New build site RCD issues

[EFLImpudence]

It's different from the other, because the N terminals are on your right as you look at it.

I don't see the relevance.
The N terminals could be anywhere; they have no contact with the busbar.

Other brands I've seen also do that.
It would works just as well either way, but the labelling and colours (if any) would be incorrect and encourage errors.
On the Starbreaker, I don't know if it needs a special arrangement of those "stabbers" for the busbar, which other brands don't have.

I don't know what that means.

 

[JohnW2]

It's different from the other, because the N terminals are on your right as you look at it, and it's three units wide with offset terminals.

Well, the bottom N terminal is actual in the middle, but that's only possible because there are no L terminals as such (only 'prongs').

It would works just as well either way, but the labelling and colours (if any) would be incorrect and encourage errors.

What do you mean by 'either way' - that the power could be supplied to the RH 'prong' (i.e. if the main switch were on the right of the CU)? If so, I agree, but so what?

I don't see how anything you've said has a bearing on why they call it a 'split load' RCCB - as I just wrote, it could just as well be used in a single-RCD CU.

Kind Regards, John

 

[JohnD]

The N terminals could be anywhere

They could, but they aren't.

It's been consciously designed as L-N and the other is N-L

 

[JohnW2]

They could, but they aren't. It's been consciously designed as L-N and the other is N-L

I don't get what you are talking about. The L 'terminals' (prongs) are not to the left or right of the N ones (at the same level) - they're vertically in between the two N ones. I wouldn't know whether to call it 'N-L' or 'L-N' (well, I wouldn't call it either!).

Kind Regards, John

 

[JohnD]

let me think.

Is the difference that the "ordinary" RCD accepts the incoming connections as L and N cables into the terminals in the top, the outgoing L as a "stabber" and the outgoing N as a cable or solid bar; and the "split-load" RCD accepts incoming L as a stabber, and outgoing L as a stabber into a separate busbar, with a gap between the two busbars to prevent them touching?

 

[EFLImpudence]

It's been consciously designed as L-N and the other is N-L

No it hasn't. There are no L terminals except the prongs which are one on the left and one on the right on the back.


The formation of the CU depends where the gaps in the busbar are.

 

[AndyPRK]

Line connections are on the back as metal tabs which stab into the busbar.

View attachment 157354

That's the bottom of the RCCB

 

[JohnW2]

let me think. ... Is the difference that the "ordinary" RCD accepts the incoming connections as L and N cables into the terminals in the top, the outgoing L as a "stabber" and the outgoing N as a cable or solid bar; and the "split-load" RCD accepts incoming L as a stabber, and outgoing L as a stabber into a separate busbar, with a gap between the two busbars to prevent them touching?

Yep, I think that's about it.

... but, as EFLI and I have both said, that doesn't really explain why they've called it 'split load', since it could be used with other CU arrangements (well, at least one).

Kind Regards, John

 

[JohnW2]

That's the bottom of the RCCB

Most of that photo is of the back of the device. The bit at the very bottom of the pic is the bottom of the device (with the 'central' N terminal {on the bottom} visible).

Kind Regards, JOhn

 

[JohnW2]

Thinking about it, having to be 50% wider (i.e. 'taking up one more space in the CU'), to facilitate 'sitting over a gap in the busbar' seems to be quite a significant 'price' to pay for whatever advantages this device is meant to offer (sparing electricians the 'burden' of having to tighten an additional terminal screw or two?).

Kind Regards, John

 

[securespark]

The only thing I can think is that it is Crabtree's version of a "Stablok" HI board.

 

[ericmark]

It seems there are 13 versions of the 13 way Starbreaker consumer unit, it allows between 2 and 6 RBCO's and between 4 and 8 MCB's on first RCD and between 3 and 5 MCB's on the second MCB, it seems only item tested is the boiler, it would be very easy for it not to be a 513/226665B i.e. the configuration shown, it would be easy for an electrician fitting these units not to realise one what a different configuration.

Of course it could be just there is so little load, I know with my very old twin Wilex consumer units with a RCD feeding each one, it is common when resetting one for the other one to trip, never worked out why, but it has done that for last 20 odd years.

 

[skenk]

try disconnecting the neutral from the circuit which has the live disconnected