17th or RCBO DB?

ash_s3 · Dec 28, 2014

Just wondered what people's thoughts are on this.

Got a nice little board change to do, appeared to be your usual Wylex 3036 6 way, but the property only has 3 circuits Cooker, Ring final, and Lights (1bed flat)

Would you install a small split load 17th board like a 6 way BG (3+3) or go with a main switch enclosure with RCBOs? Cost is about the same, maybe RCBO option a few quid more.

Im swaying towards the RCBO option but it makes future upgrades more costly with the price of RCBOs over MCBs.

Cheers

Guest125 · Dec 28, 2014

Leesparkykent said:
Yes I would use them on TN systems as well, belts and braces.

In my opinion there is no need for RCBOs as you can split the circuits appropriately over a split load RCD board. This leaves the home owner with a range of options going forward. To be honest there is no wrong answer. Although do all the circuits absolutely need to be RCD protected?

Guest125 · Dec 28, 2014

Do all circuits actually need RCD protection?

uksparks · Dec 28, 2014

RCBOS do cost more so that is a factor in which way you go with it.

trev · Dec 28, 2014

UKESRail said:
In my opinion there is no need for RCBOs as you can split the circuits appropriately over a split load RCD board.

3 circuits in a 1 bed flat?

Guest125 · Dec 28, 2014

Yes the sockets need RCD protection. But if all the other circuits are in surface trunking then they do not need RCD protection. If they are buried in the wall at a depth of less than 50mm and not in an earthed steel conduit then they will also need RCD protection. No need to put RCDs if they are not required.

Guest125 · Dec 28, 2014

trev said:
3 circuits in a 1 bed flat?

Yes because you would make sure the lights and sockets were on different RCDs.

Risteard · Dec 28, 2014

UKESRail said:
But if all the other circuits are in surface trunking then they do not need RCD protection.

Bathroom light?

Guest125 · Dec 28, 2014

Risteard said:
Bathroom light?

Sorry you are correct. Circuits within a bathroom to. This includes circuits just passing through.

Leesparkykent · Dec 28, 2014

Main switch board and 3 RCBOs is going to cost about 60- 70 quid, Hardley going to break the bank isit compared to the price of a dual RCD board. And as for saying lights and sockets on separate rcds obviously this Is going to be achived with the RCBOs.

ash_s3 · Dec 28, 2014

All wiring is buried at a depth less than 50mm. If I were to split the circuits up over a split load dual RCD board I'd put the sockets on one RCD and lights and cooker on the other.

A split load board just seems a bit ott in this situation.

A BG 3+3 board can be had for less than £50 with the vat, 3x RCBOs and a main swith DB will be looking at more like £70-£80

kingeri · Dec 28, 2014

Why look for reasons not to RCD protect circuits these days?

Guest125 · Dec 28, 2014

kingeri said:
Why look for reasons not to RCD protect circuits these days?

Because that is what makes us electricians. Designing circuits correctly. Why would you want to put RCD protection on a lighting circuit unless you had to. Everytime a lamp goes the RCD trips. Great design there. With that sort of attitude you may as well say why not wire everything in 4mm SWA. Just to be on the safe side. Only a lazy electrician would say 'just RCD everything'.

uksparks · Dec 28, 2014

UKESRail said:
Why would you want to put RCD protection on a lighting circuit unless you had to.

You say it in a way that it comes across like its a pain in the --- putting it on an RCD? surely if you are testing the circuit properly as you should then why not just bung it on an RCD? Its either a compliant circuit or its not.

UKESRail said:
Everytime a lamp goes the RCD trips.

Usually its the OCPD that trips due to the in-rush causing an overload, but i'll let you off. Not once has an RCD tripped on me when a bulb blows, think about it, the bulb only uses Live and Neutral....

UKESRail said:
Only a lazy electrician would say 'just RCD everything'.

I don't know, I don't say RCD everything and I am not lazy, but if I am changing a board, everything will end up RCD protected... as I either do 17th split or high integrity.