New sockets existing ring

[KNIPEX]

Hi all, ive been asked to add 2 extra socket to the ringmain in an office, the office is on a 32a mcb.

all cabling is surface so will i need an rcd/rcbo

if it was a new circuit i agree i would then need one, but do i need one for just adding sockets of existing circuit??

if yes this is going to push the cost up sky high and i will proberly then loose the job

 

[davelerave]

not sure on the UK rules -it's 30MA here automatically


but you need to be careful in an office environment of introducing nuisance with a single rcd/rcbo

 

[caddy]

Well that depends on what the sockets are going to be used for and who has access to them. If you look in the regs book and find that they do need to be rcd protected then you may be able to use RCD sockets.

 

[JUD]

411.3.3 RCD required unless the socket outlets are for use under the supervision of a skilled or instructed person or are labelled for a specific item of equipment.

 

[KNIPEX]

just to confirm this is an existing circuit which im breaking into.

 

[Sintra]

Your Additions still have to comply to bs7671 2008.

 

[tuckermot]

surface mount ( trunking or clipped direct ) i thought does not require rcd protection !!!

Rich

 

[GStueyXR]

Dont do the work until the new amendment of 7671, then you dont need to RCD protect

 

[SirKit Breaker]

Hi all, ive been asked to add 2 extra socket to the ringmain in an office, the office is on a 32a mcb.

all cabling is surface so will i need an rcd/rcbo

if it was a new circuit i agree i would then need one, but do i need one for just adding sockets of existing circuit??

if yes this is going to push the cost up sky high and i will proberly then loose the job

I am inclined to agree with Jud on this one to some extent. I aint going to go and get the book out but if my memory serves me correctly the cables dont need RCD protection as they are in trunking, surface mounted etc, but you would need to provide RCD socket outlets.

You say it will push the cost sky high......RCD's and RCBO's are coming down in price. Stick an RCBO in for the ring it will only push the cost up by about £30, cheaper than a handful of RCD outlets.

Cheers........Howard

 

[GStueyXR]

surface mount ( trunking or clipped direct ) i thought does not require rcd protection !!!

Rich

ALL socket outlets must be RCD protected. Unless skilled/instructed.

 

[tuckermot]

what new amendment is that ????

 

[JUD]

what new amendment is that ????

DPC BS:7671/AMD 1 - The IET

 

[mnmwill]

Wot about spur into RCD FCU?

 

[JUD]

Wot about spur into RCD FCU?

This could be the best option if there is a lot of IT equipment on the ring as high leakage currents could cause nuisance tripping of RCD/RCBO.

 

[tuckermot]

Hi jud

just been on the link makes very interesting reading ( additions /alterations on a 3036 fuse wire ) at the discretion of the electrician if rcd needed ( new socket near back door ) or socket in front room just need to fit rcd socket and not rcd whole circuit makes fitting a extra socket backt to £ 100.00 and not new board ect £ 350-500 roll on july 2011 and the big green book

Rich

 

[Deleted member 9648]

Although 7671 requires that all sockets rated at 32a or less must be RCD protected the get out clause is the line 'unless for use of skilled persons or persons under supervision.
If the sockets are to be used for specific equipment rather than general use and that equipment is supervised by say the IT manager.....in my opinion there is no need to RCD them. I also consider that in an office environment it is undesirable to RCD them as nuisance tripping can cause significant problems and disruption.
The sockets you install should be labelled as not RCD protected and not for general use

If the installation method that YOU use is surface trunking (regardless of the rest of the circuit)then RCD protection for the wiring will not be required,if you conceal cables at a depth of less than 50mm and not enclosed in earth metallic conduit etc then RCD protection will be required and this would probably mean in practice RCD-ing the whole circuit..

 

[ICE]

I will go with Jud