swa

[still learning.]

Hi, I'm putting thre double sockets near my fish pond using swa, can I link the neutrals in the sockets and have one returning neutral or do they need one each. I am putting a seperate cu with rcd for the sockets coming off the non rcd side of my existing cu for the house and having each socket on its own 6A cb .

cheers

 

[i=p/u]

i would say you only need one radial circuit for all 3 sockets

 

[johnboy6083]

why are you sitinmg sockets near a fish pond? are they to power a pond pump/filter ect. Are the sockets IP rated for the conditions. How are you going to test the circuit to ensure disconnection times are met and that you do not suffer from excessive voltage drop? also are you aware that work of this nature comes under part P of the building regulations?

 

[Knobhead]

You need to give more details.

We can only guess what your intensions are at the moment.

 

[still learning.]

sorry I missed out it's my mates pond. I have a metrel 3002 eurotester and all testing will be done.

the sockets are for pumps and uv's for his pond and he wants to have the three double sockets on their own circuit and a seperate rcd so if there is a problem the rcd for the house will not trip and mcb will not stop all the pumps working just the one with the fault but thinking about it I can do away with the rcd and use rcbo's that way if the rcd was to trip it will not trip them all just the faulty circuit.

I was just wondering if I needed a seperate neutral for all three sockets or could I link the socket neutrals and have one retutning neutral?

 

[telectrix]

i would supply all 3 from a 16A or 20A MCB. and RCD. each plug top would most likely be fused at 5A, so you would have your discrimination there

 

[still learning.]

I am going to use a 32a mcb off the non rcd side of the main cu to feed the new cu will there be enough discrimination between the 16 and 32a so the 16a trips first

 

[kamkam]

How about... 20amp radial in swa from non rcd side of ccu in property feeding 3 IP65 rcd spurs for pond stuff

or 20amp rcbo from inside property feeding 3 IP65 spurs for pond stuff

All above taking voltdrop and Ib<In<Iz into account

 

[Richard Burns]

16A will discriminate from 32a in most cases.
If you are going to run 3 separate circuits then each one will need a separate neutral not a combined neutral.
Much better (and cheaper) to have one circuit and then there is no need for multiple cables to the pond or another CU. but would need to be an RCBO in the main CU on the non RCD protected side.

 

[still learning.]

thats what he has now but but he wants them all on seperate circuits. thanks for just clarifying the neutral for me and for all your help.
cheers

 

[Richard Burns]

If he wants to avoid nuisance tripping on RCDs then you could just change the sockets for RCD sockets. The local plug fuses will provide discrimination on fault current and overload and the individual RCDs would trip separately for each socket. The Swa does not need RCD protection as it has an earthed sheath.