paulven

Since your installation is protected from overload by the main circuit breaker and the individual circuit breakers, the RCD is protecting against earth leakage currents, so the significant value is the milliamp rating. I would recommend a new 40amp 30 milliamp RCD which you can get from Bricomart for about 11 euros.

Loco Pedro

So are you suggesting 40 amp because it is easily available and cannot cause a problem being a higher rating or is it simply a better choice ?
Our local Brico stock them at about 25 euros as I remember.

MikeJ

Beg to differ, my post #20 suggests a bridge megga test. It's probably the only definitive test.
Unfortunately there has been a lot of misleading advice about RCD current ratings. The only relevant rating for an RCD is on millamps
The only thing I can imagine is that these breakers being talked about are combination RCD/MCB devices.

Loco Pedro

OK, thanks for that.
So I need to find a decent Spanish electrician to run the bridge megga test.
How long does that usually take ?

Pulaski

That seemed clear to me from post #1. The fact that a device was referred to in Amps when RCDs have a trip threshold at the level of milli-amps makes that the only explanation, doesn't it?

Fredbargate

It would appear that there is a 25 amp circuit breaker followed by a 25 amp RCD
Therefore regardless of the amperage of the RCD so long as it is 25 amp or higher the the 25 amp circuit breaker will protect against an overload

Loco Pedro

You are correct.
Inbound live & neutral go to:
1. 25amp circuit breaker
2. 25amp/30 m/Amp RCD (combination ?)
3,4,5,6,7, - other circuit breakers.


So, is it desirable / necessary to have a higher rated RCD than 25amp /30 M/amp ?

lyric030250

It doesn't matter as long as it is rated at or more than 25amps that is just the current it can carry, the crucial figure is 30ma that is it's trip value.

Loco Pedro

For the avoidance of doubt, here is the consumer unit (if I have managed to attach it correctly) - and it appears that the RCD is connected by the live/neutral which are routed down behind everything and connect to the top of the 16Amp breaker which controls all the outside wiring.
I assume the RCD still acts as protection for the entire board and this connection is merely the means of combining all the breakers from both top and bottom rails ?

Fredbargate

Not the best of set ups with what appear to be bare wires hidden behind insulation stripped from a larger cable.

However I would guess from what I can see that the power is fed through the first 25 amp breaker and down to the 16 amp without it going via the RCD
The top of the RCD appears to be fed from the bottom of the 25 amp and then up into the top of the other 4 breakers with the bare wire I mentioned before, but there must be some insulation somewhere, and it is only these 4 breakers and their circuits that have RCD protection.
I may be wrong, anyone else with ideas?

A photo with the two random insulation strips removed would be clearer.

Loco Pedro

No, that is incorrect. But I realise it is difficult to see from my photo.
The live/neutral entering the 16 amp breaker on the bottom rail are coming from the top of the RCD. They are running down behind everything else.
I can see why you would think what you say. Its a trick of the photo / an optical illusion.
Hence my question - "is this just a means of combining the 2 rails for the 1 RCD" ?

missile

It appears you have a number of errors with that distribution board. This is not something a home owner should be meddling with. I would suggest you get a qualified electrician to review your installation.

MikeJ

Oo nasty! I'm afraid it looks like a DIY bodge which conforms to neither Spanish nor UK professional standards. If you ever want to sell you will have to get this rectified by a certified electrician - you may also want to get it done for your own safety and peace of mind, I'm not sure your insurer would be very happy either.

old.sparkles

Looks to me like the RCD is fed from the wrong side. I know this is an issue for some RCD's but not sure on the Merlin Gerin as couldn't find a data sheet (and not spending too long googling). In case it's not clear, looks to me like it's fed at the bottom using a section of the bus bar.

Descrimination is wrong - mains 25A feeds RCD 25A/30mA feeds 40A amongst others?

The connection rail (bus bar) isn't an issue though - could just be seated better. Also, all MCB's other than main switch are RCD protected. I've attached a pic of one not connected. Bus bar is feed MCB's on top rail, and singles are feeding MCB on bottom DIN rail.

Anyway, inclined to agree with other posters. Get another electrician out. Maybe split your circuits across 2 RCD's - an electrician can do this easy enough. There are two circuits in the 20A MCB in the middle of the photo. Probably a good idea to split these onto their own breakers. If you have more than one lighting circuit, and/or more than one circuit supplying socket outlets, split those across the two RCD's.

Not familiar with local regs but make sure any electrician you use is. Whilst they are splitting the circuits, they can test and label them all for you.

Fredbargate

Looks more like a selection of wires hidden behind a strip of insultion from a larger cable, than a busbar.
I can see two bare cables going into each fuse, there may or may not be some insulation on the hidden parts?