PowerSwitch

[BritDownUnder]

[fuzzy]

No 3 phase in UK homes. AFAIK it's not allowed.

[adam2]

[vtsnowedin]

I can't imagine why anyone would restrict three phase. It has to be installed properly but that is true of single phase arrangements.

[adam2]

[fuzzy]

[adam2]

Nothing under current UK regulations prohibits the use of 3 phase supplies for general domestic purposes including general purpose lighting and power circuits.
As an example, nothing prohibits the cooker on one phase, the 13 amp sockets in the same room being on another phase, and the lights on the third phase.

The requirement for lamps and single phase outlets to be on the same phase if within 2meters went out many years ago, in the 1960s I think, but many still believe this to be a requirement.

The requirements for lamps in the same room or area to be on the same phase (or the same pole of a DC system) was arguably sensible back in the days of un-earthed lighting circuits, brass lamp holders and light switches, and perished twin twisted rubber insulated lamp flex.
I would not have fancied 415 or 480 volts between two un-earthed brass light switches.
For many years now, lighting circuits have had to be earthed, indeed the requirement to earth lighting circuits MAY have come in at the same time that the regulation requiring separation between phases/poles was abolished.
Also the introduction of fluorescent lighting in the 1950s meant that splitting factory lighting over 3 phases was recommended to avoid stroboscopic effects with moving machinery. Try getting light from fluorescent lamps on each phase to each part of a factory, AND keeping the lamps on different phases 2 meters apart !
_________________
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"

[fuzzy]

Thanks for the info, you have a lot of knowledge! In this age of comms and many low powered appliances, different phases seems a recipe for hums and noise. I think I read that about 30% of houses still have lighting without earth [mine included]. A recent bathroom move required a very laid back electrician.

[BritDownUnder]

The excuse given in Australia by power companies to insist on 3 phase inverters for solar PV installations above 5 kW is otherwise one of the 3 phases of the local distribution electricity supply will get unbalanced if the inverter outputs only a single phase. Having one phase feeding in at peak solar generation and minimal usage around midday when few people are at home and the other two non PV phases supplying current would probably screw things up for the local transformer.

I suppose the power grid is much more spread out in Australia than the UK.

I have three phases sent to my house but I only use one phase as you pay more standing charge for three phases and I have no large motor loads that need three phase at my current address.

I have a colleague with three phase in his house and has lights on one and ring mains on another and the stove on the third phase. In a typical Australian house the only device using all three phases would be a large ducted air conditioning unit. Another colleague was forced to get three phase by virtue of his 6kW grid tied solar PV array and uses only one of his three phases for everything.
_________________
G'Day cobber!

[vtsnowedin]

[adam2]

If the light(s) in a bathroom are of "all insulated" construction, and the switch is plastic and either outside the bathroom or is operated by a pull cord, then an earth wire serves no purpose, but is a regulatory requirement.

It is IMHO a reasonable requirement to allow for the future installation of a metal light fitting that probably DOES need earthing.

Standard mains voltage outlets were for many years strictly prohibited in UK bathrooms. They are now allowed under certain conditions, but must firstly be earthed, and secondly must be protected by an RCD (UK term for what in America is called a GFCI)

All general purpose mains voltage outlets in the UK MUST be earthed, non earthed , 2 pin outlets "went out with the war"
_________________
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"

[Mr. Fox]

Older installations with no CPC (earth wire) on the lighting circuits can be brought to a level of conformity with current regs by ensuring all fixtures and fittings are class II (double insulated)...

When I've come across them (and rewiring wasn't an option), we've used bayonet pendants with the pins that disconnect when no lamp is inserted, 'Nexus' range switches (that have plastic covers for the screws), etc.

Not ideal, but the regs aren't retrospective, so sometimes you've just got to do what you can... what is 'practicable', in regs-speak.

[clv101]

[vtsnowedin]

[fuzzy]