Waterproof rcd

[bouh13]

Hi
I’ve just purchased a waterproof rcd for my shed. There is no neutral bar and no earth. I can understand there being no earth but what am I supposed to do with the neutral wires?

 

[JohnD]

Please show some photos of what you have bought.

 

[ericmark]

A RCD measures the power in all live wires, with three phase line 1, 2, and 3, and maybe neutral if there is one, single phase it uses both line and neutral, it can't work without both.

 

[JohnD]

I suspect there is a terminal, but not a bar due to the type of enclosure, probably an insulated standalone.

 

[JohnD]

I think @bouh13 isn't coming back....

 

[JohnW2]

Hi
I’ve just purchased a waterproof rcd for my shed. There is no neutral bar and no earth. I can understand there being no earth but what am I supposed to do with the neutral wires?

An RCD without a neutral connection cannot possibly work, so I suggest you 'look harder'?

Do I take it that the circuit supplying your shed is not already RCD-protected (at the house end). If it were an RCD-protected circuit, you would not really need another RCD in the shed, the only advantage being that of 'redundancy' (i.e. in case the one in the house fails to trip when it should).

Kind Regards, John

 

[bouh13]

 

[bouh13]

Sorry was working away when I asked the question got home and this is what I bought

 

[oldbutnotdead]

Well that's a shoddy looking thing.
First problem- you appear to be installing a consumer unit. Such things are required to be metal nowadays.
Second problem- you've bought some safety -critical kit from Wish or somewhere similar? Was it that much cheaper than trotting down to Screwfix or similar and getting a garage CU?
You'll need a multimeter to determine for certain what does what- it is likely that the terminal above the TEST button is N, the bottom 2 small terminals might both be N or might not. Are there any markings on the cable entry faces?

 

[JohnW2]

You'll need a multimeter to determine for certain what does what- it is likely that the terminal above the TEST button is N, the bottom 2 small terminals might both be N or might not. Are there any markings on the cable entry faces?

If what we can see were all there is (by way of terminals) it would make absolutely no sense. As I implied before, to function as an RCD, it simply must have four terminals - L & N 'in' and L& N 'out'.

The implication would seem to be that there must a a fourth terminal 'somewhere', but why on earyh would they' hide' it, rather than putting it in the 'obvious' place?

Kind Regards, John

 

[EFLImpudence]

Are you realising that this is one piece?

Meaning that there are 'enough' terminals (too many???).

Plus - does the C40 mean it is in fact a (single pole???) RCBO?

 

[flameport]

The unmarked terminal is an internal connection.
The other devices are separate and unrelated.
Type AC RCD which is not permitted
GB10963.1 is a Chinese standard.
The enclosure may be plastic but that is not 'waterproof' by any stretch of the imagination.

A UK compliant item with the required busbar, terminals, metal enclosure and Type A RCD is £33, https://www.toolstation.com/axiom-garage-consumer-unit-type-a-2-way/p75358

 

[JohnW2]

Are you realising that this is one piece?

Ah No, I obviously was not noticing/realising that! Thanks for making me look properly!

In that case, as you say, if anything there are 'two many' terminals, and I therefore am inclined to agree with what oldbutnotdead said - namely that the terminal above the test button is an N, as presumably are the pair at the bottom-ight (and, by implication the terminals at top and bottom of the part that looks like an MCB are the two Ls

Plus - does the C40 mean it is in fact a (single pole???) RCBO?

It does look like that and, although I do not find the diagram on it very clear, it looks as if that probably confirms that it is only SP.

... and why, I wonder, do all the devices appear to be C-curve? One has to hope that the circuits the OP intends to use it for will have a low enough Zs to support that.

Kind Regards, John

 

[JohnW2]

The unmarked terminal is an internal connection.

What you have indicated and say above seems credible (and different what what I had suspected).

Do I take it that you are familiar with the device and/or have seen its documentation, or are you just 'guessing'? ( without taking a meter to it, guessing is all I could personally do).

Kind Regards, John

 

[flameport]

Not seen that exact one, but have seen similar items before. They are typically sold for use in caravans and motorhomes on places like Aliexpress.

It's effectively an RCBO, but the MCB and RCD are separate items, overcurrent trips the MCB, current imbalance trips the RCD, but resetting one has no effect on the other, which is why the RCD has both test and reset buttons.