RCD Requirements minor works

[Stspark]

Interested in fellow sparks opinions on this.

Client of a 15-20year old commercial/Industrial premises wants an additional 13a socket outlet installed for a specific piece of equipment, the additional wiring for this will be off a current non-rcd ring (with satisfactory Zs value) and installed not buried less than 50mm in walls.
The ring main currently supplies about 15 socket outlets for general purpose and electronic equipment. The earth leakage on the circuit is likely too high for an rcbo to be installed at db without nuisance tripping. The db has no spare ways to split the circuit into smaller radials or with a bit of rewiring smaller rings.

Bearing in mind there is no rcd protection for the entire circuit, will labelling of the additional socket outlet for a specific item of equipment suffice?

I've usually always found a way to improve the whole circuit and install rcbo at source for minor works however I don't think its reasonable in this situation.

 

[westward10]

Labelling a socket to me is a pointless exercise and what would you deem this specific item of equipment to be. A risk assessment is required with acceptance from your client that additional rcd protection will not be provided. You could fit an rcd socket but I see this as pointless seeing as none of the rest are rcd protected.

 

[Ian1981]

The regulations give 2 options for omitting rcd protection to a socket outlet
Not sure option b requires a risk assessment

(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.


The exception in indent (b), relating to the omission of RCD protection for specific socket-outlets, is included in both the current and new versions of the regulation.

It is stressed that the exception may only be applied for a socket-outlet that has been provided for the connection of a particular item of equipment. The socket-outlet must be labelled or otherwise suitably identified so that users will be clearly informed that the socket-outlet is intended only for plugging in that particular item of equipment and for no other purpose. Unless the electrical installation designer is convinced that the socket-outlet cannot reasonably be expected to be used for other purposes, RCD protection for that socket-outlet should not be omitted.

Both options look like they are being dumped in the new 18th edition so if your gonna do it,
Do it while you can

 

[Ian1981]

i do feel we have had this thread before tho

 

[Stspark]

I'm sure there's been similar too..

Yep, with 18th round the corner this type of situation could end up being a costly additional socket.

 

[westward10]

Commercial is not so much a risk as domestic as it is not the socket which creates harm but the appliance using said socket. Commercial duty holders are required by law to ensure appliances are safe and fit for purpose which should limit hazards.

 

[Deleted member 26818]

To start with, unless the installation is agricultural/horticultural or the circuit passes through a zone or supplies equipment in a special location there is no requirement to provide RCD protection for socket circuits.
Either install an RCD socket, or label the socket.

 

[Ian1981]

Additional protection provided to all socket outlets upto 20 amps and mobile equipment upto 32 amps for equipment outdoors is the actual requirement.
With 2 exceptions already listed

 

[Deleted member 26818]

Yes as I said, there is no requirement for the circuit to be provided RCD protection.

 

[westward10]

Ding ding

 

[Toneyz]

i do feel we have had this thread before tho

Makes a change to the one about a detached outbuilding.

 

[Ian1981]

Makes a change to the one about a detached outbuilding.

Well you've gone and said it now!

 

[Toneyz]

Well you've gone and said it now!

I'm not an electrician but I am running a 1.0mm cable to my shed for a welding set now my question is do I need a earth rod ?.

 

[Toneyz]

sorry I've gone off topic must be turning into Pete and Tel.

 

[Toneyz]

Back to the thread ..I the socket was behind the item of equipment and not readily accessible label it. If there is a likelihood that it could get used then fit a rcd socket as said risk assessment.

 

[Andy78]

If it really is for a specific item then chop the plug off and connect it into a FCU

 

[Toneyz]

Back to the thread ..I the socket was behind the item of equipment and not readily accessible label it. If there is a likelihood that it could get used then fit a rcd socket as said risk assessment.

What is dumb regarding the above disagree maybe please explain.

 

[telectrix]

What is dumb regarding the above disagree maybe please explain.

i wondered that.

 

[westward10]

I have noticed a lot of the "dumb" posts and the like come from the ghost watchers.

 

[telectrix]

 

[Ian1981]

I have noticed a lot of the "dumb" posts and the like come from the ghost watchers.

Agree I've had a few
And I didn't even know they've met me

 

[David M]

What is dumb regarding the above disagree maybe please explain.

The only thing that is dumb is the choice to press the dumb button
As expected, childish acts and miss use of forum tools. Most likely from folk who know nowt about electrics.

 

[Deleted member 26818]

Shouldn't be a dumb button.

 

[westward10]

Shouldn't be a dumb button.

Agreed I did complain about this initially but it fell on deaf ears.

 

[Andy78]

Shouldn't be a dumb button.

I agree. Should be swapped for a thanks button

 

[Toneyz]

Thanks guys for the posts I have no problem if someone disagrees and would do something a different way as I may say yes not thought of that for example. but I get annoyed when people puts dumb without a counter argument.

 

[static zap]

...... chop the plug off and connect it into a FCU

...to the added confusion of PAT tester with said item on his list !

 

[Rpa07]

I think the dumb button gets pressed accidentally when scrolling on a phone or tablet. It's in the wrong place for a 'right hander' - left handers would always press the 'like' button by accident and no one complains about that, do they!

 

[Generator]

just a 'technicality' query - the regs are not retrospective, so the existing circuit
(assuming it was installed pre RCD days) does not have to be RCD'd. Would fitting
an RCD socket therefore comply with current regs? ( Just curious! ).

 

[Ian1981]

just a 'technicality' query - the regs are not retrospective, so the existing circuit
(assuming it was installed pre RCD days) does not have to be RCD'd. Would fitting
an RCD socket therefore comply with current regs? ( Just curious! ).

Yes as your installing a socket outlet with rcd protection.
the work you undertake must comply with the current edition of bs7671

 

[telectrix]

Yes as your installing a socket outlet with rcd protection.
the work you undertake must comply with the current edition of bs7671

but if you are feeding that new socket with cable buried in wall <2" deep, then 522.6 needs to be complied with.

 

[Ian1981]

but if you are feeding that new socket with cable buried in wall <2" deep, then 522.6 needs to be complied with.

Cables not directly in a wall according to the OP.
Threads a week old I think so can't Remember