Low voltage lighting in 18th edition?

[ARW]

They also have an on site electrician.

[Harry Bloomfield]

[e-mail] presented the following explanation :

I have seen lots of filament lamps sold in the UK, but intended for

230v. Aldi sold some a few years ago and I bought some from an ebay seller in the UK. They don't survive long.

Likewise, a friend bought some LED's specced for 230v which soon died. Now I always check the intended voltage rather than assume they are correct.

[Harry Bloomfield]

Dave Plowman (News) expressed precisely :

Not at all, it was a joke, its just that so many now believe we are on a UK local voltage of 230v.

[Scott]

Okay, thanks very much.

[Harry Bloomfield]

Dave Plowman (News) submitted this idea :

You obviously misunderstand how RCD's operate..

[Harry Bloomfield]

Dave Plowman (News) formulated the question :

Which means that if there is no leakage to earth, contact just across L to N could well mean no leakage to earth, that it would not operate.

[Harry Bloomfield]

Roger Hayter used his keyboard to write :

In a home environment there tends not to be not that many good paths to earth. Carpets, upholstery, wood furniture and wood floors are all pretty good insulators when dry - not much chance there of an RCD tripping.

[Harry Bloomfield]

Dave Liquorice explained :

My first shock was around that age, from the grill of an electric cooker, trying to light a match. A modern toaster also has bare elements, but perhaps less easy to make contact with.

[Dave Liquorice]

It may have ben coincidence but when the local primary substation was being fed via the 11 kV backup circuit and our overnight voltage sat at 253 or a shade over for 6 hours or so. Two LED bulbs that are on

24/7 failed... Failure mode was the LED chips falling off the board/heatsink they were mounted on.

[Dave Liquorice]

If the resistance to "earth" is less than 7.6 k ohms a 30 mA RCD will trip. In a modern home with lots of kit with SMPSUs and their associated mains filters all leaking the allowed mA a nominal 30 mA RCD may only need an extra 20 mA or less to trip. 230 V will push 20 mA through 11.5 k ohms.

[Dave Liquorice]

Who earnt his money at Sunderland's "Stadium of Light" not so long ago. Ordinary live to world (but not the UK) EPL fixture, so lights are allowed to go out but should come back on again within 10 minutes, ie about how long they have to cool before being restruck (they are "arc lamps" most variations won't restrike when hot).

[Roger Hayter]

But will *not* be caused by connecting a person between live and neutral.

[tabbypurr]

I bet we're all curious where else you think the current imbalance goes.

NT

[Bob Eager]

Unless said person also has at least a partial path to earth.

[Roger Hayter]

If I am specifying a circuit I would generally be implying no connections other than those I specified. But your point is a good one, and made nearby in this thread.

[Dave Plowman (News)]

A whole house RCD can trip on a neutral fault in a circuit with a single pole MCB to that circuit switched off - so no connection to the line at all.

[Johnny B Good]

I was wondering when that particular *fact* would finally be mentioned. :-)

If you care to take a close look at the marked voltage rating on virtually *any* UK mains voltage tungsten filament incandescent lamp, you will see the voltage specified as 240v and *not* 230v (likewise on the continent where 220v mains is in common use you'll see lamps rated for

220v, *not* the harmonised 230v).

If proof was needed that the 'harmonised 230v' is voltage in name only, the extreme sensitivity of the tungsten filament incandescent lamp to voltage variations' on both lamp life and efficacy is all the proof you need that your actual mains supply voltage is what is marked on the GLS tungsten filament lamps on sale in your local shops.

If you do happen to spot a rogue 230v example, check out a few of the alternative wattage rated lamps on the shop shelves for comparison before assuming that your local mains supply has actually been reduced in reality and not merely in name.

[Johnny B Good]

Incandescent lamps have always been marked with the exact voltage they've been designed to operate from in order to achieve the specified average life (1000 hours in the UK and 750 hours in the USA) and a specified Lumens output. Just about everything else will tolerate the wider voltage range without undue hindrance to both service life and performance.

All that has happened is that the minimum and maximum voltage limits have been centred on the notional 'harmonised 230v' leaving the existing

240v UK and 220v European supplies to carry on operating at 240 and 220 volts respectively but maintained within new tolerance limits that are identical regardless of the target 240 and 220 volt supply voltages in actual use.

Unless there is a sudden policy decision to revert our 240v UK tolerance limits back to pre-harmonisation limits, the manufacturers can carry on selling "230v" rated appliances without any re-labelling costs. In the unlikely event that a choice is made to revert back to pre-harmonisation limits, it's very likely to be done with plenty of advance notice to the manufacturers who can then introduce the new labelling as and when they retool for new models of electrical goods, neatly avoiding the minor expense in relabelling existing product.

It's very likely that both the UK and the continent will carry on working to the harmonisation tolerances with the UK still using 240v filament lamps leaving our continental cousins to carry on using 220v filament lamps.

[tabbypurr]

Yes... though that is seldom what happens.

NT

[Huge]

[Hollow laughter]