Compliance with 411.3.3 RCDs on Socket Outlets

10 mA RCDs can be used for compliance with Regulation 411.3.3 of BS 7671, provided the RCD complies with one of the standards listed in Regulation Group 531.4.1.

What standard do the socket-outlets incorporating RCDs comply with? If it's BS 7288, then  Regulation 531.4.1 does not recognise that standard for RCDs, and therefore removing the device at the origin of the circuit means the circuit would not, technically, comply with BS 7671.

As a further consideration, is the RCD required for other purposes (e.g. certain requirements for special locations in Part 7, or Regulations 522.6.203 / 522.6.204)? If so, it's likely that the circuit needs to be protected, not the socket-outlet.

I can not see a reason for removing RCD protection (RCBO in this case) from the circuit. I do not see a problem with having 10mA RCD protection at each individual outlet all on the same circuit.

The RCBO will protect the circuit and it`s wiring as required in BS7671 and you`ll also have some 10mA non BS7671 protection at each individual outlet. If any outlet is changed for a straight forward outlet then no problem either.

OK, let`s see what happens in an earth fault with an appliance. You have 10mA RCD (non standard) that would be OK in an ideal world with a non electrically leaky appliance and in theory would be more sensitive than the 30mA RCD. in a fault then both might trip or a very small fault only the 10mA might trip. As stated the socket 10mA inbuilt RCD will almost certainly not comply with BS7671 but may well give you a bit better protection. It could be a nuisance in some instances especially if your appliance has mains filters.

I would not remove the circuit RCBO but I might change some sockets to non RCD types if they cause problems. Otherwise I`d be inclined to leave them in place.

PS, you could change the sockets to inbuilt 30mA ones too. 

If , as stated, your RCD sockets are to BS 7288 then BS7671 says you can not rely upon them a the sole means of RCD protection where needed, it does not state that you can not have them

I would favour RCD/RCBO protection at the origin of the circuit AND use of socket outlets with inbuilt RCD protection.

The 10ma protection gives a greater degree of protection to a person handling a defective appliance.

Depending on circumstances, then 30ma protection is probably still required for the circuit.

RCDs do not have a great record of reliability, and two levels of protection give an extra safety factor. There is a chance that both RCDs may trip, but that in my view is a price worth paying.

Thanks for all the replies. The issue I have is the instruction has been to remove RCBO from switchboard, and only rely on outlet RCDs for protection.  Which I do not agree with. Happy to have either RCBO at DB and at outlets, or just on RCBO at DB, but not the scenario of no RCBO at the board and only socket outlet based RCDs.

Stick to your guns - I have no doubt that you will have the support of this forum.

Can someone remind me of the reason 7671 does not recognise 7288

Think it was because in 2015 BS7288 was updated. In it it said something like additional protection must be provided upstream of the device. Presumably additional protection was taken to mean an RCD by the JPEL committee, although it could possibly be argued it meant an OCPD. So we have the situation where a protective device needs another protective device, and it becomes unfit for purpose by default.

it said something like additional protection must be provided upstream of the device.

I understand it does, but the original wording I think was in a paragraph that was discussing the situation where the circuit upstream of the socket itself required additional protection (e.g. T&E concealed in walls) but it seems the clarity was lost during a revision. Why on earth the committee behind BS 7288 hasn't issued a corrigendum to make it clear again baffles me - they surely have manufacturers on the committee and an official interpretation that makes their products akin to a chocolate fireguard can't be in their best interests.

  - Andy.