FUSE SIZE FOR RING MAIN

[Yvonne]

Help!

Can anyone tell me what size of fuse we should expect in our ring main in France? we currently only have a 10A fuse which seems to blow when we use more than 3 / 4 sockets at a time! I know that in the UK it could be 30A for ring main but is it different here in France?

Thanks!

 

 

[Michael]

[quote]Help! Can anyone tell me what size of fuse we should expect in our ring main in France? we currently only have a 10A fuse which seems to blow when we use more than 3 / 4 sockets at a time! I know th...[/quote]

Ring mains are not used in france full stop.

[Piprob]

abim, how do you know it's a ring main? We can see you didn't instal it, but who did? If it was installed by a French Electrician then each outlet will come direct from the main board. If your property was owned/ renovated by someone from the UK, then it is important that you check what kind of installation they have left you. There are better qualified people than me who post on this subject.

[Ianhaycox]

Firstly don't just put in a larger fuse. The fuse is there to protect the wires overloading/overheating in the walls and potentially starting a fire.

Have you got lots and lots (maybe 10 or more) of fuses in a 'fuse box' similar to the UK ?

Are the fuses breakers (i.e push to reset) or small ceramic cartridges you need to replace ?

Do the sockets have two pins ? I.e. is there an earth ? Are they French sockets, not UK ones ?

10A is not enough if you plug in a kettle and a toaster and a coffee maker on the same circuit. It's quite likely to blow.

Any more info that might help us diagnose your problem.

[JohnM]

I'm going to assume that you've used the term "ring main" because that is the phrase that you will have heard banded about in the UK, but I'm also going to assume that you have spurs which is how the French do it. If you really do have a ring main then take further advice. For spurs 10amp is about right. With a ring main, the electricty can go both ways to get to a socket, so the power rating of the cable is doubled. However with a spur it isn't. With spurs you should be comparing the 10amp fuse with the 13amp one that you would have in your UK plug. Not much difference.

If you do have a spur I hope that you have more than one, so do a check. Take a fuse out, plug a table lamp into all the sockets and see which ones it works in. Then do it for a different fuse. You should find out that (for example) sockets 1, 4 and 6 are on one spur, 2, 5 and 7 are on another etc. Make a note of this and ensure that you don't plug two heaters into the same spur.

Does that make sense / help?

 

[Yvonne]

Thanks to everyone for the informative responses.

Here goes...yes, it is a french system and no we didn't install it. The 'spur' in question forms a 2 bedroom apartment within a 10 bedroom hotel so, yes, there are many different fuses and also many 'trip' switches. When the sockets blow in the apartment - they all seem to be connected to the same fuse (same spur?) except for just one socket which continues to work. If the fuse is only 10A then does this indicate that we should not have all of these sockets onto one spur:

1 x bathroom socket (occasional hairdryer / heater)

2 x lounge sockets - TV, stereo etc

4 x bedroom sockets (lamps, 2 x occasional heaters)

4 x kitchen sockets (small fridge, kettle etc) plus heater.

NB: the kitchen electrics are all spurred from one of the bedroom sockets and were installed whilst we've been here (not by us whcih is why we undersatnd very little!).

Many Thanks for any further advise that anyone can offer. At the moment we change the fuse daily!!

 

 

[DMC]

Power to the kitchen sockets would normally be fed straight from the fuse box on a separate 'spur'. Also, your kitchen heater should be fed on a separate spur straight from the fuse box. If your description is accurate and your kitchen is fed from a socket as a recent addition - it sounds like an 'iffy' installation.

Doug

[Yvonne]

hmmmm!!

Many Thanks!

 

[Alcazar]

My book, backed up by my local plumber/electrician tells me no more than 6 sockets per spur.

Your kitchen installation sounds downright dangerous

Alcazar

[Ianhaycox]

I wouldn't regard your installation as dangerous, as long as the cable section is 1.5 mm2 or more on the spur (which is highly likely).

The fuse blowing is a pain, but it's just doing it's job, protecting the installation.

As mentioned before, your choices are really,

1. New spur(s), or,

2. plug less things in !

Adding a new spur is not very difficult especially if you are happy to have the wires run within conduit (trunking) 'exposed' on the wall.

BTW my book says it's OK for 5 sockets on 1.5mm cable and 8 on 2.5mm cable.

Thickness is most important.

[Charlie Nott<P>Many Thanks<P><P>Charlie Nott<P><P><a target=_blank href="http:www.giteshols.com">www.giteshols.com<A><P>]

This is scary. I am an electrical engineer and to hear recommendations that 1.5mm cable should be used for sockets (Prise de courant) is highly dangerous.

Under the Promotelec regime (the best) then a maximum of 5 sockets are allowed (a double socket counts as one), the section is 2.5mm, it must be earthed with 2.5 mm cable and the breaker should be 25A MCB (disjoncteur) or 20A fuse (fusible).

Also you must now split the circuits for Washing machines, Dishwashers, cookers, immersion heaters (i.e. anything that could get wet) onto a totally separate fuseboard and use a type A RCD (differentiel) on this circuit and a type AC RCD (differentiel) on your other circuits.

[Punch]

[quote]This is scary. I am an electrical engineer and to hear recommendations that 1.5mm cable should be used for sockets (Prise de courant) is highly dangerous. Under the Promotelec regime (the best) then ...[/quote]

With due respect and please don't take offence or get me wrong Charlie that's totally incorrect, and not at all dangerous.

The French wiring regulations allow socket outlet circuits to be wired in 1.5mm cable. The maximum number on this type of circuit is 5 sockets (a double counts as 1), and the circuit must be protected by either a 16 amp disjoncteur (mcb) or a 10 amp fuse.

The regulations also allow up to 8 sockets wired in 2.5mm cable, protected by 20 amp disj (NOT 25amp), or 16 amp fuse. You are correct in saying that if you want the "Promotelec" label, which is usually on new build then they recommend only five sockets. Personally, as a working electrican here in France, I nearly always put 8 on a circuit as it is often the case that just one bedroom could use up the 5 allowance, making wiring seperate radials to each room impractical espescially when they are only being used for table lamps etc. Points for heaters are wired seperately too in France.

There is no need for a seperate fuseboard for the appliances you mention, but the circuits you mention should be wired as seperate radials. RCD protection should be installed for all power type circuits ie: socket outlets and appliances, and ALL circuits in a bathroom.

best regards,

Paul

 

 

 

[Charlie Nott<P>Many Thanks<P><P>Charlie Nott<P><P><a target=_blank href="http:www.giteshols.com">www.giteshols.com<A><P>]

Dear Paul

With greatest respect I beg to differ. Under the latest release of NFC 15-100 it is recommended to install 2 circuits. One (Rangée inférieure) using a type A RCD and one (Rangée supérieure) using a type AC RCD. I have checked this recently with my Legrand rep and he concurs.

I would never recommend anyone to wire sockets in 1.5mm. Surely this is a recipe for trouble, especially as people are using higher and higher power appliances (usually at the same time as they all try and dry their hair!). Therefore I always recommend that people wire to the safest possible standard and not the lowest common denominator.

I did do a typo on the size of the MCB and you are right that 20A is recommended.

 

[Punch]

[quote]Dear Paul With greatest respect I beg to differ. Under the latest release of NFC 15-100 it is recommended to install 2 circuits. One (Rangée inférieure) using a type A RCD and one (Rangée supérie...[/quote]

With greatest respect I beg to differ. Under the latest release of NFC 15-100 it is recommended to install 2 circuits. One (Rangée inférieure) using a type A RCD and one (Rangée supérieure) using a type AC RCD. I have checked this recently with my Legrand rep and he concurs.

Yes, this may be a recommendation perhaps, but it is not a SEPERATE fuseboard is it which is what you said in your original post. Actually working on real life installations for a living, it is not practical to be carried out where there is only one circuit that requires the type A RCD, (whereby you wouldn't use a whole row of a tableau electrique for just one disjonteur). It actually does'nt matter where the RCD is placed in the fuseboard or tableau as long as the protection is there. Type A are only obligatory in new installations carried out after June 2004 (from memory), anyway and we have had Consuel inpections that allow the AC type.

I would never recommend anyone to wire sockets in 1.5mm. Surely this is a recipe for trouble, especially as people are using higher and higher power appliances (usually at the same time as they all try and dry their hair!).

Oh dear!

This is totally allowable and has been included in the new French regulations and has been allowed probably due to the reasons I stated in my earlier post about such situations where sockets are commonly used for lighter appliances. Look at regulation 771.533 of NF C 15-100. You have to remember that the wiring is protected by an adequate size fuse or disjonteur and that heater circuits are wired seperately in France, so your comment about hairdriers etc; is unfounded. The same could be said for any circuit -if you plug in a heavier load then, if the wiring is adequate, the protective device will take care of the overload.

I'm sorry if you can't get it into your train of thought that French regs are different fromUK regs, and this new regulation if applied correctly is a very welcome addition to the regs. Considering the maximum number of 2.5mm wires in a 20mm gaine is three, then this regulation certainly helps the problem of too many gaines at the tableau.

I hope this explains it more fully, I would prefer to carry out my installations to the regulations rather than misguided inforlmation from a sales rep.

I hope you take this in the spirit it is meant as I would like to clarify what the actual regulations are and not just on individual hearsay or comments.

With Kind regards,

Paul