2 FCU in Series for Outdoor Socket

[jac]

Hi everyone, hope you're well on this dull Sunday afternoon

I want to add an outdoor socket for the garden and was hoping to use an existing (unused) FCU inside the house... For clarity, when we moved into the house I saw there was an FCU next to a double socket. I was told this was for an outdoor light, which was removed but they left the FCU in place and removed the old wire.

I've had a look, the socket is on the ring main, the FCU spurs from this and nothing is connected to the load side at all. In fact it has been switched off for about 5 years so I don't think anything important is connect to it!

To save mess inside (and keep her fancy face plate), I was hoping to drill out the house from the back of this FCU. I was going to run 1.5mm Hi-Tuff through the wall into an IP66 RCD/FCU unit directly outside. Both FCU have 13A fuses fitted. The Hi-Tuff is rated to 20A (NYY-J PVC HI-TUFF 1.5mm 3 CORE).

From the outdoor RCD/FCU I was then hoping to have a short run along the wall (~4m) with more Hi-Tuff to a IP66 socket.

The benefit for this is that I can isolate from inside, there is RCD protection added and the RCD box means I don't have to worry about bending the Hi-Tuff as it leaves the house.


I guess all this is a long winded way of saying.... can I have a double on the ring main -> switched 13A FCU -> Hi-Tuff -> IP66 13A RCD/FCU (no switch) -> Hi-Tuff -> IP66 garden socket.

The socket is for LED decking lights/water feature or lawnmower?

Thanks for your time!
jac.

 

[Pete999]

Hi everyone, hope you're well on this dull Sunday afternoon

I want to add an outdoor socket for the garden and was hoping to use an existing (unused) FCU inside the house... For clarity, when we moved into the house I saw there was an FCU next to a double socket. I was told this was for an outdoor light, which was removed but they left the FCU in place and removed the old wire.

I've had a look, the socket is on the ring main, the FCU spurs from this and nothing is connected to the load side at all. In fact it has been switched off for about 5 years so I don't think anything important is connect to it!

To save mess inside (and keep her fancy face plate), I was hoping to drill out the house from the back of this FCU. I was going to run 1.5mm Hi-Tuff through the wall into an IP66 RCD/FCU unit directly outside. Both FCU have 13A fuses fitted. The Hi-Tuff is rated to 20A (NYY-J PVC HI-TUFF 1.5mm 3 CORE).

From the outdoor RCD/FCU I was then hoping to have a short run along the wall (~4m) with more Hi-Tuff to a IP66 socket.

The benefit for this is that I can isolate from inside, there is RCD protection added and the RCD box means I don't have to worry about bending the Hi-Tuff as it leaves the house.


I guess all this is a long winded way of saying.... can I have a double on the ring main -> switched 13A FCU -> Hi-Tuff -> IP66 13A RCD/FCU (no switch) -> Hi-Tuff -> IP66 garden socket.

The socket is for LED decking lights/water feature or lawnmower?

Thanks for your time!
jac.

If you have an RCD / FCU with no output there will be no reason why you can't just use that, no need for another FCU.

 

[Ian1981]

If your bothered about 2 fuse Spurs switches change the indoor one to a 20amp double pole switch as a means of isolation

 

[jac]

Thanks for the speedy replies!

If you have an RCD / FCU with no output there will be no reason why you can't just use that, no need for another FCU.

The indoor is just a FCU 13A, it was more a case of using what I have indoors to avoid disturbing anything, then adding the RCD outside for safety.

If your bothered about 2 fuse Spurs switches change the indoor one to a 20amp double pole switch as a means of isolation

So the indoor is 13 Amp Double Pole Switched Fused Spur Connection Unit currently. Why does the indoor need to be 20amp? Does it matter if both are 13A?

 

[Octopus]

Does your fuseboard not have rcd's?

 

[Ian1981]

Thanks for the speedy replies!



The indoor is just a FCU 13A, it was more a case of using what I have indoors to avoid disturbing anything, then adding the RCD outside for safety.



So the indoor is 13 Amp Double Pole Switched Fused Spur Connection Unit currently. Why does the indoor need to be 20amp? Does it matter if both are 13A?

Not really but if your bothered about having 2 13amp fuses in series then just change the indoor one to an isolation switch for outside socket as I think you said outside rcd socket doesn't have a isolation switch on it not that it's a problem just an option

 

[jac]

Does your fuseboard not have rcd's?

No, just MCB for that circuit. I thought RCD would be required for a spur?

Not really but if your bothered about having 2 13amp fuses in series then just change the indoor one to an isolation switch for outside socket as I think you said outside rcd socket doesn't have a isolation switch on it not that it's a problem just an option

Thanks again, did you suggest 20A as that is the rating of the wire? Not questioning you suggestion I just like to know the reasoning.

 

[Ian1981]

No, just MCB for that circuit. I thought RCD would be required for a spur?



Thanks again, did you suggest 20A as that is the rating of the wire? Not questioning you suggestion I just like to know the reasoning.

No just that if it's not a fused spur then most double pole switches are rated at 20 amps.
The fused spur externally will offer the overload for the external power limited to 13amps

 

[jac]

No just that if it's not a fused spur then most double pole switches are rated at 20 amps.
The fused spur externally will offer the overload for the external power limited to 13amps

Thanks again for the confirmation.

I was just concerned about running the RCD/FCU from a FCU... but in my case there is only one load, so it in effect is just an isolator.

What a helpful site!

 

[telectrix]

why not just come from the FCU in the house in T/E to a IP 55 ad. box, then join with wagos to hi-tuff to a RCD socket?

and i'm surprised that you have ring final/s for sockets without RCD protection anyway.