Hi.

I have been asked to install Duplex Receptacle Outlets (US style Socket outlets) in a house in Britain during a refurb.

I would appreciate any answers with regards to the following...

Will they run on a normal Ring Main, like our twin sockets do?

Will they be ok on 230v ac?

Where can I get hold of them and the appropriate back boxes?

Many thanks to anyone that can help.

Regards

I do not think that this is a very good idea, but if you must,

USA style outlets should on no account be connected to UK ring final circuit.

On no account should they be connected ANY UK circuit that is connected to our standard 230/240 volt supply.
Anyone seeing such an outlet could reasonably assume that it was 120 volts as used in the USA.

Such outlets should be connected to a suitable transformer with a 120 volt output.and be on a fuse or circuit breaker not exceeding 20 amps.

A building site type transformer is not ideall for two reasons, firstly the output is 110 volts nominal and not 120, and secondly the mid point is earthed.
A 120 volt supply, with one wire being an earthed neutral is required.

The frequency will still be wrong, it is 50 cycles here and 60 in the USA.
Most appliances dont care, but some will, especialy induction motors and copper/iron lamp ballasts.

AFAIR Crabtree sell USA outlets that fit UK style mounting boxes, but they reluctant to sell them in the UK unless satisfied that you are exporting them.

You can buy the sockets from RS
USA outlet

I bought loads some years ago, but thought that they were discontinued.
They fit standard UK back boxes.

I would ask your client why they want them, and what voltage they want.
I would be very wary of fitting them for a number of reasons
1) They are not rated for UK voltage. remember a 240v supply plus 6% can give a peak voltage of 350v.
2) UK rings are fused at 30A but our plug tops have a fuse. Anything connected using a US style plug would be fused at 30A!
If the customer definetly wants them I would fit a step down transformer fed from a fused spur or its own way on the DB and then run radial circuits to the sockets. A 240/110 site transformer would do the trick but you may have to change it from centre tap earth to one of the outers earthed. In addition you will need overcurrent protection and a RCD on the outlet.
I belive RS may do US sockets, failing that there must be a company on the web that does mail order.

I must agree with broadgage here. As a matter of course, I would not install them due to the voltage / frequency issues already mentioned. I have used them twice, where I needed a plug & socket arrangement for computer equipment that I was running off 48v dc. It seemed more sensible for me to use a 48/120v inverter than a 48v/230v inverter, so I needed a 120v plug & socket that would not be confused with anything else. I used a three-pin version, which MK do in their white "logic" range. As broadgage, I also had the questions about which country it would be used in.

Regards,

Alan.

If these are to be installed, clearly label them as being 120 volts, 50 cycles.

USA style outlets have become an unofficial semi-standard for 12 volts DC in off grid homes, or for standby purposes.
I have wired two homes thus, and I understand that the idea has been widely copied.
To use these outlets for 12 volts would be foolhardy in the USA but is fairly sensible here, as they are not widely used for any other voltage.

There is nothing else readily available, neat looking and affordable for 12 volt lighting and small power outlets in off grid homes.

Complete madness to use USA outlets for 12v DC. Trouble is there is no standard. Caravans can be fitted with USA style, 3 pin 2A mains type, 3 pin 5A mains type or fag lighter type. In Australia there is a standard low voltage plug using 2 flat blades at right angles, perfect and polarised.

Incidentally can someone explain what the problem is with using a site transformer and leaving the earthed centre tap in place?

I can not agree that it is madness to use USA type outlets for 12 volts DC in the UK.
The practice is widespread and the outlets are not widely used for any other voltage in the UK.
The various 2 amp and 5 amp outlets listed above are of insuficient capacity for loads such as laptops, electric blankets, slow cookers, kettles, or even high power lamps.

And anyway it is bit late to alter it as the practice is widespread, especialy for off grid homes rather than caravans.
The last off grid home that I did used USA outlets throughout for 12 volts DC together with round pin 15 amp outlets for 24 volts DC.

In the brewing industry, the use of 2 pin USA outlets is widespread for 12 volts AC from an isolating transformer, to supply the small lamps used in beer taps.

When I was with DBC last year this was an issue that was raised after a planning application was rejected, basically a wealthy client bought a large derelict property on the River Dart as a country retreat and somewhere to park his catamaran, amongst other things he wanted US style sockets all around the house anyway things went badly wrong between the client, his solicitor and the LA planning department who had refused the application so that resulted in three of us looking into the issue as a panel on behalf of the department, I wont comment on the dispute and the outcome as this is matter for the LA concerned and the client, but I will comment on the technical and legal issues that were raised at the time.

1. These socket outlets are not deemed fit for use on UK 230V earthing systems, they are a departure from the national wiring rules and subsequently the knock on effect means they do not comply with the national building regulations, there is no facility to certificate them fit for use under UK standards, this also compromises the issuance of a building regulations compliance certificate.

2. This draws into the arguement the Plugs and Sockets Regulations, these socket outlets should have on them, on the data sheet, on the packaging the words "NOT FOR UK USE" or "NON UK" but as we all know they come from spurious places so this might not be so.

3. As pointed out above by broadgage they can be used via a appropriate transformer but this brings into play another technical arguement, the national wiring rules (BS7671) only cover an installation as far as the electrical outlet, this could be a socket outlet, fused spur or lighting point, from there on other standards apply, the outlet that supplies the transformer would be the limit of BS7671 and technically the transformer and its sockets would be regarded as an appliance.

As far as the law is concerned it is not illegal to fit these socket outlets and the owner or his contractor can do this but must accept the fact that they cannot be certified as safe or in conformity with national wiring and building standards, so should an incident occur then the client must accept the consequences where insurances such as life/building/fire etc, could be compromised.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------

Edited: 29 July 2012 at 05:32 PM by rocknroll