lights go dim when kettle switches on

[Dave Fawthrop]

|!The Wanderer wrote: |!> Ben, you've had two or three people who either work in or used to work in |!> the supply industry tell you to contact your local distribution company, |!> because in their opinion it's a problem with the distribution network. |! |!I'm away from home at the moment, but I would be interested to measure |!the voltage drop before potentially incurring expense (is there a charge |!for the distribution company having a look?). I'm expecting the drop to |!be quite significant based on the amount of dimming, but what sort of |!figure would be acceptable?

IIRC the limits are 220 V + 10% - 6%. No idea what the voltage *drop* on load should be. but measure it anyway so that you know what you are talking about.

Beware the accuracy of your meter. Allow for that in measurements.

[Stephen Dawson]

With the greatest of respect, if you feel you are too tired to give advice, then refrain, becuase you may give the wrong advice.

[<me9]

230 shirley, for euro harmonisation. Continentals are -10% +6% so are still actually 220 as to our actual 240.

[Huge]

With the greatest of respect, I fear you are confusing Usenet with Real Life.

[John Rumm]

Some of us do try to give the right advice, even when on usenet!

[John Rumm]

Depends on the motor type... for a universal motor this is certainly true. For an induction motor the speed is fixed (by mains frequency and and a certain percentage of slip). So if you place it under full load at reduced voltage it will attempt to maintain the same mechanical output, so it will have to draw more current to compensate.

How much of a problem this is will depend on the magnitude of the drop. A supply of 210V is unlikely to cause a problem, but falling to 170V say might.

(I have a friend who managed to get payment for a new freezer out of his electricity supplier, after it got very upset with the 110V or so the supplied his property with for a couple of hours)

[The Wanderer]

No, and don't let them try to tell you otherwise. You tell them you are experiencing flickering lights, which get worse when you switch on any significant load. You also tell them that the whole installation is affected, given that you have the annexe on a separate CU.

The statutory voltage must be within the limits 230v +10% -6%. I'll let you do the maths!

There are also design criteria which I'm afraid I just can't remember for the reasonable amount of flicker or dimming that can be seen on the lights because of loads coming on. Steve Dawson or Colin Wilson may be able to come up with the actual figure.

Note that this dimming or flicker may not necessarily have to take the supply voltage outside the statutory limits; it is (or was[1]) the step change in supply voltage perceptible as dimming or flickering on the lights. F'rinstance, you might have an incoming no-load supply of 250v, but this could drop to 220v with load, which results in a step change of 30v, IYSWIM. Like I said, I just can't remember the percentage figures, so treat my example as just that, an example.

[1] I say 'was' because in this post privatisation era, the standards don't seem to be enforced as rigorously as they were pre privatisation.....

[The Wanderer]

Depends on the conductor size. It could quite easily be two or three megawatts.

Diversity is a wonderful thing! Helps the companies minimise their costs. Design criteria can range from 1kva upto 5 or 6kva per dwelling, and transformers can easily withstand shortish periods of overload. Certainly not unusual for a 100kva transformer to feed 50 to 60 houses, particularly if they're in a rural location and not too many gin palaces scattered around.

[The Natural Philosopher]

Its the tractor welders and cow milking machinery that gets you in that case.

My house is FUSED for 25KVA...and I am the only one on the transformer..

[Stephen Dawson]

It used to make me chuckle the SS stood for sub-standard, and these were the most accurate analogue meters availible. I used to use japanese make, yokogawa for spot tesing, these cost about £800 each.. We then changed from paper chart recoring meters, to a unit called a Telog Linecorder, which was a pc based system and the cost went to about £3500, per unit including all the leads.

We used to be able to tell from the results which side of the connection the fault was.

[meow2222]

I think someone needs to get real. All of us overlook something at times, respond when tired, miss something etc. I've done it a few times the last few days. To expect perfection from others is not realistic, to believe in one's own perfection is equally unrealistic, and to draw the unwarranted conclusions you did above from a simple mistake does seem rash.

If I'm wrong about that, then let me know when your record is found to be free of any error or omission.

What is it about human beings that they always want to degenerate into ego nonsense instead of addressing the question.

NT

[Frank Erskine]

How can "those" be "me"?

"i.e." means "that is" - perhaps you mean "e.g." meaning "for example"...

Anyway, why "Stand back from this"? Did you gain your experience by standing back?

;-)

[The Wanderer]

Perhaps you should first ask yourself 'Have I understood what the other guy was saying? Have I said what I mean? Have I meant what I said?' before hitting the send button.

So are you saying that incorrect or misleading advice shouldn't be challenged? Especially by posters who have worked in and have considerable experience in the particular field under discussion.

Of course, the other way of looking at this is there are times when it is better to say nothing, when one risks contributing nothing of substance to the thread.

Or could it be that some posters' egos require that they just have to throw in their two pennyworth.

Or they feel the need to defend themselves because their comments aren't really germane to the discussion, they've been more than adequately covered by other posters' comments earlier in the thread, or they're challenged on the accuracy or relevance of what they've said.

[The Wanderer]

Ah, Yokogawa. I just *couldn't* remember the make, only that it was Japanese, and with a heavily damped movement that used to swing somewhat lazily to its reading.

Dataloggers were only just becoming widespread when I left the industry in

1993, and I'd been away from matters operational anyway for a couple of years prior to that - preparation and subsequent auditting of company capital budgets! Mind you, it was nice for a couple of years after I left to be able to say I'd prepared a company budget of about £130m.

[meow2222]

lifes too short. This is the kind of stuff I was talking about.

NT

[Stephen Dawson]

Hi Ben, i am interested to know what the problem was.