No RCD on entire installation

[sparky1508]

Enough room for an rcbo?

As above, no room for RCBO.
I have given the client his options and he has said he would like the sockets labelled for specific equipment. I know this does not have any safety aspect at all but he is the client and I can only do what he asks for.
Thanks for all the input and advice.

 

[Roofus]

From a different perspective: We don't install RCD's on circuits which have a number of servers due to tripping of RCD's etc. The servers power supplies filter out electrical noise which they dump to the CPC. So we cover this in our risk assessment and label sockets up for IT equipment only. You might want to check your earth cable is up to scratch for protective current flowing from servers and run additional earth cable if required.

 

[marc8]

No room for RCBO's, CU already chock full.
I think I will speak to the client and see which direction he wants to go. I am personally leaning towards putting RCD sockets on all 3 that I have worked on. But if he chooses a main switch RCD is that something that can be done with a 30ma.

if you look at the work you have undertaken on 3 sockets I would go for RCD protection local to the work you have undertaken, after testing the circuit you have joined on to. the reason for this if you put an upstream RCD in circuit & there is a problem on equipment it could trip & you could be blamed for the circuit tripping.
if circuit / circuits test out okay install a RCD socket outlet issue a minor works anything plugged in will trip your RCD socket only & not trip the whole circuit / circuits, at this point you have protected your work & covered yourself.

 

[marc8]

if you look at the work you have undertaken on 3 sockets I would go for RCD protection local to the work you have undertaken, after testing the circuit you have joined on to. the reason for this if you put an upstream RCD in circuit & there is a problem on equipment it could trip & you could be blamed for the circuit tripping.
if circuit / circuits test out okay install a RCD socket outlet issue a minor works anything plugged in will trip your RCD socket only & not trip the whole circuit / circuits, at this point you have protected your work & covered yourself.

& if for a server I would think twice about RCD protection as above post #42, I would tend to run in a new circuit for server & clean earth.

 

[Pete999]

IMO, he has made alterations to the circuit, at the very least the spured socket should be off a RCD FCU or up front RCD in closure for the circuit in question.

Or an RCD socket

 

[Taylortwocities]

Or an RCD socket

But that does not provide the required protection for the buried cabling.

 

[Pete999]

OK

 

[DPG]

If you fit a 30mA RCD up front of the dis board then you risk the whole lot tripping out on an earth fault. And if it's IT stuff in there then your total leakage current is going to be heading towards the trip current of the RCD anyway I would have though.

 

[Stspark]

I'd be looking to install rcbo's on the worked on circuits. Why do you say there is no room for this? Generally rcbo is only about 20mm longer than a mcb.
Other than that, instruct the client to provide a specific written risk assessment for the omission of rcd/rcbo on socket outlets circuits, which will need to be attached to the eic or mwc, good luck with that! Rcbo for me

 

[Taylortwocities]

Generally rcbo is only about 20mm longer than a mcb.

Many many legacy CUs just physically do not have a spare 20mm above the existing MCBs. Older ones often have solid neutral busbars and other obstructions that just make fitting an RCBO an impossibility.

 

[Stspark]

Many many legacy CUs just physically do not have a spare 20mm above the existing MCBs. Older ones often have solid neutral busbars and other obstructions that just make fitting an RCBO an impossibility.

Fair point. Thinking of options to keep cost at a minimum for client and maintain compliance. Utilise the other spare way in the cu, use 2 pole rcbo generally they're the same shape as an mcb? Bottom line is, an rcd is required unless a written risk assessment is provided.

 

[Deleted member 26818]

Fair point. Thinking of options to keep cost at a minimum for client and maintain compliance. Utilise the other spare way in the cu, use 2 pole rcbo generally they're the same shape as an mcb? Bottom line is, an rcd is required unless a written risk assessment is provided.

No documented Risk Assessment is required for sockets intended for specific items of equipment.

 

[Ian1981]

There's 2 options for omitting rcd protection.

(a) where, other than for an installation in a dwelling, a documented risk assessment determines that the RCD protection is not necessary, or

(b) for a specific labelled or otherwise suitably identified socket-outlet provided for connection of a particular item of equipment.

Obviously additional protection is still required for cables in walls etc etc

However these options look like they are being scrapped when the new 18th edition is in forced

 

[Taylortwocities]

As ian1981

I do not believe there is the option of a risk assessment for a domestic premises.

And I think that option b) will not be allowed when the 18th edition comes into force.

 

[Stspark]

When installing additional sockets to an existing non-rcd circuit with already a number of socket outlets with cables not mechanically protected buried in walls less than 50mm, in a commercial premises. For me 'Specifically labelling for a particular item of equipment' is not generally practical, as the socket outlets across the entire circuit worked on could be used for any number of purposes by employees or public. RCD or the risk assessment route clears up any confusion.