You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
Having moved recently I’d like to replace my aged fuse board with some RCD protection
I’ve had a couple of quotes from electricians. ( so not a thread about how can I electrocute myself)
I was thinking RCBOs rather than rcd and MCBs. One has quoted for split load rcd and RCBOs - is that sensible, i am only informed by google and would have thought it’s either rcd or rcbo but not both.
Any sparkies able to put me straight?
Cheers!
Not a sparkie, but having some RCBO in a RCD protected board gives you more "discrimination", i.e. makes it easier to diagnose faults.
I'd just go RCBO everywhere, it's only about £10 extra per circuit.
An all RCBO board is the best you can get. There are makes that are quite inexpensive, I think it was BG where we were paying £10 per RCBO, whereas Wylex were £25.
A split load board generally describes a board that has 2 RCD's with 4 (or so) circuit breakers attached to one RCD.
If your installation and appliances are in good condition, then it isnt a problem using that type of board, I've had mine fitted for 23 years, and it doesnt nuisance trip at all.
However, if you have a fault on, say the lighting, then it will take out the other circuits on that RCD too. They are a little bit cheaper, £70ish for the board and internals complete.
You can get a split load board with 3 or 4 ways that are not RCD protected. You can put RCBOs in those ways, but it doesnt seem to be a good design doing that.
RCBOS are the way forward, no point installing them with RCD's in a domestic environment, otherwise there is a chance that the RCD will operate before the RCBO and defeat the purpose.
You can get time delay RCD's that would only operate if an RCBO failed to operate but in a domestic installation this is very rare.
Thanks. Turin, that was my concern- main rcd trip. Hadn’t thought of time delay. Quote was via text so not many details. He said yes was rcbo but then said was split load Rcd board, guess id best try and confirm.
It's missing "track" in its name, but is this any use? (I googled as I hadn't come across RCBO before.)
https://www.consumerunitworld.co.uk/what-is-an-rcbo-and-how-does-it-work-330-c.asp
Cougar - thanks. I think I had got straight what a rcbo is vs rcd. It was the combo I was struggling with.
Seems there is one possible downside in that if something trips then everything goes down so you know quickly (if you are in) but if the fridge is separate and trips you might not notice for 12 hours or more.
Cost seems to be 50 percent more 500 for 16 way (4 spare) and 750 for rcbo
The effects of double RCD from the main RCD and RCBO essentially removes the advantage of an RCBO, where if there is leakage current that would cause the RCBO to trip, the remainder of the house should be unaffected.
Thats the disadvantage of using one or two RCD's even in a split board. Also if its replacing an existing board, then the installation "MAY" have commoned the neutrals, this means that the easy way to fix it is to put all of the lights on the same RCD. Resulting in loss of all lights the event of a trip due to leakage.
Time delay for domestic installations is a bit excessive. Just make sure that as part of the work the installer is going to test and issue results.
It was the combo I was struggling with.
It would confuse me too. Its usually an either/or thing. Might mean something like my hybrid board with two RCD groups, including most of the domestic stuff, Then some non RCD circuits for a few specific items. These are either on an RCBO or just an MCB depending on the use. Best of both worlds IMO.
Turns out it’s for dual rcd only.
It’s an existing installation so 12 circuits in situ 80s pvc wiring.
I had a split board single rcd and non rcd in old house and the number of unwanted trips was pretty few and far between. Could I regret going for a rcd dual in the new house rather than rcbo through nuisance trips but if stuff is then it needs rectifying anyway.
Dual RCD is better than single RCD.
The only thing you might experience is that a nuisance trip from one item, has an impact on other circuits, this could lead to a freezer/heating system being unavailable due to an incandescent lamp failing. Unlikely perhaps but the consequences could be a giant PINTA. If you experience issues with a dual RCD, then you could always remove it and fit a main switch and individual RCBOS.
There was a period where items like freezer/alarm/heating (single points of connection) were installed without RCD protection for this reason. But think this option has been removed now.
Are you in the Republics of England/Wales or Scotland?
If in the sunny southlands I beleive Part P/notification is needed for consumer unit change, in the frozen northern wastelands then that doesnt apply
Sunny south so am expecting lba notifications and part p
Because it's STW...