Please Help With Crabtree Starbreaker Board

[cyberjunction]

Hi Guys
AS some of you may know I am fairly new to the trade and passed my elecsa assesment a couple of months ago.

I am in the process of doing my first install of a shower ( for a friend ) and need some advice.

Firstly I had to run the cable from consumer unit to outside wall and used 20mm plastic conduit for a 20m run on 6mm cable all outside as their extension just didnt allow for it internally. The problem I have is when doing the conduit calc it only goes upto 10m, amd I doing something wrong? Is 20mm conduit OK for this installation at this length ( a bit late now I know ) .

Secondly the Crabtree Starbreaker Split level unit has an RCCB 100ma on the left which is a time delay one with 2 light circuits on it and a couple of spaces. Towards the right there is a 30ma with 6 circuits on it. My problem is I need to rcd protect the shower but there is no where to put it so I see my options as follows;
1. Fit RCBO - expensive but easy
2. Add the mcb to the 30ma RCD by moving the RCD but is this possible, my training was on a standard dual rcd board so this is totally new to me. It seems the buzz bar goes right through from the left RCD right through to the right, I assume they are split but not sure then how I would add the MCB.

Appologies for the questions they may seem simple to most of you guys but I do not have the privledge of working with anyone and learning as I go. I want to ensure safety and learn the correct way,

Thanks Guys

 

[malcolmsanford]

As it will be the only likely circuit in that conduit I would not worry too much about it.

Anything is possible to be honest. I would move the RCD over to allow the fitting of the new MCB for the shower. Normally there would be 2 bus bars one for the lighting side, and one for the 30mA circuits. You should be able to buy lengths of bus bar to extend from the bottom of the last MCB, I often had small bits for this, and if all else fail you could loop across with a bit of 10mm cable.

6mm cable and 20 odd metre run, is that going to be man enough for the shower, I'm assuming it is an electric one rahther than a power pump type.

 

[nikmet]

On the crabtree board, the busbars are ready assembled one piece units, available in different splits, they are not adjustable, but 'for example' if the existing split was 6-6 you could purchase a 8-4 i think the busbars were about £10 each last time i needed to change one.

 

[nickblake]

id go for the rcbo option have alook on ebay you can get them quite cheap

 

[cyberjunction]

Thanks Malcolmsanford for the reply, I checked the cable calcs and is all good for the shower and the plumbing is already there as its an existing bathroom with high pressure so shouldnt be a problem, good job he's a mate !!

With regard to the RCD I was hoping I could move it over but couldnt see how the buzz bar is connected I seems its through the centre rather than the bottom, its just a lack of experience on my part and I am learning each day !!

Thanks very much for your reply, forums like these are a god send for us newbies ! cheers

 

[cyberjunction]

nikmet > this makes sense, many thanks

 

[SMB]

An RCBO is the easiest option here I would suggest.

 

[cyberjunction]

id go for the rcbo option have alook on ebay you can get them quite cheap

this seems the easier option but are they safe to buy from ebay? worried about cheap copies etc, only saying this because we told specifically not to buy them because of quality etc

 

[cyberjunction]

thanks to everyone who has replied so quickly, on this occaision I think I will go for the RCBO option but now understand the other options available, cheers

just to double check, there would be no issuses in putting this on the 100ma side as it will work independantly even though its going through the same buzz bar?

 

[SMB]

are they safe to buy from ebay? worried about cheap copies etc, only saying this because we told specifically not to buy them because of quality etc

You could have a good point there.

I think there is a forum sponser here that would beable to help you with the correct, and genuine, fitting.

 

[nickblake]

Cyber what size do you require i have a few left over from a job

 

[cyberjunction]

its a 40amp

 

[nickblake]

ill have a look see if i have a 40 Amp if i have you can have it mate

 

[malcolmsanford]

Yes you can fit the RCBO on the 100mA side of the CU as that will give you discrimination. Espicially as it is a time delayed type.

 

[cyberjunction]

Thanks Nick, pm me your paypal address if you have one and I'll cover your costs,