Installing Shaver Socket

[Vir Campestris]

I'm not. We've just sold a house without, and bought one that didn't (has now, total rewire).

Andy

[Vir Campestris]

It's a transformer, with 1:1 ratio of turns between input and output.

It doesn't need regulation. It's inherent in the ways transformers work.

Andy

[fred]

It's a term related to the variation of a transformer's output voltage with load:

[Uncle Peter]

I thought all the namby pamby health and softies had declared they got fitted to all new builds and all rewires?

[Roland Perry]

In message , at 18:48:41 on Tue, 31 Dec 2013, Uncle Peter remarked:

I've just measured my shaver socket in the bathroom and it's giving out

274v [or 128v], which doesn't change if I plug in an unloaded toothbrush charger (which is rated at 220-240v, 1W).

Mains voltage here this morning is 242

[Uncle Peter]

Near enough. 220,230,240, I assume the 110 has the same options.

Why on earth is it changing the mains voltage instead of simply putting it straight through? Isolating transformer? If so why not 1:1 windings? Do they include a shitty transformer and expect it to lose some voltage? I think fully loaded transformers are meant to lose 10%. They should just connect it straight to mains and have a sensitive fuse or breaker included, or ask that you do so.

[Roland Perry]

In message , at 11:40:59 on Wed, 1 Jan 2014, Uncle Peter remarked:

Mine is marked 110/240v on the outputs. I don't know what make it is.

The isolation is a safety requirement.

Just a small transformer.

That'll depend a great deal on its size and specification.

Shocking!

[ARW]

Which begs the question - Why did the nominal voltage in the UK drop from

240V to 230V but the second output on a shaver point rise from 110V to 115V?

[Roland Perry]

In message , at 12:37:04 on Wed, 1 Jan 2014, ARW remarked:

In order to be compatible with the mainland.

Perhaps the neatness of a 2:1 ratio appealed?

[ARW]

That was not a question:-) And which mainland are you refering to:-)?

All I can think of is that by making the second voltage a nominal 115V instead of 110V then the shaver point is compatable with the 230V +10%/-6% new fangled electricity we now use instead of the 240v +/- 6% good old fashioned electricity we used to use.

So if you do have 216V at the house (the lowest value now allowed) then the

115 output will not drop below 110V on the secondary windings.

[Roland Perry]

In message , at 13:12:06 on Wed, 1 Jan 2014, ARW remarked:

But 6% lower than 115v is 103v

[chris French]

In message , Uncle Peter writes

most houses are not new, nor have had a rewire in say the last 15 years or so.

This house only got one about 3 years ago when I repalced the CU

[ARW]

Trust me. It's not:-)

[Vir Campestris]

Yes, that's true.

However why do you think every house is either a new build or re-wired since the regulations changed to require RCDs?

Incidentally one of the reasons why the "new" place needed a re-wire was the rubber insulated wiring running through the thatch. How long do you think that's been there?

Andy

[Vir Campestris]

You might want to check your calculations.

Andy

[Uncle Peter]

I've got just fuses, but I know nobody else with them, and am often asked why I don't replace them. It seems a lot of folk actually replace the consumer unit just to get circuit breakers.

[Uncle Peter]

Maybe some old stone cottages still have fuses, but even dingy council flats have circuit breakers.

[Uncle Peter]

I get precisely 240V here and at my last house. I don't know why people say it's 230 because I've never seen 230 anywhere.

[Roland Perry]

In message , at 14:44:09 on Wed, 1 Jan 2014, ARW remarked:

108v then. (I must have hit 115 x .9 rather than x.94 in error).

[Uncle Peter]

Which provides too much voltage to equipment, how stupid. This is a shaver socket above eye level, not a piece of equipment on a worksite which might get drowned in water.

Why are you shocked? Is the lightbulb in your bathroom isolated? That's just as likely to get sloshed with water as a shaving light.