Discuss what size rated RCD to use as main switch in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net

J

jutty

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the whole C/U is covered by the RCD, what size RCD should be used?

thanks
 
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J

jutty

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  • #3
14 way board, 4 x 32 amp supplies, 4 x 16 amp, 5 x 6 amp and 1 x 2 amp

do i need a 100amp 30mA RCD
 
G

Grae79

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  • #6
work out ur max. demand...

why do you want everything on RCD anyway?
 
E

EasyFox

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  • #7
What is the service cutout fuse rated at ;)
 
S

Shakey

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  • #8
An RCD used as a main switch should be an S type, and i cant begin to tell you the regs you are breaking by using one RCD!!! Seperation of circuits to avoid inconvenience and danger? Smoke alarm not being on same RCD as sockets? (assuming theres one there!)

Just wondering why you would be doing this? Why not put a twin or triple split load in with two seperate RCD's and possibly RCBO (again assuming smokes) and sign it off on 17th edition paperwork!!!
 
E

EasyFox

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  • #9
An RCD used as a main switch should be an S type
On a TT system with a split board or if 2x rcd's run in series then yes I agree an S type should be used.

i cant begin to tell you the regs you are breaking by using one RCD!!!
Go on it would help those that dont know. The only one that I can see that might possibly at a push be considered a regs breaker (in a domestic enviroment anyway) is 314-01-01 (i)
Added to that why manufacture cu's with rcd's as mainswitches :confused:

Smoke alarm not being on same RCD as sockets?
Happens all the time on TT supplies. Granted not always on 30mA side but even so the smokes are on an rcd.
 
S

Shakey

  • Thread Starter Thread Starter
  • #10
On a TT system with a split board or if 2x rcd's run in series then yes I agree an S type should be used.



Go on it would help those that dont know. The only one that I can see that might possibly at a push be considered a regs breaker (in a domestic enviroment anyway) is 314-01-01 (i)
Added to that why manufacture cu's with rcd's as mainswitches :confused:





Happens all the time on TT supplies. Granted not always on 30mA side but even so the smokes are on an rcd.

Why wouldnt they manufacture cu's with RCD's as main switches??? We are only talking about using one RCD on a main domestic board to supply all circuits - a sub board supplying a small number of circuits could have a 30mA and comply.

And 314-01-01??? Regulations with zero's in?? you are SOOOOO 2007!!!!

And 'happens all the time'? So does running 4mm cable from the supplementary bonds in the bathroom back to the MET. And bonding radiators and the bloomin sink in the kitchen - but we are trying to discuss what SHOULD happen - not what sparks who dont know the regs pass off as accepteble work!!!!;)
 
E

EasyFox

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  • #11
a sub board supplying a small number of circuits could have a 30mA and comply.
As could any of the wylex such as the NHRS1904 (or any other brand) that uses a 100A 30mA rcd as the incomer. Seen as it has 19 ways why not use it for a domestic installation covering all circuits if you so wished (personaly I wouldnt but there you go).

And 314-01-01??? Regulations with zero's in?? you are SOOOOO 2007!!!!
Ok just for you 314.1 (i) or (iv)
Nothing wrong with 16th not untill July 1st anyway.

bonding the bloomin sink in the kitchen
You mean you dont do this ! JOKING :D

not what sparks who dont know the regs pass off as accepteble work!!!!;)
Yes quite ;)
 
S

Shakey

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  • #12
As could any of the wylex such as the NHRS1904 (or any other brand) that uses a 100A 30mA rcd as the incomer. Seen as it has 19 ways why not use it for a domestic installation covering all circuits if you so wished (personaly I wouldnt but there you go).



Ok just for you 314.1 (i) or (iv)
Nothing wrong with 16th not untill July 1st anyway.



You mean you dont do this ! JOKING :D



Yes quite ;)

nothing wrong with the 16th AFTER 1st of July, as long as the job was designed before 1st of july.:rolleyes:
 
S

Shakey

  • Thread Starter Thread Starter
  • #14
Once the 17th kicks in you will just have a main switch ten RCBO's for every circuit so that are all individually protected.

Why?

For most circumstances a dual split board with two 30mA rCD's protecting 4 or 5 ways each, then an RCBO at the end for your smokes will do

All RCBO's just works out expensive
 
  • Thread Starter Thread Starter
  • #15
Why not just make up a split load board, with an extra rcd, and break up the circuits like we currently do under 16th? s have the main switch, and the smokes circuits, and the RCD, for general things like boiler supply, lighting and cooker, then the next RCD have sockets and some lighting. so that way you will never loose all the lighting but only some and the smokes will always stay active. but on the other hand all smokes have to have battery backup anyway?!so it doesnt atter really on the board configurations.

I can just see that the 17th is gonna cause alot of problems. and personally i feel the 16th edition rules are some of the best, but just needed tweaking, like more RCD's on a 3/4 RCD split board. just seems stupidily over killed. i know protection is in the greatest interest, but the way things are going soon when you sneeze or fart in the wrong room in your house you'll loose power because one of your millions of RCBO's / RCD's has decided to trip.
 
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