RCD protection on Office socket - Three phase board.

[highspark]

On a job at the moment and office sockets have no RCD protection. They are ran in singles, PVC conduit. I am adding onto the circuit as additional rooms are in the process of being built. Do I need to protect the whole circuit with an RCD or can I just protect the new sockets with an RCD FCU? Whats the score with three phase boards and RCD protection? Do I need to fit an RCBO?

 

[telectrix]

if sockets are under the supervision of a "skilled or instructed" person, then there is no requirement in BS7671 to fit RCD protection.

 

[highspark]

No skilled people. Just offices workers and a store room. Best way to RCD protect sockets? RCBO?

 

[telectrix]

any IT equipment on them?

 

[malcolmsanford]

No skilled people. Just offices workers and a store room. Best way to RCD protect sockets? RCBO?

Under the EAWR not only employers but employees are expected to know the dangers of electricity in the workplace and so I would say the office workers should come into at least the instructed persons category, as they should be instructed by the EAWR regulations and their employer

 

[RISElectrical]

In my experience of office fit outs etc working for several companies it has always been fine to not put on an RCD as the office staff etc are deemed instructed, as far as I remember this was something to do with the offices H&S that no staff should be touching anything electrical. Dont know how this would apply to smaller companies offices etc without strict H&S in place.

Could always fit an RCBO to be on the safe side, I probably would tbh. Then your covered either way.

 

[highspark]

Yes there is IT equipment throughout!

 

[RISElectrical]

Wouldnt bother with the RCD tbh then. Imagine the phone calls you would get when the IT server goes down because of nuisance tripping :-0

 

[highspark]

Going to put IT sockets on non RCD radial.... I need an earth going back to the board?? Then going to have seperate Circuit for other socket outlets for cleaners and hand tools in store room on rcbo?

 

[telectrix]

for the IT sockets, a radial is fine, but you need to install hi integrity earthing.

 

[highspark]

Not too sure where to go on this one....? What reg lets you get away with not RCD protecting sockets...other than the 50mm rule and also the under skilled occupation....Because I don't consider regular office staff as "skilled" Electrically..... I also though do not want a case of nuissance tripping.....Whats the best way to go in your honest opinions?

 

[telectrix]

you only need 1 "skilled" person ( manager ) in the office. all other staff can be "instructed" persons. i.e they are instructed by the skilled person not to mess about with electrical equipment.

 

[highspark]

So would this be noted on the EIC...."Under supervision of skilled person". Can you give the manager "skilled" status though?

 

[supasparxs]

On a job at the moment and office sockets have no RCD protection. They are ran in singles, PVC conduit. I am adding onto the circuit as additional rooms are in the process of being built. Do I need to protect the whole circuit with an RCD or can I just protect the new sockets with an RCD FCU? Whats the score with three phase boards and RCD protection? Do I need to fit an RCBO?

Are the conduits running surface or chased into the walls?
If everything is surface then no RCD's are require

 

[telectrix]

no reason why not. not all managers are numpties despite what we call them.

 

[highspark]

Are the conduits running surface or chased into the walls?If everything is surface then no RCD's are require

What about through ceiling spaces though? They are going to be dropped into PVC conduit from a ceiling space.

 

[spark 68]

The keywords are skilled or instructed, as others have said, EAWR requires staff at work to be informed via H&S policy.

So long as the cables are not buried in the wall, or being used outdoors, or in a special location, the RCD protection may be omitted.

Section 411.3.3

 

[telectrix]

even the 50mm rule in walls is out the window where skilled or instructed applies ... 522.6.7

 

[spark 68]

Going to put IT sockets on non RCD radial.... I need an earth going back to the board?? Then going to have seperate Circuit for other socket outlets for cleaners and hand tools in store room on rcbo?​

That is exactly what I would do too.

Re HI earthing, there is a good article covering this in the wiring matters mag (attached)​

 

[supasparxs]

no reason why not. not all managers are numpties despite what we call them.

I totally agree with you

 

[spark 68]

HI Earthing cont.

I need an earth going back to the board??

Here is an extract from GN8, for the final socket outlets, to be used in conjunction with the wiring matters article earlier.

This shows a bit clearer the connections required.

 

[Dunc]

RCD socket outlets is the way forward in my opinion. Not a cheap method but a single fault will cause only one socket to stop working and you're completely covered on the grey area of 'supervision by skilled persons'.

 

[cprfenom]

for the IT sockets, a radial is fine, but you need to install hi integrity earthing.

I know this is an old thread, but do you always install a high integrity earth to circuits supplying computers or do you check to see if there is 10mA to the cpc on that circuit first?

Also sockets on the same pillar that don't have PC's plug in would you consider RCD sockets?

I only ask because being a newer to the party than some here, I wouldnt trust employees to be considered instructed under the EAWR regs

 

[DPG]

Don't the latest regs say that, for commercial stuff, if an RCD is deemed not necessary then a written risk assessment needs attaching to the installation cert? Daz

 

[telectrix]

I know this is an old thread, but do you always install a high integrity earth to circuits supplying computers or do you check to see if there is 10mA to the cpc on that circuit first?

Also sockets on the same pillar that don't have PC's plug in would you consider RCD sockets?

I only ask because being a newer to the party than some here, I wouldnt trust employees to be considered instructed under the EAWR regs

regs. have changed. the skilled instructed personnel are history. to omit RCD ptotection now requires a written RA. most of us would now insist on RCD protection for all sockets <32A, and for cables in walls <50mm, for use in office/factory environments. consideration would need to be given to IT equipment , usually by ensuring < 10 items per circuit.