# same but different.



## frank (Feb 6, 2007)

A few pointers to Residential wiring here in the UK. two in particular. Sockets and lighting.

Lighting is usually via radial circuit. The same as the US I think. But loops are made at the ceiling appliance as shown,












Connection as shown here too.











Sockets on next link


----------



## frank (Feb 6, 2007)

*sockets continued.*

Socket circuits would normally be in the form of a ring circuit.Radials would not be used except for dedicated appliances and equipment.












































Cable types on next link


----------



## frank (Feb 6, 2007)

*cable types continued.*

Residential cables would be PVC/PVC. probably 1.0 mm or 1.5 mm for lighting. two core and earth. Sockets would be 2.5mm two core and earth

Current loads are 12 amps/16 amps and 32 amps respectively.











Where a third core is required ie trwo way switching or further live feed - 













External cable to a garage for example would be via Single Wire Armoured cable of the type shown. Glanded at both ends.


----------



## frank (Feb 6, 2007)

*sockets and switches*

Typical UK wall switch. The switch is down for on in residential locations. Up for on in Industrial locatations ??????????














Typical dual 13 amp socket.












Each plug head has a local fuse. You can change this fuse between 1 amp and 13 amps. Saves inconvenience of blowing all the circuit on fault mode.












Final plug head picture. 3 pin fused head.











Now it's time to plug in and make the tea.

Frank


----------



## brian john (Mar 11, 2007)

Frank:

Lighting is separate from outlets?

Outlets are on a loop? I assume Over Current Protection on each end? W call this a back fed circuit and is usually a mistake.

Rosebuds? Very close to what we call an 8B 3-1/2" round.

Do all residential roesbuds and outlet boxes have terminals?

Your 12 amp appears to be our #14 AWG (American Wire Gauge) which is rated 15 amps and 12 amps for continuous loads (continuous loads on 3 hours are more, additionally other loads fall into this 80% load category).

16 amp appears to be our #12 AWG which is rated 20 amps and 16 amps continuous loads.

Your 32 amp would be our #10 AWG rated 30 amps and 24 amps continuous.


----------



## MDShunk (Jan 7, 2007)

I'm very curious to know how and where each end of the "ring" connects at the consumer unit. I'm also curious to know what the advantage is to feeding both ends of the ring, if that's what's happening.


----------



## frank (Feb 6, 2007)

*loop sockets*

Having a great day today. Anne the wife is at work (daughter in laws bridal shop) free of course! The sun is shining in a clear blue sky. Air temp is 22C ( for you folks that 73F) and I am playing between - spraying cabinets on my old radios - keeping tabs on the comptuter - brewing tea and dipping cookies. The perfect life!

So Marc. Loop socket circuits. The ends of each live go to the same mcb output and the neutrals of course to the same busbar. Utilising a loop provides increased current demand and convenience for a cable sized the same as a radial. Current along two //ll paths etc. But combining at the single point of overload demand keeps installation costs down in terms of cable, mcb's and distribution board size. A safety feature built into the design is the maximum Kva you can get from one outlet. Since the plug heads feeding appliances are localy fused that's 2.9 kVa. Well below the handling characteristic of the cable. The circuit mcb is 32amp. There are regs ccovering the number of outlets over a given area but in domestic work you can mostly assume as many as you wish since volt drop will not amount to much. The only other consideration would be temperature problems if the cable was in some form of insulated void or such. Otherwise.......wire away.


Ceiling roses have brass terminals within them . Usually 4 number. Live.Neutral, Earth. Loop.













Frank


----------



## MDShunk (Jan 7, 2007)

Okay, so both ends of a loop circuit start and end at the same circuit breaker. Neat. You'd never really know if you had a bad/loose connection someplace on the circuit, then, would you? It would just be back-fed from the other side of the loop. I suspect this arrangement (high capacity loop circuits, with fused plugs) is one of the things that keeps your total number of circuits low when compared with a North American style system. Some of your consumer units for an entire dwelling, to me, seem barely large enough for the typical North American garage or hobbyist's workshop. Perhaps the only rough equivalent to this system in North America would be busways in industrial establishments. A large, high current buss runs down through a section of the building, normally near the roof. "Buss plugs", containing fuses or circuit breakers can plug on at frequent intervals to provide power to distribution panels or machinery. Perhaps you have the same arrangement in the UK in industrial establishments?


----------



## frank (Feb 6, 2007)

Marc.
The downside to this system is the open circuit aspect as you noted. Does it happen. yes it does. But it is calculated in ' whats the chance' category. If you should find yourself with two //ll radials instead of a loop, the rated 'radial current capacity' of the cable is within the capacity of the mcb anyway. Most* average *homes have 3 loop circuits. One to the kitchen and one to each floor.

The arrangement for industry is just the same as yours.


Frank


----------



## John (Jan 22, 2007)

Frank,
You are talking about 240 Volt loops aren't you. I assume that most of your appliances are 240 VAC.


----------



## frank (Feb 6, 2007)

John.

Yes. But to be correct it is now 230V. The voltage range was changed about 3 years ogo.

So we are 230 Volts 50 Hz Single Phase and 415 Volt 50 Hz 3 Phase.



Frank


----------



## brian john (Mar 11, 2007)

OK so I am a NUT, but when I travel as the family is checking out the sites I look at the electrical systems.

I think in the UK (correct me if I am wrong) a residential distribution transformer is a single phase 230 to neutral/grounded conductor. You're distribution panels have one phase/hot/energized bus and a neutral bus?


----------



## frank (Feb 6, 2007)

Brian. If you are a nut then I must be also. When on holiday I have a neck like an ostrich. Who wants to take in the Seven Wonders of the World when there are conduit and trunking systems to drool over. I have flown into Logan Airport Boston. twice yearly since 1987 and I know more of what hides behind the ceiling panels due to the airport upgrade than the airport manager.

To your point about UK residential supply's, yes the supply transformer for domestic dwellings is 230 volts and a supply current of 100 amps. The neutral is bonded to earth at a point below the supply meter by the supply company. An electrician would leave the three cores - L-N-E hanging loose below the Consumer Unit for the Company to connect to the Mains.

Dwellings needing more than 100 amps would apply for 3 phase but it would be unusual unless you lived in a mansion. Like yourself perhaps! WE call this bonded earth'nuetral ' protective multiple earthing'. where such a system is installed an 'equipotential cage' has to be established within the dwelling to the effect of bonding all metal work that could carry at some point a fault current. So direct bonding to the consumer unit could include Water pipes.gas pipes,oil pipes. Cross bonding would include radiators,sinks,baths,girderwork.boilers.showers and so on. I have even seen bathroom grab rails bonded. But that;s just plain daft.


Frank


----------



## MDShunk (Jan 7, 2007)

In the receptacle picture, what are the two things in the middle that look like switches? Switches for lights? A disconnect switch for each receptacle? Something different?


----------



## JohnJ0906 (Jan 22, 2007)

Marc, I think they are disconnect switches for each receptacle, but I could be wrong


----------



## MDShunk (Jan 7, 2007)

JohnJ0906 said:


> Marc, I think they are disconnect switches for each receptacle, but I could be wrong


That's what I was thinking, too. I'm not sure how that would be useful. I see also, what looks like shutters inside the hot and neutral holes. I wonder if they're tamper resistant? The hot and neutral holes look like they're off-white colored inside and the ground hole looks black. That's what makes me wonder.


----------



## brian john (Mar 11, 2007)

They are switches, My in-laws shut off all the switches and unplug all equipment before they go out. I am sure this is just them...

With the switches of plugging in anything (like a laptop) avoids any inrush current arcing.


----------



## frank (Feb 6, 2007)

Hi folks.

The switches isolate each outlet. They are sometimes mounted as you see them in the middle or otherwise to each upper side of the outlet. The outlets are just as you noticed Marc. Shuttered. The earth pin of the plug head is longer than the other two. When this enters first it opens the shutters for the pins of live and neutral to enter. Keeps young sticky fingers from poking odds and bobs inside. And as a note to this - all circuits must be dedicated ie; lights for lights. sockets for sockets.Etc.

Frank.


----------



## brian john (Mar 11, 2007)

When I did my house I had a circuit for each bedroom each bathroom, with seperate lighting. Same family room and living room, den. Does make it nicer when one trips a circuit, All outlets are GFCI and am going to change to AFCI.


----------



## frank (Feb 6, 2007)

*More of same but different.*

These snaps show more of the residential accessories you would come accross in the UK.


Picture 1. This is a switch fused outlet. Used for a hard wired item. ie heater,fan,air, fridge washing machine etc .Anything you would not normaly move.












Picture 2. This is a neon indicator. Just a notification really that you have some item or other switched on but the isolator is in a remote location.














Picture 3. This neon indicating switch is for a dedicated circuit. Double Pole 50 amps. used as an isolator for cooker units etc. You can buy them either as a horizontal unit as shown or a a vertical unit if you prefer.













Frank


----------

