Replacement for star breaker RCCB which has failed.

Very slim I replaced my a few months ago at home. I did find a brand new one but you won't find a type A.

westward10 said:

Very slim I replaced my a few months ago at home. I did find a brand new one but you won't find a type A.

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Ah! Client not going to be so happy... new DB seems bit extreme

There is a way to fit a 2-module starbreaker RCCB into this, at least I managed it on an older board than yours. Crabtree technical advised me how to do this, so it is legit, though be warned that it is messy, and it may not be right for all installations.

You need a direct connection kit part number 100/DC1.

Remove the old 3-module RCD, leaving 3 newly vacated positions on the busbar, the middle being a blank (it was red on the one I did). The 100/DC1 plugs into the left position, and the new 2-module RCCB plugs into the right position, spanning across the middle position.

Now the messy bit:

Connect the line terminals of the 100/DC1 and RCCB together. Connect the outgoing neutral terminal of the main switch to the top neutral terminal of the RCCB. Connect the bottom neutral terminal of the RCCB to the neutral bar.
For this, I used 16mm meter tails. IIRC, it wasn't possible to get 25mm into the neutral bar, and was too difficult to work with anyway. Even using 16mm was a pain, and takes up a fair bit of room in the board. So your downstream circuits are limited to the 87A of the 16mm tails (not an issue if upstream fuse is 80A or less).

Technically, you could wire the neutrals to the RCCB the other way round, which takes up less space/is neater, however it leaves the RCCB with incoming line on one side of the RCCB switch, and the incoming neutral on the other. Crabtree advised against this.

Sorry, I don't have a photo of the finished job, but like I said, it wasn't pretty to look at. The RCD had become defective and needed replacing. They'd plastered the CU into an alcove in the wall (I think the room was a garage conversion), so replacing the CU would not have been easy.

Funnily enough I have this same issue coming up on a job, I wondered if you couldn't swap out the plug in busbar part for the equivalent one for both RCDs being 2 module ie the current one in the catalogue which has (I think) the same number of modules overall so should fit??
ps. my CU is the same as the OPs with 1 x 3 mod RCD and 1 x 2 mod with the newer type MCBs so not like the one in Pretty Mouth's post

grumpyjohn01 said:

Funnily enough I have this same issue coming up on a job, I wondered if you couldn't swap out the plug in busbar part for the equivalent one for both RCDs being 2 module ie the current one in the catalogue which has (I think) the same number of modules overall so should fit??
ps. my CU is the same as the OPs with 1 x 3 mod RCD and 1 x 2 mod with the newer type MCBs so not like the one in Pretty Mouth's post

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Would be a simpler option..... be interested to see what others think on this (watching)

This is the CU I'm dealing with, a 4+4 so by my reasoning, gaining a module on the LH RCCB gives a 5+4 so the busbar kit would be a 9265/DR. With the RCCBs being 363/A030, 63A fine for my application as there is a 50A device feeding the board.
(https://www.electrium.co.uk/media/vzhbqpci/crabtree-starbreaker-domestic-circuit-protection-2.pdf)
I'm at the quoting stage atm so would be interested if anybody thinks this won't work!
I might gather myself for a call to tech support if the job looks like it's going ahead.

grumpyjohn01 said:

This is the CU I'm dealing with, a 4+4 so by my reasoning, gaining a module on the LH RCCB gives a 5+4 so the busbar kit would be a 9265/DR. With the RCCBs being 363/A030, 63A fine for my application as there is a 50A device feeding the board.
(https://www.electrium.co.uk/media/vzhbqpci/crabtree-starbreaker-domestic-circuit-protection-2.pdf)
I'm at the quoting stage atm so would be interested if anybody thinks this won't work!
I might gather myself for a call to tech support if the job looks like it's going ahead.

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I asked crabtree similar, with a view to fitting RCBOs rather than an RCCB. They did say that the busbar could be changed for one without a split, so I see no reason why you couldn't fit one with splits. Give crabtree an email, they're quite helpful.