Discuss Split load dual RCD in the Electrical Forum area at ElectriciansForums.net

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Nolnoc

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Please excuse my ignorance but what is a split load dual RCD,or a split board.

Don't slate me I'm based in Ireland.We use RCD's and RCBO's.

I'm just curious.
 

SKY

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A split load board is a consumer unit normally split in half (but in the same enclosure) if it was a ten way board you would have 2 banks of 5 MCBs, Each set of 5 MCBs would be protected by 1 RCD (so 2 RCDs in total)
 

Fin170

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Generally

Split board, sometimes refereed to a 16th edition board, is a CU with a RCD protected side and a non-RCD (main switch) side. Sockets (and occasionally other circuits e.g. showers) would be on the RCD side of the CU and non-RCD (e.g. lights) protected circuits would go on the main switch side

Dual RCD, sometimes called a 17th edition board, is a board loaded with two RCDs (+Main switch) and the majority of circuits distributed between them (as 17th edition regs require just about everything on RCD due to burying less than 50mm, in domestic anyway). For discrimination purposes Upstairs lighting+downstairs ring will be on one side and downstairs lighting+ upstairs ring, this is also so if one RCD trips you should still be able to see on that floor.


Personally I still like to use a split board with additional RCBOs to allow for better discrimination but keep the costs lower than a full RCBO board.

Hope that helps but by the time I've typed this somebody will of probably come up with a better explanation :builder:
 

ruston

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Why do the wholesalers still sell them when to adhere to the 17th were using dual rcd boards
It will depend on the installation requirements , some circuits will not require rcd,s if the wiring is in trunking , conduit or otherwise protected ;to keep answer simple because it's getting late lol.
 
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Nolnoc

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Thanks a lot interesting.I would have thought RCD on lighting would cause a lot of nuisance tripping low voltage lighting etc,but I must be wrong.I don't do domestic work but as far as I know in Ireland,lighting cct in bathrooms and external lighting now need to be rcd protected,along with sockets and showers which always needed rcd.I think a lot of guys are just fitting a rcbo on every cct.It seems a bit overkill to me,but I'm open to contradiction..
 

ruston

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Thanks a lot interesting.I would have thought RCD on lighting would cause a lot of nuisance tripping low voltage lighting etc,but I must be wrong.I don't do domestic work but as far as I know in Ireland,lighting cct in bathrooms and external lighting now need to be rcd protected,along with sockets and showers which always needed rcd.I think a lot of guys are just fitting a rcbo on every cct.It seems a bit overkill to me,but I'm open to contradiction..
Yeah one of the new regs is if cables are less than 50mm deep or are not mechanically protected they must be protected by a 30ma rcd. Make of that what you will lol.
 

SKY

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I don't find lighting nuisance trips RCDs - they normally trip the MCB.
RCBOs are slowly becoming cheaper so I feel that within a few years a 10 way RCBO board will be about £80-£90 which with the benefits of not taking out 5 circuits in the event of a fault will work out better for all.
They just need to give us more head space in CUs
 

Strima

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I don't find lighting nuisance trips RCDs - they normally trip the MCB.
RCBOs are slowly becoming cheaper so I feel that within a few years a 10 way RCBO board will be about £80-£90 which with the benefits of not taking out 5 circuits in the event of a fault will work out better for all.
They just need to give us more head space in CUs
That'll probably come out in the next edition.
 
G

Guest55

A split load board is a consumer unit normally split in half (but in the same enclosure) if it was a ten way board you would have 2 banks of 5 MCBs, Each set of 5 MCBs would be protected by 1 RCD (so 2 RCDs in total)
Got your facts mixed up there sky.
All mcbs protected by 2 rcd's is a dual CU , split load has only 1 rcd plus a bank of unprotected ways
 
E

Engineer54

Both the so-called 16th and 17th CU's as well as stupidly called ''High Integrity'' CU's are all but compromises for a standard full RCBO CU, which should whenever possible always be installed. The above RCD CU's are a throw back from the day's before RCBO's. What's more, there is nothing like, or more suitable than a RCBO CU, to give you all the ''high integrity'' you need... lol!!!

Those RCD CU's are still around purely because of cost. In reality they are/can be a real pain in the arse when you have a leakage problem that covers 5 or more separate circuits...
 

telectrix

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all installations should go back to the old EE red spot boards. never any problems with them. LOL.:30:
 
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