RCD Protection for submains

[Nigel]

I have just re-read the op.

The EICR that was done has highlighted a lack of RCD protection on final circuits on all CUs.

The client is trying to cut costs by asking if fitting ‘up front’ RCDs on the sub-mains instead of the CUs therfore installing five RCBOs rather than 40.

This is not an option due to selectivity so I would say no to that.

 

[Deleted member 26818]

Im not sure on the depth and the cable is T&E

If the cables are just laid on plasterboard, there’s no requirement for a minimum depth.
The drill through the plasterboard, the drill will push the cable away.
Where cables run through joists or battens, the drill can’t push the cable away, so additional protection is required.
1.Depth between cable and the surface of the floor or ceiling has to be greater than 50mm.
2.Earthed sheath, conduit or trunking.
3.Steel plate between the ceiling/floor and the joist/batten.
Unlike for cables concealed in walls, RCD protection is not an option.

 

[Bait Account]

My take on this is that if it was installed to the 16th edition or before then the sockets don’t require the additional protection unless they could be reasonably expected to be used for outdoor equipment.

 

[Deleted member 26818]

My take on this is that if it was installed to the 16th edition or before then the sockets don’t require the additional protection unless they could be reasonably expected to be used for outdoor equipment.

Yes, that’s correct.
Only started needing RCD protection when the 17th came in, as they would be used by unsupervised ordinary persons.

 

[Bait Account]

The thing is we don’t know when it was installed. We also don’t know if the guy who issued the report is aware of the changes between the 16th and 17th. My point is that I’d like to know these facts before banging in RCD’s.

 

[Deleted member 26818]

The thing is we don’t know when it was installed. We also don’t know if the guy who issued the report is aware of the changes between the 16th and 17th. My point is that I’d like to know these facts before banging in RCD’s.

Personally, If I’m asked to provide RCD protection, the age of the installation doesn’t matter.
I’ve done some work for a customer who owns a Cafe.
Installed a split load board a few years back, installed a new circuit for his dishwasher, installed some 600mm X 600mm LED lights, and a few other things.
Not all at the same time, but over a period of years.
The latest was to swap out the innards of the split load board and replace with RCBOs.

 

[45140]

The client may well have done a risk assessment and the remediation is the provision of RCDs given it is a hostel, so surely the basis upon which it was wired is hardly relevant ?

The correct solution would be an RCD for each room for obvious reasons and is surely the right answer ?

 

[Bait Account]

The client may well have done a risk assessment and the remediation is the provision of RCDs given it is a hostel, so surely the basis upon which it was wired is hardly relevant ?

The correct solution would be an RCD for each room for obvious reasons and is surely the right answer ?

We don’t know that bud but it is possible. It’s also possible that the person that carried out the report wasn’t aware of the requirements of additional protection in the previous editions of the regs. Anyway we can speculate all night as I doubt we’ll ever know the full facts.

 

[Toneyz]

The answers you seek are in BS7671

In that case my preference would be RCBO's to each circuit.

 

[westward10]

When I do EICRs I am not overly interested when it was installed with regard to additional protection it is a statement of fact it is not provided.