Electricty supply

[esselte]

Good evening all,does anyone know what the voltage spec and tolerance is for the domestic electricity supply (in the UK).My lights at home seem quite dim usually.Checked the voltage and it is arond 215-220.Thanks .

[apache]

Should be 240V 50Hz

[byff]

Voltage is fine - the brightness of your bulbs is determined by the wattage. 15W is quite dim, 100W is very bright. Look to see what wattage is stamped on your bulb.

[esselte]

byff said:

Voltage is fine - the brightness of your bulbs is determined by the wattage. 15W is quite dim, 100W is very bright. Look to see what wattage is stamped on your bulb.

Yes I know that ,just recently they have gone dimmer.Sorry if I didn't explain it very well.

[dilbert]

Voltage spec is quite wide. I should think 215 is about the lowest, +/- 25 would seem reasonable at 10%.

Frequency and phase spec is as tight as a ducks posterior.

Edited to add;

If you phone them up, you could ask them to put on another knob of coal!

>> Edited by dilbert on Sunday 11th September 18:44

[esselte]

dilbert said:

Voltage spec is quite wide. I should think 215 is about the lowest, +/- 25 would seem reasonable at 10%. Frequency and phase spec is as tight as a ducks posterior. Edited to add; If you phone them up, you could ask them to put on another knob of coal! >> Edited by dilbert on Sunday 11th September 18:44

Thanks Dilbert,just measured again and it's 215..Would freq and phase affect the lights?I've no way of measuring the frequency anyway,so I suppose I'll be on the phone tomorrow and see why they're not feeding the hamster.

[dilbert]

If they get the phase or frequency wrong, big things start moving. Generator sets fly across turbine houses, pylons vibrate, all manner of nasties start happening. You'd know about that, if it happened.

Your lights will dim if the line voltage falls.

P=V^2/R

The R(esistance) of your lamp doesn't change, so power reduces/increases with the square of voltage.

Power is quoted, for a given 240V, if it's a mains bulb.

>> Edited by dilbert on Sunday 11th September 19:11

[esselte]

dilbert said:

If they get the pase or frequency wrong, big things start moving. Generator sets fly across turbine houses, pylons vibrate, all manner of nasties start happening. You'd know about that if it happened. Your lights will dim if the line voltage falls. P=V^2/R The R(esistance) of your lamp doesn't change, so power reduces with the square of voltage. Power is quoted, for a given 240V, if it's a mains bulb.

Yeah I think it's a voltage issue.Our supply is via an overhead cable from a transformer "on a pole".So may be an issue there. Ho Hum.

[DrDeAtH]

the mains electricity supply should be 240 +/- 4%
that is the allowances that are set out in the electrical regs.

[dilbert]

Sounds like the hamster died then. We're now running on the backup army of fleas.

[tvrgit]

where are you measuring the voltage? at the light socket?

could it be deteriorated wires / connections causing resistance?

[planetdave]

Excuse me for butting in with my pathetic lack of knowledge.......

Was there not a 'harmonisation' with europe which means that average voltage has dropped to 230?

Also, being an average, it is higher off peak than @ peak due to the lower loading?


Off to check parachute

[Size Nine Elm]

planetdave said:

Excuse me for butting in with my pathetic lack of knowledge....... Was there not a 'harmonisation' with europe which means that average voltage has dropped to 230? Also, being an average, it is higher off peak than @ peak due to the lower loading? Off to check parachute

IIRC you tend to get brownouts (voltage drops) during ad breaks on the soaps because everyone puts the kettle on at the same time - a power requirement about the same as supplying Birmingham.

[driftwood]

anybody nearby using a welder? our neighbour used to weld and evertime he did, our lights/microwave/oven etc., took a back seat.

[Pies]

UK supply 230 V +10% -6%

[monkeyhanger]

planetdave said:

Excuse me for butting in with my pathetic lack of knowledge....... Was there not a 'harmonisation' with europe which means that average voltage has dropped to 230? Also, being an average, it is higher off peak than @ peak due to the lower loading? Off to check parachute

Those are the "official" figures....but no-one will ever pay for all the transformers to be changed so we get a steady 230V

It generally ranges from anywhere between 220 and 250V in practice and most appliances will happily run on that.

>> Edited by monkeyhanger on Sunday 11th September 20:14

[Pigeon]

Pies said:

UK supply 230 V +10% -6%

...which works out as 216 to 253 volts. So unfortunately, you're just within spec. I take it you live out in the sticks somewhere?

The tolerance band sucks really... +10%/-6% on voltage works out as +21%/-12% on power... and -68%/+110% on incandescent bulb life.

[scared but happy]

Voltage can vary all over the place. We are at the end of the line here and I have measured 190volts! Thank god for switch mode PSU's on computers.
The only thing by law is the frequency that MUST be 50Hz and I think they do a 'catchup' over night for extended seconds type thingy?

[Pigeon]

Yeah, the short-term frequency spec is something like +/-0.5%. It drops a bit at times of high load and then runs a bit faster at night to allow mains-synchronised clocks to catch up. Over 24 hours it always works out as exactly 50Hz.

[GreenV8S]

The nominal 240 Volts is a peak value isn't it? Your meter would probably be measuring RMS which is obviously lower.