simonsi

Nah you are off there, not enough heat being generated by those things to warrant 10A draw, do you feel like you have a 2.4Kw electric fire on in the room when you watch TV? Probably 2-3A max.

simonsi

Not sure why you distinguish between 240v and 230v, most mains supplies vary 10v either way (usually low though), due to generation/consumer load balancing on the grid.

The original concern created was over bringing UK appliances over. Specifically a UK 3Kw electric fire can and will overload a NZ 10A socket on its own. Nothing else is likely to do that using modern appliances even through a 4-way.

Pom_Chch

We still have our Tesco 5 quid kettle going strong after 4 years! My OH has a clock radio that he's had for about 30 years

escapedtonz

....because it 's habit, because electricity has been my job/passion for the past 29 years and because 230v is the statutory nominal single phase domestic voltage in NZ (and the UK for that matter). It was 240v many years ago, but industry decided it wanted to joint the path others countries/continents were taking so it was dropped.
All voltages vary due to the natural rise and fall of the load curve during the day ......nothing whatsoever to do with generation. It is all do do with load and any voltage spikes are due to faults.
The higher the voltage, the higher % error is allowed before those statutory voltage limits are breached which forces a report to the EA....220kV AC down to 50kV AC is +/- 10%, 33kV AC and below is +/- 5%, so yes single phase domestic supplies can vary as far as 218.5v low and 241.5v high in NZ and yes it is better to be low as low volts doesn't cause insulation failure or fires whereas high volts does.
....and load balancing ? That's to do with computers, IT network traffic and servers, not electricity
I can assure you, I don't balance load on the grid. What I do do is ensure sufficient offered generation is available and dispatched to meet at, just below or just above the ever changing minute by minute load in each Island at lowest economic cost to maintain the frequency at, or as near as damn it to 50.00Hz and time error to within +/- 5.00 seconds, whilst also managing the ever changing reactive component of the load and grid to maintain statutory volts within limits.

I agree that a 3kw heating appliance from overseas working at its maximum output would in fact overload a standard NZ 10A rated radial feed
Amps=rated power/volts so A=3000/230 so A=13.043 which is bang on the money for the UK, but too high for NZ.
The onus is on the home owner to abide by the rules and regulations of the NZ Electrical Code Of Practice Homeowner to get it right and not overload their domestic system by plugging in such a device.
Not saying that happens as I'd bet the thought wouldn't even cross most peoples minds, but it is the reason why you cannot purchase a plug in heater any bigger than 2.4kw in NZ.

simonsi

Well done, you win the award for the most unecessarily pedantic post. As I said, a UK 3Kw fire can overload a NZ socket and the difference between 230 and 240 when referring to mains voltage in an internet forum isnt worth a damn. Or were you just showing off? Pretty sure in there somewhere you agree that you balance generation against load to keep the supply within limits too. Ho hum, a face to face discussion with you down the pub must be exciting...

SSky

In about June 2004 when we first moved into our first NZ home which was only a 4 yr old property we plugged in our UK fake electric coal fire (with real coals on top) and it melted it's plug and shorted out the electrics. We didn't understand why it had done this at the time as we thought NZ was the same volt as the UK. i loved that fire lol, it was purely for ornamental purposes and I still have it now but it's up in the loft in two plastic bin bags cos I loved the look of it but it but I never trusted it and this thread kind of has explained why it melted our plug.

escapedtonz

Thanks I try my best. I'll place it with my many others.
Didn't intend on being pedantic but your argument was flawed so hey ho I came to everyone's rescue ;-)
Nah I wasn't showing off, just forcing across my superior knowledge.....WAIT, that's the same Damn!
...and it's impossible to balance load and generation as load is as difficult to forecast as the weather and ever changing. All one can do is take a calculated guess.

Now now simonsi. Play nice with the other children and act your age!

Pulaski

His argument wasn't flawed, it was completely correct, and the difference you identified was immaterial to the point being discussed (a voltage difference of 4% doesn't change the current by enough to come to a different conclusion), so I would agree with Simonsi when he said you were being pedantic.

simonsi

As you can see from SSky's post, this can and does happen and actually is dangerous, kind of important that people can see that amongst the showoff unecessary "science" you brought to the thread.

Clappy

Well, there you go.

I always believed that mains electricity in the UK was 240 Volts.

It was 240 Volts when I was a child and I was completely unaware that there had been a changeover to 230±10 which happened while I was an adult.

I would not know about that if I hadn't followed up some of the posts from this forum.

escapedtonz

Hold on a minute....doesn't the difference I identified, which you state above, make simonski's argument not completely correct ?
So you have just completely contradicted yourself.

Yes, the difference in current draw between 230v and 240v is small, however I wouldn't say completely immaterial as a lower nominal voltage makes this scenario worse.......lower volts means higher current.
The argument was quoting a nominal voltage of 240v which is incorrect and the reason why I voiced my opinion, of which I am entitled since it's a public forum and if I posted something not 100% accurate I'd expect the forum police would also catch me out.

escapedtonz

Pulaski hinted at the science early in the thread.
The equation I used was the same, just explained further and as for the rest of the "showoff unnecessary science" as you put it, you asked why I posted what I did so you received an answer.

Pulaski

See below ("On the other hand ...."), this anomaly occured because you specified 3Kw as the constant, when in fact the resistance is the constant.
Go look at the meaning of "immaterial" - I even hyperlinked it for you - in short 230v will push a dangerous current through a 3Kw appliance in NZ, 240v is slightly worse. If the difference you pointed out made a difference between dangerous and not dangerous, or even marginally dangerous v dangerous then the difference certainly would have been material, but when anything over 10A is dangerous and the difference between 230v and 240v is that one has a current draw of 12.5A and the other has a current draw of 13.04A (these number are upside down, because the power produced is not the constant in this scenario), which I would contend makes the difference immaterial, because both are seriously dangerous.

On the other hand I could poke a hole in your entire calculation because you have taken the power rating as a constant when in fact the constant is resistance in this scenario (the behaviour of one specific appliance), where "voltage = current x resistance" or "resistance = voltage/ current", so if, as you calculated the current at 230v = 13.043A, then the current at 240v = 13.61A.
Indeed they would.

wez130

Oh jeez, what did i start here?

(sorry OP).

escapedtonz

Immaterial, but UK limits on voltage are +10% and -6%