job, not for your homework Read faq731-376

 

[monchavo]

The lid?

 

[Skogsgurra]

I think you made a great job there Jeff. But I miss water level sensor. Or is that included in the weight sensing? I see a problem differentiating between water weight and rice weight.

Tangent alert!!!

Can you please add the following blocks to your diagram:

1 A sensor and comparator for rice.

2 A sensor and comparator for rice + water

3 A sequential circuit that a)promts for rice b)prompts for water c)checks that lid is on d)starts cooking.



Gunnar Englund

http://www.gke.org

 

[logbook]

I can't believe I failed to spot the mismatched voltage direction. I was answering in terms of the applied voltage being lower than rated!

10% over-voltage means 20% over power and therefore 20% over-temperature =VERY BAD. Now typically devices are rated for 10% over-voltage, at least, so it shouldn't immediately fail, but like I said earlier you are asking for trouble legally. Suppose a guest touches it and gets an electric shock. You will be in deep doo-doo legally as you are already a criminal for importing it.

 

[monchavo]

I posted this thread in order to understand the implications of connecting this device to the UK mains, and any detrimental effect that that might have on the unit.....

Not sure I follow the logic of why does 10% over-voltage means 20% over power?

Clearly a hotter rice cooker is going to cook the rice quicker, I shall have to factor that into my assessment when I am adding rice and water....

In regards to your comment about a "guest touching it and gets and electric shock", is the fact that the unit is operating outside of it's designed parameters going to make a shock more likely?

 

[Skogsgurra]

1.1 squared is 1.21 - that's why power is 21 percent higher when voltage is ten percent higher.

Now, the 220-> 230 vs 240 -> 230 V change is over. So even UK should be close to 230 V. But, of cours, ScottyUK knows. He lives there.

Gunnar Englund

http://www.gke.org

 

[itsmoked]

How are you going to cook the rice faster? 212 degrees is as far as you're going. It might heat to a boil faster but also might drive off the water faster leaving too little for proper rice absorption.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com