Observations From France

[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....