Observations From France

[Mr.Simple]

Guys, I will again point out that I am not an electrician but an electronics engineer, so please be patient with me. I recently chatted to a French electrician to identify some key and basic differences between here and France. I was surprised at some of them and thought that most had merit, and decided to share for feedback. Please approach this with an open mind rather than an automatic British is best.

1. They have no ring circuits, all are radial. Power is delivered via 2.5mm wires to up to 8 sockets protected by a 20A breaker. This means that a fault in the wiring results in the customer seeing no power in part do the cct, and they then call someone in to fix it. Here if a ring breaks down all of the CCT remains live and the customer is unaware of the fault.

2. High load appliances, dishwashers, washing machines, tumble driers etc, have dedicated circuits protected by appropriate breakers. This extends the concept that we use for cooker circuits.

3. The breakers in the Consumer unit are double pole switching both live and neutral. This means that if for any reason the polarity is wrong throwing the consumer unit breaker will always isolate the circuit. I know that people may argue that polarity is treated, but are there ever mistakes?

4. The bus bars (live and neutral) lie above the breakers, with the circuit wires coming from the bottom of the breakers. I think in the uk our live bus bar is at the bottom with the circuit lives coming from the top of the breakers. This seems plain wrong as we all know that electricity flows better downhill (electrons are affected by gravity too).

i welcome your thoughts

 

[telectrix]

your points 1,2, & 3 all have thier merits, but as fot electrickery flowing better downhill, it's time for your tin hat. these used to be popular in france:

 

[Pete999]

So that's why they say it;s best to install the consumers unit at a higher level, to get a better flow, marvelous

 

[Marvo]

You can overdo it though, if the CU is mounted too high the electrons can get scared resulting in unstable voltages.

 

[Mr.Simple]

You can overdo it though, if the CU is mounted too high the electrons can get scared resulting in unstable voltages.

That will explain why CU's are usually mounted in cupboards. As a CU in a tower block would be very high It would be necessary to ensure that they don't see how high they actually are.

 

[telectrix]

:76:heree we have some tower block electrons.

 

[Marvo]

That will explain why CU's are usually mounted in cupboards. As a CU in a tower block would be very high It would be necessary to ensure that they don't see how high they actually are.

It's also the reason most wires are insulated, an ignorant electron is a happy electron

 

[telectrix]

ah, but what about those electrons that have only done a Electrical Trainee course. should they be confined to ELV?

 

[Engineer54]

Guys, I will again point out that I am not an electrician but an electronics engineer, so please be patient with me. I recently chatted to a French electrician to identify some key and basic differences between here and France. I was surprised at some of them and thought that most had merit, and decided to share for feedback. Please approach this with an open mind rather than an automatic British is best.

1. They have no ring circuits, all are radial. Power is delivered via 2.5mm wires to up to 8 sockets protected by a 20A breaker. This means that a fault in the wiring results in the customer seeing no power in part do the cct, and they then call someone in to fix it. Here if a ring breaks down all of the CCT remains live and the customer is unaware of the fault.

2. High load appliances, dishwashers, washing machines, tumble driers etc, have dedicated circuits protected by appropriate breakers. This extends the concept that we use for cooker circuits.

3. The breakers in the Consumer unit are double pole switching both live and neutral. This means that if for any reason the polarity is wrong throwing the consumer unit breaker will always isolate the circuit. I know that people may argue that polarity is treated, but are there ever mistakes?

4. The bus bars (live and neutral) lie above the breakers, with the circuit wires coming from the bottom of the breakers. I think in the uk our live bus bar is at the bottom with the circuit lives coming from the top of the breakers. This seems plain wrong as we all know that electricity flows better downhill (electrons are affected by gravity too).

i welcome your thoughts

One very big drawback for applying all those items 1. 2. 3, which is the size of the CU that'll be required to contain all those extra MCB's. Then virtually double it for them being DP breakers!!!

 

[ArseyDee]

One very big drawback for applying all those items 1. 2. 3, which is the size of the CU that'll be required to contain all those extra MCB's. Then virtually double it for them being DP breakers!!!

But on the plus side, it would require a nice big dedicated space, rather than awkward access to our existing CU's buried at the back of the shoe cupboard or in a kitchen base unit, etc, etc......

 

[Lighthouse Phil]

Apart from the DP breakers, the wiring here in Ireland is very similar. We'd have two 20A radial circuits for kitchens (or more, depending on size of room),

We also have neutralised electrons, they don't know the difference between up or down, left or right.. Don't ask how the electrons get neutralised, its a long story......

 

[bigspark17]

Intresting post mr simple..
Point 1- big draw back of radials is loading isusses and u say if there is a problem the circuit stops working well this isnt true if the cpc is lost on one of the first sockets leaves the rest with no cpc connected could be very dangerous with some class 1 equip.
Point 2- love it if it suits.. Often wired dishwashers, tumble dryers microwaves on their own supply!
Point 3- yeah great idea to have double pole breakers commercially but domestically isnt going to happen i belive the rcd covers this adequatly enough.. Dont wanna do ourselfs out of any callouts!
Point 4- load of rubbish really!

 

[Mr.Simple]

One very big drawback for applying all those items 1. 2. 3, which is the size of the CU that'll be required to contain all those extra MCB's. Then virtually double it for them being DP breakers!!!

you are quite right that there are likely to be more McB's than a typical uk installation, but is that a bad thing? However you are wrong about the size of DP MCB's they are exactly the same size as a uk variety, now twice the size. The French also seem to like to have CU's that have multiple rows of MCB' and these are not much larger that a typical Uk variety ( less wide but a bit taller).

 

[Deleted member 72666]

All I can say on the matter is at least our plugs are fused! :rockon2:

 

[telectrix]

yeah. usually into the socket if the load is > 8A.

 

[Engineer54]

you are quite right that there are likely to be more McB's than a typical uk installation, but is that a bad thing? However you are wrong about the size of DP MCB's they are exactly the same size as a uk variety, now twice the size. The French also seem to like to have CU's that have multiple rows of MCB' and these are not much larger that a typical Uk variety ( less wide but a bit taller).

We must be looking at different sized DB's then because the examples i've seen in France are decidedly bigger than a typical UK CU. Depending on the installations size, it's not uncommon to see 3 RCD units of 2 different types and an outlet in French DB's. God forbid if that DB also has pulse relays for the control of lighting circuits (can't remember the correct name for them).

Yes you could be right on DP MCB's, we make use of those single pole with switched neutral MCB's and RCBO's in some of our Lab installations....

 

[Marvo]

...we make use of those single pole with switched neutral MCB's and RCBO's in some of our Lab installations....

We also use them in certain applications. They're known as SP&N (single pole and neutral) breakers locally.

 

[Knobhead]

To me the use of SP+N MCB’s makes sense. But then I was brought up with centre tapped 230V under M&Q where every thing had to be DP.

I never did do much domestic stuff, it works out at one house every eight years.

I don’t like radials, they smack of being a simplistic easy get out.

 

[Lucien Nunes]

pulse relays for the control of lighting circuits (can't remember the correct name for them).

Télérupteurs?

Points 1&2 are not so much observations from France but from the rest of the world. We are the odd one out, with a canny system that relies on diversity to save material. It usually works quite well but is technically a fudge, often done wrongly and painful to test. It goes hand in hand with fused plugs which are equally a mixed blessing.

Point 3 I would like to see here too. Since the ESQCR and the revisions to the 11th edition did away with DP fusing (because the neutral was then deemed to be in permanent and effective contact with earth) a tradition has grown up of fiddling about with screw terminals to isolate a circuit. It didn't matter so much when nobody did EICRs and there were no RCDs - you could put your cutters through a cable and if the fuse was out it didn't go bang. But now that's not possible, you have to take the wire out, which is daft. Likewise, in the event of a fault causing a trip, it's handy if the circuit is then completely isolated from the rest of the system so as not to cause further trouble until repaired.

Point 4 - It's easier to install and check cables in the top of breakers unless the board is above your head. DB technicalities seem to be over the heads of many so-called electricians these days.

 

[Engineer54]

Points 1&2 are not so much observations from France but from the rest of the world. We are the odd one out, with a canny system that relies on diversity to save material. It usually works quite well but is technically a fudge, often done wrongly and painful to test. It goes hand in hand with fused plugs which are equally a mixed blessing.

Eh, ....diversity is a fundamental necessity, that is used on all distribution networks and installations throughout the world, so i'm not sure what you mean by the UK being the odd one out?? Without applying diversity, you would have cable sizes that would in most cases, be impossible to connect to standard sized electrical equipment . One things for sure it's far cry from being a technical fudge.

I'll agree with you, that to get consistently accurate max demands you need to have a good deal of experience under your belt and be well versed in how you go about it....

 

[gnuuser]

in some cases we use both radial and ring circuits but they must be labeled correctly
same as the circuits in the cu
for example on a lighting ckt the label attached to the conductor would have the maximum breaker size info printed on it.
balancing loads in a radial is an impossibility for the average consumer as they rarely get training on it, and find out they have too much on it when the breaker trips out.
recently i was given a laptop comp with a uk plug on the power pack.
it was an auto switching power supply so it was just a cord swap to use it.
by the way i really like the way the uk plug is designed (fused and rock solid construction)

my biggest complaint with diy and some hack sparks is they will just tap the nearest live conductor without checking its loads and install a utility outlet for heavy loads.
or install a breaker that exceeds the ampacity of the conductors.

 

[overskilled]

From living in North America, I found the NEMA plugs ok for size, but the blades far too flimsy (stand on one...it bends...stand on a uk plug pin...you come off worse)
Also know what you mean about overloaded radials, father in law has a compressor in the basement, turn anything else on while the compressor is running...breaker trips out...
Other thing about NEMA plugs that isn't the greatest is the ability to remove the earth/grounding pin with little or no difficulty....(usually to use them with 2 pin extension cords or ancient outlets...)
Stove plugs aren't a bad idea though...some serious connector pins on those. If I remember correctly theres different 220v plugs depending on the amperage i.e. dryer plugs (20 or 30amps), stove plugs etc...
Though why single insulated "flat" extension cords are still permitted escapes me.....

 

[overskilled]

Also....I never quite got my head round the choice of black and white for conductor colours....though the different pin colours inside rewireable NEMA plugs isn't a bad idea nickel / brass

 

[Lucien Nunes]

so i'm not sure what you mean by the UK being the odd one out?

I meant general use of ring finals. Higher circuit rating, more outlets per circuit, more diversity. You get more flexibility from 1x 32A than 2x 16A but at the cost of complexity and being able to overload the cable. It's a different kettle of fish to ring MV distribution.

 

[Victor]

It is not unusual for me to install a 54 way CU in a 3 to 4 bed house, infact the last one I did a few weeks agr was a 72 way with 4 RCD's

 

[Silly Sausage]

It is not unusual for me to install a 54 way CU in a 3 to 4 bed house, infact the last one I did a few weeks agr was a 72 way with 4 RCD's

!!!!!!!!!!!!

Pays well being an Electrician in France???

 

[Victor]

!!!!!!!!!!!!

Pays well being an Electrician in France???

Not when your materials for a 4 bedroom 2 bathroom house are in the reigion of Euros 3.5k and you pay the tax man 40% of turnover it ain't

 

[telectrix]

haha, well the french government are still paying for the maginot line. money's got to come from somewhere. LOL.

 

[RogertheBodger]

haha, well the french government are still paying for the maginot line. money's got to come from somewhere. LOL.

There's usually a way round it lol

 

[Engineer54]

I meant general use of ring finals. Higher circuit rating, more outlets per circuit, more diversity. You get more flexibility from 1x 32A than 2x 16A but at the cost of complexity and being able to overload the cable. It's a different kettle of fish to ring MV distribution.

Ah, i understand what you were referring to now, not that i would wholly agree with you on the matter though!! ...lol!!

MV ring's are rarely working in a ring configuration, they mainly operate as open rings. The main idea to MV rings is that you can totally isolate, say any RMU or interconnecting cable between RMU's while still supplying all the other RMU's on the ring. Or supply the whole installation from either of the two supply sources....

 

[Marvo]

It is not unusual for me to install a 54 way CU in a 3 to 4 bed house, infact the last one I did a few weeks agr was a 72 way with 4 RCD's

You are joking I assume. I also live in a land where 20A 2.5mm radial circuits are the domestic norm. A normal 3 bedroom house with all the usual appliances would require 3, or maximum 4 radial ccts for sockets, also a dedicated radial for immersion heater and maybe another dedicated radial for swimming pool and/or garage. If you include 2 lighting radials (one upstairs and one downstairs) you're looking at a 12-way DB including main and RCD, 16-way will have plenty of future proofing. If you install a 54 way box you'd have at least 40 ways spare.........a 72 way would have 60 ways spare, handy if you need more cupboard space or somewhere to conceal your gun safe maybe

 

[overskilled]

I could see 32 possibly if its DP MCBs.... (2 ways each)
72 though....how big a house are we talking? :/

 

[Marvo]

D/P MCB's sometimes only take the same space as a single pole

 

[overskilled]

I realise that Marvo
I was just looking at a worst case scenario...

 

[Engineer54]

You are joking I assume. I also live in a land where 20A 2.5mm radial circuits are the domestic norm. A normal 3 bedroom house with all the usual appliances would require 3, or maximum 4 radial ccts for sockets, also a dedicated radial for immersion heater and maybe another dedicated radial for swimming pool and/or garage. If you include 2 lighting radials (one upstairs and one downstairs) you're looking at a 12-way DB including main and RCD, 16-way will have plenty of future proofing. If you install a 54 way box you'd have at least 40 ways spare.........a 72 way would have 60 ways spare, handy if you need more cupboard space or somewhere to conceal your gun safe maybe

If you look in the non-UK Forum, the French spark (forget his name now) posted a photo of a typical domestic French DB, and from what i remember it was very much along the lines of what Victor is saying. Also the French make use of pulse relays quite a lot on lighting circuits, which also adds to the space required in any DB, ...not forgetting the i think obligatory DB Din rail mounted socket outlet!!

I can remember a hospital project in Saudi many moons ago that included staff villas and the like, where the electrical spec was based on French installation standards. Believe me, i'd never seen domestic DB's of the size used on that project. MCB's RCD's and those pulse relays galore!! lol!!

 

[Victor]

The main problem here is that the required number of RCD#s depends on the size of the property, so for a house over 100sqm the required number is 4 of which one would be a type A and the rest type AC. When you combine that with only 8 sockets per circuit and 8 lights per circuit then you really start to fill up a CU.

Regulations also state here that for a new installation or a renovation you must leave 20% of the cu free for future expansion and that you must install 2 x sockets in the cu, it does not take a lot to fill up a 54 way board and if you have electric heating the a 72 way is easy to fill.

 

[Knobhead]

Always thought the French were crazy. Now I know.

OK DP or SP&N switching makes sense. We should adopt it. I do like latched relays for lighting.

No way would a house warrant a 72 way board.