Problem adding sockets

[ColJack]

the power shower pump no longer works but you haven't had your weekly shower yet ?

the outside light no longer works but you're in bed before it's dark to notice?

 

[Hagarbloke]

Washing is for hygienic wimps, and I can see in the dark with my night vision eyeballs.

 

[PrenticeBoyofDerry]

The CU in the kitchen IS an old one without RCD protection. One of the sockets I'm adding to the workshop will have a built in RCD and I'll use this outlet for working on/testing live equipment (i'm an electronics engineer). The other two sockets will power bench test equipment like my scope, meters and variable power supply. When budget allows I plan to get the CU replaced for a modern one with RCD protection. I've recently replaced the shower but not using it yet until the new CU is in place.

If your having a socket with intergrated RCD protection, you may as well put in a FCU with RCD protections then the whole lots covered!
and no RCD protection the shower

 

[Hagarbloke]

I don't want all the sockets RCD protected as some of the equipment I work on will have high earth leakage currents and will cause nuisance tripping, like HT PSU's for gas lasers which often have capacitive coupling to earth.

The original shower was years old and probably fitted when there was no requirement for bathroom circuits to be RCD protected. I've ripped that one out and fitted a modern shower but we only use the bath at the moment. Mentioned to the wife about the regs requiring an RCD for bathroom electrics and she's scared to even look at it now without fearing getting blown up.

 

[PrenticeBoyofDerry]

Someone please correct me if I'm wrong the regulations state that all socket-outlets rated up to 20Amps should be protected by 30mA RCD.
The exemptions being:
1) supervised by skilled/instructed persons (commercial/industrial enviroment)
and
2)specially labeled socket outlet for supplying a particular piece of equipment (this would be separate circuit)

So if I was installing new/additional sockets I would install an RCD at that/them points.
So if I was adding a spur on to an existing ring final circuit they would be run off a RCD FCU or the socket would have an intergrated RCD.
If I was extending a ring final circuit (adding sockets to it) each socket should be an RCD protected socket(intergrated) or an RCBO should be installed as the protective device for the whole circuit, assuming no RCD protection on the main board.
Is that right, mostly right, partly right or a load of hog wash?

 

[ahll]

Hi all
I have been looking at the sockets in the house and I think there is a Spur feeding another socket. Can someone explain why this is a problem ?

Thanks

 

[PrenticeBoyofDerry]

Hi all
I have been looking at the sockets in the house and I think there is a Spur feeding another socket. Can someone explain why this is a problem ?

Thanks

If it's a single spur from a socket that is directly on the circuit (ring final/radial circuit)
not problem but if it's a spur from another spur it's a no no

 

[ahll]

Thanks I understand that a spur on a spur is a no no but I dont understand why its a no no..can anyone explain ?

 

[ColJack]

1 socket = 13A
2 sockets = 26A
3 sockets = 39A
4 sockets = 52A..... etc.. etc..

the 2.5 you use for the spur would only take 27A max..

also you would be loading one point on the ring more than the rest..

 

[ahll]

ok so you use a 13amp FCU because its keeps it at 13amps even if there are 1 2 3 etc sockets on it..instead of the 13 26 39 etc is that right ?

 

[ColJack]

yes, it limits it to 13A..

you can have a double socket on a spur, because the 2 x 13A fuses limit it to 26A.. ( can't have 2 single sockets spured one of another though for some reason.. )