16th Edition

[Tubs]

Just browsing,

I know we are not electrians but
thought this could be of some use.

http://www.tlc-direct.co.uk/Book/1.1.htm

Steve

[goosegreen]

Re: 16th Edition

Thanks Tubs
Have saved the site, Lot of usefull stuff

Goosegreen

[Penguin45]

Re: 16th Edition

Read the paragraphs “Notes on Supply Voltage Level”. I wonder if this why we have high failure levels of cheap electronics? Not designed to cope with the extra load in the UK.

Just a thought,
Chris.

[woz]

Re: 16th Edition

Thats exactly why we have premature oven element failures

all European appliances are rated at 220-230 👿

Woz

[kwatt]

And long may it continue… that one I’m not going to complain about. 😉

K.

[woz]

Re: 16th Edition

It’s only a matter of time and a few hundred million quids that the numbskulls at the electricity board will find the reostat though to adjust the voltage 😆

There was a lot of tests done regarding the voltage difference.

2 light bulbs were tested one at 230 and 0ne at 240.
the one at 230 was approximately 40 degrees hotter

Possible fire hazzard if you ask me 😯

[Phidom]

Re: 16th Edition

I don’t have my meter calibrated but I frequently read mains voltages around 250 volts. They are allowed quite a big tolerance on the voltage, only the 50 Hz has to be kept spot-on.

[Kenny]

Re: 16th Edition

Phidom
The allowed voltage variation in the UK is +- 6 percent (240 volts is the root mean square value (avarage))

You are correct that supply authority has to maintain the 50Hz frequency but this is to do with supply and tranmission concerns rather than the end user.

The voltage is of concern to us becouse of the power that a unit will use is constant. Power is calculated from Volts x Amps = Watts

So if you decrease the voltage the machine will draw a higher current. to run at the required power rating. and vice verca

[electrofix]

Re: 16th Edition

you will not get a pure resistive load to draw more current if you lower the voltage if you lower volts you lower current in proportion basic ohms law

at the moment the supply can vary -6{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} +10{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} which at a nominal 230v tops out at 253v rms

[RS]

This topic is quite interesting in as far as the comments go and I find the fact of using RMS to specify the voltage delivered quite laughable. Put on a scope you will see that the peak to peak voltage comes out at around 260 to 300 volts now this is not particularly important in modern electronics where regulators are used in all areas but it does show up in the lifetime of a domestic bulb, heating elements and other such items.

The comment about the differing voltage of the two light bulbs and the heat they produced is just plain Ohm’s law that we all should be aware of in this trade, but I have wondered for years if the domestic appliance manufacturers have put enough safety margin when designing the appliances and could this be a factor in the early demise of such things as timers and control boards.

If you look at a lot of the small appliances these days you will find many are rated at 220/230V which if we consider the peak to peak voltage, is nowhere near suitable for our supply in this country

Richard Scanlon Snr

[Tubs]

Re: 16th Edition

Hi all

I have an interesting article on light bulbs, I will see if I can dig it out

Steve

[Author]

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