Some wiring questions

[Butchx5]

Hi - asking on behalf of  my hubby so excuse my wording - and I hope I got the questions right!!

Hoping a few of you 'in the know' can help with a few electrical wiring question:

1.   We have had our home electrical supply changed from tri-phase to mono-phase - no probs - but what do we do with the two 'tails' now left unconnected?

2.   Can you buy the special connectors to join the earth cable to all metal pipes, etc in the bathroom (as you would use in UK) can't find anything to use at all and the stores just shrug and suggest just wrapping the cable round the pipe - that can't be right?

3.  Where within the system are you required to fit the barette de terre - I assume somewhere along the earth cable joining the Tableau to the prise de terre - but where? And is a barette de terre the same thing I see sold as a coupe circuit with two insulators attached?

Can find no reference to these questions anywhere - not even in our existing home wiring!!.

Thanks in advance

Helen

 

 

[derf]

 

Have a look at the link below.

http://www.completefrance.com/cs/forums/608930/ShowPost.aspx

[powerdesal]

Helen,

The barette de terre is literally the earth bar, this is usually in the

tableau d'electricite or the consumer unit box to some of us. Its where

all the individual circuit earths meet up and it is then connected to

your main system earth at the earthing pin in the ground outside (cant

remember the French term for that). In between the earth pin and the

house earth cable is the coupe circuit which is a disconnectable link

to allow earth resistance tests to be done to check the 'efficiency' of

the ground earthing. This test is NOT something you can do with your

ordinary multi-meter.

The earthing clamps to pipes I cannot help with, perhaps you could try other brico-sheds or import from UK.

The redundant ex-3 phase tails are hopefully dead and could possibly be taped up and tucked away!!!!!

Check they are dead before any touching or get a professional spark to

do it if you do not have the necessary expertise. Live wires do not

give you two chances!!!!!!!!

Regards

[La Guerriere]

It's more efficient and makes better use of your abonnement to try and balance the three phases and run part form each phase i.e. have a tableau with three rows, each running one of the three phases.

I haven't seen the special "cross-bonding" earth straps as used in the UK. Could use either the UK type straps, jublilee clips or simply solder the wire to the outside of the pipe (only practical if drained) 

The idea of the barette de terre is to be able to disconnect the house earth system from the prise so the prise de terre can be tested, so, yes, it goes between the tableau and the prise de terre as convenient

[powerdesal]

prise de terre, ----that was the name I couldn't remember !!! Thanks La Guerrier.

[powerdesal]

Correction to my earlier post,

The earth link between the house earth lead (from the barrette de

terre) to the prise de terre is called the barette de coupure or

barrette de mesure in some references. The main earth lead is the

'conducteur principal de protection'

I recommend  ' L'installation electrique' by Thierry Gazauziaux

& David Fedullo, ISBN : 2-212-11431-1 and see page 199 et al.

Regards

[Anton Redman]

Never seem to see the straps in the DIY sheds but proper electrical wholesalers stock them. Alternative is braise/solder earth wire between copper pipes as above.

[fulcrum]

I would like to ask someone who knows for sure. Where does the Barrette de Mesure actually go. I know it fits in series with the "Conducteur Principal de Protection" (10mm or 16mm earth wire from distribution box) and the "Prise de Terre" (earth spike or buried copper earth). But where exactly. Should it be accessable at the Prise de Terre end or the Distribution box end.

I have a book based on the Normes NF C15-100 but it doesn't show it exactly. I even have it shown as a "Barrette de Coupure"

Thanks

[powerdesal]

My interpretation is that the test point should be immediatly above

ground outside the property for access by EDF / Consuel for insulation

resistance measurement. I am quite prepared to be corrected.

[Anton Redman]

All the French houses we looked at had a way of disconnecting the earth below the switch board but inside the house presumably to test the earth connection's effectiveness.

[fulcrum]

Powerdesal and Anton

Thanks for your replies.

[friend of stouby]

"It's more efficient and makes better use of your abonnement to try and balance the three phases and run part form each phase i.e. have a tableau with three rows, each running one of the three phases."

Sorry to act dim La Guerriere, but why does it make better use of your abonnnement by balancinng the 3 phases?

We move in next week and have to meet with the EDF sometime soon after, our fermette has 3 phase now so you suggest it may be better to keep it?

Ta

Jamie

 

[La Guerriere]

The EDF abonnement gives you a certain power allowance typically say 45A. With a mono system you can puill all 45 A from the system. With three phase this is split over the three phases 3 x 15A. If you only use one phase you only have 15A available so you need to split the load over all three phases.

So phase 1 might have some lighting, some power say the cooker, phase 2 have some lights some power like ground floor points and the chauffe eau, phase 3 the rest of the lights, other points and some heaters. The main problem is to avoid any possibility of confusion and getting cross-phase wiring. Each phase must be kept very separate with careful colour coding. All electricity is dangerous and three phase is particularly dangerous. A mono shock is potentially lethal, a tri shock across phases is almost certainly lethal.

[Iceni]

[quote user="powerdesal"]My interpretation is that the test point should be immediatly above ground outside the property for access by EDF / Consuel for insulation resistance measurement. I am quite prepared to be corrected.
[/quote]

When CONSUEL carried out his inspection he measured earth resistance on the bar inside the box but then went outside to visually check the earth spike. Though for all he knows it might be only an inch or two in the soil.

John

not

[friend of stouby]

Hello Jim

I have the point about using your full three phase allowance by splitting the draw on the phases as equally as possible, but is there any advantage of having the same power coming into a property via a single or three cables? Or to have a three phase supply in a regular domestic property. There must have been a reason that the EDF fitted up 3 phase to start with I suppose? 

A while ago a friend was told to keep his three phase set up against going to mono, I didn't understand that then but didn't have the chance to ask why.

Thanks for taking the trouble.

Jamie

...butchx5   sorry, I didn't intend to hijack your thread

[Alcazar]

My earth spike, a full four feet of it, replaces a useless one I found in the cellar, and is driven to it's entire depth, barring about 4", into an earth floor. It's a Screwfix copper rod with a clamp on the top for the earth cable, and the end of my earth cable is soldered into a ring-tag, and bolted to it.

The barette de mesure is on the kitchen wall, just above floor level, where the main earth wire comes down to the cellar.

My plumber, who is also an electrician, gave both the thumbs up, although he did say he would have used 16 mm sq cable for earth, not the 10 mm sq that I used.........now changed.

Alcazar

BTW: if anyone wants some earth connectors for bonding pipework to earth, (equi-potential bonding), let me know. I'm coming over around the middle of April, and will galdly bring a few, and post them to you in a jiffy-bag.

[Anton Redman]

" There must have been a reason that the EDF fitted up 3 phase to start with I suppose?  "

You can transmit the same amount of power with lower transmission losses and can you a smaller total amount of wire to transmit the same power. Remember just how spare the population / demand is in some areas of France.

I am sure that word was sparse when I typoed it.

[Butchx5]

Hello again

Thanks to all those who helped out with our questions - here is an update:

Managed to get some equipotential bonding fittings from Castorama - were quite big and were €1:45 each so anyone planning a rewire would do well to source them from the UK.

Sorted out the barette de measure/couper problem too - thanks. Mr Bricolage actually has a leaflet with quite good piccies and explanations on the whole Earthing subject. (Possibly also available online - haven't looked yet)

BUT we still have a bit of a query about the three 'tails' which were our tri-phase which in theory now should only be one as we are mono- phase - We tested them and ALL 3 are in fact live. Any bright spark able to offer some suggestions about how to deal with them now we know this? My idea is to bring all three into a 'block'  (which I shall hide in a mini coffret) and then bring one tail out to my tableau - does this seem acceptable/safe?

Now have a new question regarding the Interrupteur Differentials and the A or AC type - and which type to use for each type of appliance?

It is very frustrating as we have found that we get conflicting information regarding a lot of points regarding French electrics depending upon which book or source of information we check (all new and all French I hasten to add) and they all state they conform to the up to date requirements - is the subject really that varied and still able to comply? Do you all have this problem?

Thanks again in anticipation of your helpful replies.

Mike

 

 

[fulcrum]

Butchex5

I would get a proper French registered electrician who can sign off the work on securing the spare tails. Actually I would imagine whoever converted your supply to single phase should be made to complete the job.

Whatever some might tell you. Three phase is not just three lots of 220volts. Sometimes the phases can be 415volts across and so electrocution is a deffinate possibility.

[Alcazar]

IIRC, the type AC RCD is for most things, the type A is for washer, dishwasher, tumble drier, and large electric, (induction? halogen?), hob, although NOT the oven.

I THINK it has something to do with whether the device has a large elctric motor, so can generate accidental DC voltages, but don't quote me on that.

I'd recommend buying "L'electricite pas a pas", available in paperback from Lerclerc, among others, and a mine of info and easy to follow diagrams, all for around €5.

Alcazar

[La Guerriere]

On three phase, each phase, let's call them P1 , P2 and P3 should have 220 v between each phase and neutral. But, by definition the three phases are AC and are 120 degrees out of phase with each other, so the voltage across phases, say P1 and P2 varies but has a maximum of 415 volts, which will definitely knock the varnish off your portrait.

 I still don't think it wise to just use one phase and blank the others off, it's a waste of good abonnement. If in doubt, find an electrician.

[napoleon]

[quote user="Butchx5"]

BUT we still have a bit of a query about the three 'tails' which were our tri-phase which in theory now should only be one as we are mono- phase - We tested them and ALL 3 are in fact live. Any bright spark able to offer some suggestions about how to deal with them now we know this? My idea is to bring all three into a 'block'  (which I shall hide in a mini coffret) and then bring one tail out to my tableau - does this seem acceptable/safe?

[/quote]

Mike,

 The supply in our house had all three phases brought into the EDF switch unit but only one was connected to the meter via internal "jumpers". It is normal for all three phases to be live even if a consumer uses just one. EDF expect to find three tails to connect to their unit and give you a single phase ouput to the meter (The other two simply stop on the input side and are not connected in any way to the output). A three phase wired house requires a special three phase meter. They will not provide three phases after the meter if you have opted for single phase.

                                                           Regards, Alistair

[powerdesal]

Butchx5 / Helen,

Could I ask a basic question, why exactly did you ask for a change from 3 phase to single phase in the first place ?

Regards