sizing of RCBO's for different make boards

Gavin John Hyde · Jun 8, 2017

I am looking at some rcbo's for a job im planning.

Does anybody have or know of a link to a list of the sizes for different makes of RCBOS and what boards they fit.

ie make A RCBO will fit CU makes x,y,z etc..

As it is a pain in the a**e with them always being different sizes...

I am installing a few new circuits in a house and will be using RCBO's but the CU has no manufacturer markings on it other than made in EU - and something i have discovered is czech... so have no idea who made the CU. the MCBS are all a mixture of wylex but there is quite a large space around them and clearly the mcbs and CU are different makes;

Any advice appreciated

Octopus · Jun 8, 2017

Post a picture of the CU................. would be my strategy..

Gavin John Hyde · Jun 8, 2017

Murdoch said:
Post a picture of the CU................. would be my strategy..

That will have to wait until next week when i go back to the house to fit some new sockets. im just browsing the forum whilst watching the election fiasco on tv. so thought id post the question in the meantime.

Octopus · Jun 8, 2017

nice new shiny metal clad CU?

westward10 · Jun 9, 2017

A protective device should be compatible with the enclosure. A picture would be helpful, cover on and cover off.

LankyWill · Jun 9, 2017

SBS compact rcbo's might be worth a look, they probably have the smallest footprint.

richy3333 · Jun 9, 2017

You shouldn't be mixing manufacturers parts. Most these days mention it in their destructions because they aren't tested with other manufacturers equipment, only their own. Hager and M2/Proteus state it I think.

That aside it always looks like a botch job and makes me wonder about the competence and work standards of the installer.

Deleted member 26818 · Jun 9, 2017

Consumer Units are a particular type of Distribution Board that has been type tested.
While the individual parts of the CU may only be rated to withstand lower fault currents, the complete unit is rated to withstand about 16kA.
If you install components from other manufacturers the type testing will be voided and you will have to ensure the withstand rating of the individual components is equal to or greater than the maximum Prospective Fault Current.

Gavin John Hyde · Jun 9, 2017

Problem solved i have got a used wylex CU metal body from another spark which he replaced on another job, it looks brand new still, i will move the wylex mcbs into the empty body, i will test the rcds and decide if i need to get some new wylex ones.
The RCBOS i am going to use will be wylex too so now do not have the issue of different brands. the RCBOS fit very good in the CU so it will look tidy too.

Only issue is that the customer is asking why i am not using the cheapest ones in the screwfix catalogue. i really hate it when the customer starts consulting their own copy and then they start looking at you funny as if you are ripping them off! i can not be the only person who hates it when the customer supplies the parts themselves as you can guarantee it will either be crap quality or dirt cheap and likely to fail sooner than the better made stuff.

richy3333 · Jun 14, 2017

Gavin John Hyde said:
Problem solved i have got a used wylex CU metal body from another spark which he replaced on another job, it looks brand new still, i will move the wylex mcbs into the empty body, i will test the rcds and decide if i need to get some new wylex ones.
The RCBOS i am going to use will be wylex too so now do not have the issue of different brands. the RCBOS fit very good in the CU so it will look tidy too.

Only issue is that the customer is asking why i am not using the cheapest ones in the screwfix catalogue. i really hate it when the customer starts consulting their own copy and then they start looking at you funny as if you are ripping them off! i can not be the only person who hates it when the customer supplies the parts themselves as you can guarantee it will either be crap quality or dirt cheap and likely to fail sooner than the better made stuff.

Why aren't you getting Wylex parts from your wholesaler cheaper than screwed fix? If it were me I'd give your customer a price for doing the job properly or just walk away. I see no reason why you have to be sourcing second hand parts if new ned are freely available?