rcd as main switch?

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hi, just a quick question can an rcd be used as a main switch? for some reason i think ive heard you cant but not sure now i said it, any help/advice i will be most greatful.

 
it against the regs, they do sell ones that isolate 100a

 
regulations in the 17th edtion under reg, 314.1

 
Not a good idea because if it trips household will be in darkness at night. Plenty of properties are but under 17th you cannot unless you are NICEIC approved.

Batty

 
you can if your niceic approved but it against the regs??

 
i just went to look a house for extra sockets and the main switch was an rcd thats what got me thinking. wat would you advise the customer, is it actually wrong or just bad practice coz if one circuit has a fault it will cause power loss to all circuits

 
i have seen them and i asked the same thing on here, was told to note it as a deviation

 
think tt have a timed delay rcd, split bords still have an main isolator

 
There are thousands even hundreds of thousand properties with voltage operated and current operated circuit breakers as main switches. As you know its not good practice but that was how it was done if electrical supplier did not give earth connection. You can only advise customer how it should be but at the end of the day its night sorry I mean they will only change things if they want to and pay you for doing it. Just remember what you are doing now in another ten yeards or less will not be to current regulations.

Batty

 
glad thats cleared up, will put them down in comments not deviation.

every days a school day.

sorry apache not experienced with tt, 2 100ma

should there be a 30ma some were

 
glad thats cleared up, will put them down in comments not deviation.every days a school day.

sorry apache not experienced with tt, 2 100ma

should there be a 30ma some were
Ideally yes! But would mess the board up. Sockets on main switch RCD.

Suppose compromise would be to leave the two 100mA and get me sockets swapped to RCBO's.

BUT I have 3 radials in a small house!`

 
TT used to be (16th ed)

100mA TD for protection of livestock and against fire

and

30mA for supplementary protection

Now (17th ed) you need 30mA for every socket outlet and buried cables (exceptions apply) so you tend to use twin 30mA RCD CU for everything domestic

 
That would be unlikely.

16th ed CU's (split load) had a main switch that isolated some circuits and also fed an RCD which protected some more circuits.

16th TT CU's had a 100a / 100mA time delay RCD instead of a main switch

17th ed CU's (twin RCD) have a main switch which feed 2 seperate RCD's which protect some circuits each

 
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