Consumer unit wiring pls help

[Lago Jardin]

Hi I live in Torrevieja near Alicante in Spain although i am from Leeds in the UK.

Our mains supply in our apartment is limited to 3.3 kw, this is very common here. Pretty obviously the supply frequently trips out when cook especially when in summer we have the air con on too. Its possible to upgrade the incoming supply to say 5.5kw or 8.8kw and pay an extra standing charge to Iberdrola. I am trying to get an electrician to do the upgrade but they have to Spanish in order to provide the correct paperwork for the legal upgrade.

Naturally I dont want to get ripped off. Many English electricians will do it illegally. The incoming mains is cartridge fused at the meter at 35 amps and the incoming in the consumer unit passes thru a 15amp 2 pole MCB then thu a 25amp breaker on the outgoing side (I think this is an RCD it is 2 pole with a test button). In turn this feeds two, 2 pole MCB (15amp for 8 sockets & 1 air con) and (10amp for 5 sockets, 7 lights & 1 air con). All kitchen power is on the 15 amp circuit. As they are radial circuits I dont know much about them I was OK with ring circuits in the UK

I have taken a digital photograph of the wringing in the consumer unit. I would be happy to email it to anyone that might be able to help. In particular, I dont understand why the incoming first passes thru a MCB and then a RCD. You really need to see the picture. I dont think that this News/g allows attachments but I will try.

I would be obliged if anyone could advise me on the work that is needed to upgrade to say about 8.8kw which would be my max short period demand. Any comments about the consumer unit wiring would be helpful.

If this is all boring or off topic please accept my apologies and just ignore all this but its really difficult to get objective advice here in Spain.

Thanks a lot

Nigel

[G&M]

Are you sure this upgrade is just for a fuse change as you suggest and not a change in wiring as well ?

I assume it is this one that trips ?

[Lurch]

On Mon, 03 May 2004 19:05:00 GMT, in uk.d-i-y "Lago Jardin" strung together this:

The MCB will be for the overload protection and the RCD will be for earth fault protection. The 25A rating on the RCD is a maximum and not an actual current limited by the device, the MCB does the limiting.

[Lago Jardin]

Hi

Thanks for the replies.

It is either the 15 amp MCB on the incoming or the 15 amp MCB protecting the sockets that trips. Obviously, I am just exceeding the maximum supply when using more than a couple of kitchen appliances (eg kettle, microwave etc). This is why I need to get it upgraded. 3.3 kw is pretty small really.

Thanks to Lurch for his reply. I understand now why they are using the 15 amp MCB on the incoming. and then the 25 amp RCD.

It looks like I need that MCB increasing to about 25 amp. The wiring is suitable but I think that the two radial circuit to the sockets that have the heaviest usage may need looking at if I went above 5.5 kw. The Spanish use all single strand cable (no twin & earth cable). I think that at present it is 2 x 2.5mm cable to the sockets but i am not certain as I can identify twin & earth much easier than single cable. I am not sure how the sockets are balanced on these circuits. I'd have to disconnect and test to find out.

Can anyone advise me on what cable size would be best for the radial sockets circuit. I presume that the cable goes around the apartment thru the conduit and then the sockets are "spurred" off it using connector strips. There are access points into the conduit via flush mounted plastic covers just below ceiling height, above all sockets.

Finally, I think that I really need to re-organise the consumer unit and may be try to get the incoming on one side and the outgoing MCBs on the other. At present they are all bunched together in the middle. Does that sound right? Where would I place the RCD?

I am not about to do anything until I know exactly what I am doing, for certain. If anyone has time to look at the digital pictures that I have taken then please ask and I will email them to you. I am sure that "one look" and it would be obvious what I should do to anyone with suitable experience.

The Spanish criticise UK ring main installations as unsafe but they are a lot easier to deal with and u don't get the trip outs that u do here because of the much higher incoming rating.

Thanks again for all the help

Nigel

[Lurch]

On Tue, 04 May 2004 09:43:25 GMT, in uk.d-i-y "Lago Jardin" strung together this:

If you wanted to squeeze the maximum out of the current wiring you could probably upgrade to a 16A breaker! You may be able to up it to a

20A but the cable run would have to pretty short and the ambient temperature would want to be lowish, 15C or thereabouts.

If it were my home I would use 4mm cable for a 20A radial and 6mm cable for a 32A radial.

Could be, best bet would be to open up the covers and take a peek. If you were renewing anything I would loop the cables through each socket rather than using connectors in the boxes.

If you want to you can, but as long as it's all connected up correctly and labelled appropriately then any order is fine.

Email address in header, send 'em in.

Bloody foreigners! ;-)