Help identify this two pin plug ?

[newhobgirl]

Well, when I emailed the sellers (which I did before I bought one) to confirm that this appliance could be plugged straight into a UK 13A socket (with the provided adapter), this was the response I got

"Yes you can.
I sold over 200pcs. to UK without problems.

Best regards

Uhmeyer"

I came across a webiste about induction hobs and how they work, and how the power ratings for them work. I am struggling to understand whether the power (watts) of the appliance can change with a change in voltage and how that relates to the amps it draws.

http://theinductionsite.com/electricity.shtml says this:


"Keep in mind that there is no a prior way of knowing how a unit's maximum power varies with changing supply voltages: it may go down in proportion--or, if the design keeps the power level constant, it may instead go up. To clarify: a maker may say his unit takes 7,200 watts at 240 volts. Now if the unit works one way, reducing the voltage by 10% (to 216 volts) might simply drop the unit's "wide-open" power output to 6,480 watts, a corresponding 10% drop. But if the unit is designed another way, so as to keep its power steady, then at 216 volts it might draw over 33 amps so as to maintain that 7,200-watt output. It is our belief that most, possibly all, residential-type units work in the first way, what we might call the "common-sense" way: less voltage, less power. But we know for a fact that at least some commercial units work the other way, so assume nothing--ask, or do your own arithmetic."

So, by this reasoning, does the sellers claim that the unit will consume 2860w @13a 220v (in his example) make more sense ? i.e. how much power the unit outputs, and thus how many amps is draws (which is obviously the issue here), is set by the voltage it is given ? The other consideration the induction hob site brings into the equation is that the power ratings of such hobs are usually fairly inaccurate and that often the hob will not be actually drawing it's full amount of watts unless it is run with all zones on full at the same time. And even then, it seems that the maximum power of a unit in watts is not always the sum of the unit's zones (i.e. 1800w and 1600w in the case of this one) added up.



I am having difficulty understanding, using this example from the induction hob site, how the appliance will draw the same amount of amps wherever it is. I don't get how that is decided.
I know I'm possibly being thick so please spell it out for me.

 

[BS3036]

I don't think you're being thick.

The nominal voltage (i.e. what we call the voltage) is 230V both here and in Germany. In practice neither country has changed their actual supply voltages from the time when the nominal voltage here was 240V and the nominal voltage in Germany was 220V.

In practice then, connecting equipment to the supply in the two different countries will make a difference to the current drawn, which may be greater or may be less, depending on the circuitry in the appliance.

However the difference is not great enough to make the 3400W in Germany reduce to 2860W here. I believe the seller is simply making up a number to reduce the power below that which will draw 13A, in order to sell his product in the UK.

If fact, it is just possible to get the drawn current down to 13A if you make the right assumtions. If the power rating of 3400W is actually what is drawn on German 220V and if the appliance design reduces its power draw in inverse proportion to the applied voltage, then by applying 240V you bring the power down to 220/240 x 3400 = 3117W.

If you then carry on and work out the current drawn at 240V you get 12.98A, a tad under 13A.

If it were me I would measure the current drawn in practice, as that is better than a lot of theorising.

http://www.maplin.co.uk/Module.aspx?ModuleNo=38343 is a good way to do this and it is currently on sale at £9.99. If you have a Maplin shop nearby it would be a way to answer the question. This unit will directly display the current drawn. You would need to fully load the hob with two pans of cold water and switch them both on at the same time, and observe the highest number of amps drawn.

Failing that, I don't think anyone can in all honesty recommend that you just ignore the problem, so sending it back would be the only thing anyone could suggest. It is a shame, because the price is very attractive.

 

[newhobgirl]

Thanks for the reply.

So, all in all I have two options;

I either send it back (the seller has been quite spikey about this and has not yet confirmed I would get a full refund despite having a fourteen day money back guarantee, ffs)

Or I get one of those doobrys from Maplins and give it a test with the evil adapter they gave me (as obviously if it shows too much current drawn I will want to send it back and I can't do that if I cut the plug off and put a three pin UK one on.)

Assuming I get one of those Maplin doobrys;
If it shows it is drawing under 13A when both zones are turned up full and to the full temp, can I assume that this will always be the case ? i.e. If that shows the current draw is under 13A today when it is going at fell pelt, it will continue to be the same ad infinitum (unless the unit malfunctions of course) ? What I really mean is, if I test it out and it shows as under 13A today, should I just assume the seller is at least partially correct and this thing (barring possible malfunctions over time that one might get with any appliance) is never going to blow a fuse unduely, set fire to my kitchen or pervert the family dog (I jest because it's doign my nut !)

 

[Steve]

The thing with a 13 amp fuse it that it could possibly take a sustained overload of 15 amps indefinitely. It is unlikely to blow. However, it may do damage to the socket and / or the plug due to them only being rated at 13 amps.

The seller is, frankly, talking out of his rear in his explanation. In a resistive appliance (ie. a light, heater etc), the power drawn is a constant, whereby the current drawn will vary in inverse proportion with the voltage. So more volts = less current. The UK voltage is probably slightly higher, but it still isn't enough to take it under 13 amps.

His explanation of 220 volts times 13 amps equaling 2800 watts is correct, however it does not have any relation to your appliance!!!! Since your appliance has a constant draw of 3400 watts! You have a lemon, unfortunately. Sorry.

I have a 100 amp supply in my house, but I could draw 150 amps indefinitely, since the 100 amp fuse does not limit the current drawn, it simply breaks when its overloaded for a sustained period. It will pass 150 amps for a long time due to its characteristics, but this could cause damage to the fuse holder and other parts due to heat damage etc.

 

[BS3036]

If it shows it is drawing under 13A when both zones are turned up full and to the full temp, can I assume that this will always be the case ? i.e. If that shows the current draw is under 13A today when it is going at fell pelt, it will continue to be the same ad infinitum (unless the unit malfunctions of course) ?

Under those circumstances, I would personally accept the risk, knowing that:
- if I had any doubts I could always bring out the power checker at any time.

- the appliance and the house wiring would be protected by the 13A fuse if the plug which by then you would have fitted

- in any case the ring final circuit is protected by the fuse or breaker in the consumer unit

However, I could not in all conscience, make a direct recommendation under these circumstances, as you can probably understand.

One failsafe possibility to consider is having a dedicated circuit added to your kitchen. Only you (or an electrician) can judge how difficult that would be.

 

[newhobgirl]

If it shows it is drawing under 13A when both zones are turned up full and to the full temp, can I assume that this will always be the case ? i.e. If that shows the current draw is under 13A today when it is going at fell pelt, it will continue to be the same ad infinitum (unless the unit malfunctions of course) ?

Under those circumstances, I would personally accept the risk, knowing that:
- if I had any doubts I could always bring out the power checker at any time.

- the appliance and the house wiring would be protected by the 13A fuse if the plug which by then you would have fitted

- in any case the ring final circuit is protected by the fuse or breaker in the consumer unit

However, I could not in all conscience, make a direct recommendation under these circumstances, as you can probably understand.

One failsafe possibility to consider is having a dedicated circuit added to your kitchen. Only you (or an electrician) can judge how difficult that would be.

Thanks again for your reply.

A dedicated cooker circuit would require a new consumer unit I am told as the current one will not support anything else, plus the obvious wiring and chasing out and whatnot. The previous owners of the house stole the slot in the consumer unit that would have been for a cooker circuit for power to an outside workshop I am also told. So it's a non starter as I don't have the money to get such a thing done.

I very much appreciate all the trouble you guys have taken to explain this thing to me. It seems that in order to make this thing remotely palatable, I'd have to cut the plug off and fit a UK three pin plug, which the seller has declined to tell me (I've asked) if that invalidates the warranty or not. And even then those who know better than I - i.e. you lot - still are not happy about recommending this lemon.
So all in all it's just proving more trouble than I really want. Wish I'd never set eyes on it !!

The seller has now emailed me and asked if I can wait until the next buyer from the UK purchases a unit and send mine directly to them, as opposed to him, and that he will refund me the purchase price plus shipping in this case. Why he wants to do it like that I don't know, but, I don't care where it goes after I send it, as long as the money comes back to me.
So, I will package it up in its box again and send it off to whoever buys it (I'd be fed up if I were the recipient though - I'd see that as well dodgy). I will buy a single portable induction plate from a reputable UK manufacturer and be sure to check it does not exceed any power requirements.

It's my birthday on monday - this was supposed to be a birthday present to myself. Epic fail ! lol.

Thankyou again folks - you have been gentle-persons and scholars all, and have been very patient with me.

 

[BS3036]

Probably the best resolution. You'll feel happier in the long run. Save your ebay feedback until you have your refund! Then you can tell the truth if you are still allowed to leave feedback after a cancelled sale. Remember he can't leave you negative feedback under the new rules.

 

[ban-all-sheds]

I haven't checked, but does anyone know if selling an appliance with a plug like that and an adapter like that complies with The Plugs and Sockets etc. (Safety) Regulations 1994 ?

And as for this:

because the supply in the UK is only 13A - the power output is 13A x 220V = 2860W
in the EU is 16A.

it's complete nonsense. Either the guy knows nothing about what he's selling or he's trying to spoof you.

What he said is like claiming that a BMW M5 sold here will only do 70mph if you put your foot to the floor because that's the speed limit.

Note that the rating plate states an unvarying power consumption of 3.4kW for the entire range of rated voltage....

 

[BS3036]

it's complete nonsense.

Of course it is, but the question is, who is going to take the trouble to do anything about when the seller is in Germany?

The last time I tried to approach Trading Standards, I found they had surrounded themselves with a web-site and no way to contact them that I could find.

 

[davelx]

The seller is, frankly, talking out of his rear in his explanation. In a resistive appliance (ie. a light, heater etc), the power drawn is a constant, whereby the current drawn will vary in inverse proportion with the voltage. So more volts = less current. The UK voltage is probably slightly higher, but it still isn't enough to take it under 13 amps.
.

NO!!!!!! In a resistive appliance the relationship between voltage, current and power is LINEAR and PROPORTIONAL (NOT inversely proportional). It requires active/switched mode power supplies to do what you suggest.

Lower volts = lower current = lower power. There may be some small non-linearity in the voltage/current graph due to the lower temperature causing the element resistance to be lower than when at full power, but the power drawn is still close to directly proportional to the applied voltage (at any useful value of voltage)

 

[newhobgirl]

The seller is, frankly, talking out of his rear in his explanation. In a resistive appliance (ie. a light, heater etc), the power drawn is a constant, whereby the current drawn will vary in inverse proportion with the voltage. So more volts = less current. The UK voltage is probably slightly higher, but it still isn't enough to take it under 13 amps.
.

NO!!!!!! In a resistive appliance the relationship between voltage, current and power is LINEAR and PROPORTIONAL (NOT inversely proportional). It requires active/switched mode power supplies to do what you suggest.

Lower volts = lower current = lower power. There may be some small non-linearity in the voltage/current graph due to the lower temperature causing the element resistance to be lower than when at full power, but the power drawn is still close to directly proportional to the applied voltage (at any useful value of voltage)

So, what does that mean to this hob then ? (being thick)

 

[aptsys]

Note that the rating plate states an unvarying power consumption of 3.4kW for the entire range of rated voltage....

And that is true with an induction hob. It doesn't work like a resistive element - if the mains voltage drops, more current will be dumped into the coil to give a constant heating power.

 

[mattylad]

You could always report them to Ebay too, if what they say is wrong 7 it is not legal to plug them in then it is an illegal transaction.
If you used paypal you could get a refund.

 

[BS3036]

newhobgirl: The possible scenario I outlined above, to bring the current below 13A, made a lot of best-case assumptions. All of these other suggestions are discussions of scenarios which involve more current, and you should not draw any hope from them. Stick to your plan.


Here's a picture for anyone interested.

(Hope the hot link isn't against site rules)

It's from this page which explains how induction hobs may be designed.

In this case it seems that the thing being controlled is CURRENT. So the power drawn would be proportional to the applied voltage, making the power draw greater here in the UK.

 

[newhobgirl]

newhobgirl: The possible scenario I outlined above, to bring the current below 13A, made a lot of best-case assumptions. All of these other suggestions are discussions of scenarios which involve more current, and you should not draw any hope from them. Stick to your plan.

Thankyou for putting that in terms I get. That's all I need to know about it, the rest can go over my head then.

I shall depart this thread forthwith, to save me asking anymore hopeful questions !