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[Clive P]

Good evening Gents and Ladies,

Having recently retired, thought it was time to put my own house in order. I spend a lot of time doing work for friends and family ( all free ) wiring and other jobs ( as you know us Electricians gather quite a few skills in our working lives ). So I thought it was time I updated my own electrical installation.
TN-C-S usual readings , 10 circuits nothing out of the ordinary. I'm looking at replacing the CU ( 16th ) and some minor rewiring ( dare I say it, upstairs lights are twin ). Been looking at the CU and as it's my own place, I'm thinking to myself what shall I go for; 17th board with twin RCD's, RCBO's or SP S/N RCBO's or something which I design myself.

The question is, it's your property, you want to do the best you can for safety and maintenance and all the other issues that come to mind.
What would be your choice? ( I'm pretty sure I know which way I will go and will post this when I see what you have to say ).

Regards.

 

[Clive P]

Hi,

Thank you all for your replies. As I said I would post what my preferred option is and that is to use SP S/N RCBO's. I know they are expensive, but as I don't have a major upgrade to do the cost isn't prohibitive. I will let you know how I get on with costs and other factors.
I just have to find a board big enough, 22 ways. Probably be Hager as well as that is what I prefer.

Regards.

 

[DPG]

22 circuits? Really? Daz

 

[Silly Sausage]

22 circuits? Really? Daz

Either lives in a BIG house or taking Division of circuits to a higher level.
I doubt if I got more than twice that number of points in my whole house!

 

[Octopus]

In the OP he refers to 10 circuits!

 

[davesparks]

Good grief people!

He states 10 ccts in his first post
Then says he is going to fit DP RCBOs so will need a 22 way board. No decent brand has yet come up with a single module DP RCBOs so we have to assume double module devices. So 10 circuits requires 20 ways, plus 2 spare ways.

 

[DPG]

I though he was fitting SP RCBOs? Daz

 

[davesparks]

In post number 16 he states that his preferred option is SPSN RCBO's.

 

[Clive P]

Hi,

22 Ways, that's 10 circuits plus main switch as correctly identified by some.

Regards.

 

[davesparks]

It is advisable to have some spare ways in there for future expansion, in fact i'm sure there is a regulation somewhere that says you should.

:rant:

Now the whole idea of consumer units being advertised as being 22 ways when you can only use 20 because of the main switch really winds me up, CU's have a main switch, or if not them something else in that position occupying those two ways so to even consider those ways in their description is ridiculous! Especially when they are supplied with main switch, if you were just buying an empty enclosure and supplying everything else separately then fine but otherwise wtf?
If you order a DB from someone like MEM where the incomer is a seperate item they don't go counting the two spaces for the incomer in their descriptions, so why do it with CU's?
:rant:

 

[Clive P]

Hi,
The configuration does include a spare way, and Yes I do agree with what you have to say about incomers etc.

Regards.

 

[Engineer54]

Good grief people!

He states 10 ccts in his first post
Then says he is going to fit DP RCBOs so will need a 22 way board. No decent brand has yet come up with a single module DP RCBOs so we have to assume double module devices. So 10 circuits requires 20 ways, plus 2 spare ways.

Schneider do a 1 PH + N single module RCBO that is you could argue, in most cases will be as good as a DP RCBO.

To be honest, i've found very little difference in the reliability stakes of RCD devices between the so-called Budget/Mid Range brands and top end brands. I personally wouldn't totally rely on any of them. And is why i'm a stickler that TN system ADS Zs values should be well ''Within'' OCD limits and not close or at max values. For TT systems, an additional upfront S type RCD should cover any downstream RCD device not tripping on a fault...