Discuss RCD Protection for submains in the Electrical Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

TJC1

-
Reaction score
6
Evening all

We have been asked to do some redial work picked up by a testing company i a hostel. It has been picked up that is no RCD protection in the rooms

There are 5 submain circuits that feed the 20 consumer units, 4 consumers units per submain (B32) Each room have a consumer unit which has two double sockets off a 16a radial and a lighting.

They asked my advice on whether to change the submain MCB to RCBOs or whether to change the consumer units for main switch and RCBOs

They supply cables to each consumer unit are above a plasterboard ceiling but cant be sure of the installation method, does the submain need to be RCD protected? As i dont want to put RCBOs on each circuit and also on the submain also

Thanks
 
If the installation method of the sub-main requires RCD protection then how will fitting RCBOs on the final circuits protect the sub-mains?

That's my question, do the submains need to be RCD protected? Seems ridiculous that i need to install an RCD on the submain when it protects 4 consumer unit. It would be much better to be able to install separate RCBOs on the consumer unit and leave the submain.

Does above plasterboard ceiling count as buried? Or require an RCD
 
Seems to me, that you have been asked to supply RCD protection for the rooms.
I’m assuming that’s for socket-outlets and circuits of locations containing baths or showers?
You can either install an up front RCD for each room, or swap MCBs for RCBOs.
How you do that is up to you.
 
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.
 
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.
 
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.
 
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.
 
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.
 
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 ?
 
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.
 

Reply to RCD Protection for submains in the Electrical Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock