Spur from a spur

[robhayes]

Hi,

I would like to spur off an existing socket to supply a new (single) socket, however when investigating I've found that my existing socket is already a spur from the ring main.

After reading various sources it seems that spurring from a spur is a no-no..... (what is the reasoning behind this? because of the current going through two sets of single wires?)

however I was wondering if this is possible if I install a 13A FCU before the first spur so that only a 13A load can be supported

any comments greatfully recevied

 

[FredFlintstone]

As far as I know, what you propose (to fit a 13a FCU between ring main and first spur) is acceptable.

Not ideal but acceptable.

Like I say, this is as far as I know to be true - I'm not a pro spark so please wait for proper advice before proceeding.

The reason I replied though is to ask:

Would it not be possible to join the existing spur into the ring main thus meaning you can take your additional socket from this?

Fred.

 

[robhayes]

Hi,

Firstly thanks for the response and I don't worry I'll wait for a bit more advice before proceeding.

I haven't fully investigated yet as to wether I can make my existing spur part of the ring.. but I believe I may have issues as I have a relatively old house and difficulty running cables.

If I were to investigate this though presumably I would need to find the socket that feeds the spur and then take one of it's ring main wires and connect this to to my existing spur instead... thus binging my spur in to the ring?

BTW: So the reason you wouldn't normally spur from a spur is that you are potentially going to be loading the wires with too much current if someone plugs in a number of current hungry devices in to what looks like two seperate sockets but what actually is a spur?

BTW2: just out of interest...presumably spurring from a spur is theoretically the same as plugging in 4-way ganger plug to the spur socket?

Thanks,

Rob

 

[RobFurn]

BTW2: just out of interest...presumably spurring from a spur is theoretically the same as plugging in 4-way ganger plug to the spur socket?

not exactly remember the 4 gang is protected by the fuse in the 3 pin plug

Re fused spur its fine so long as the rating of the fuse in the FCU is not greater than the rating of the cable and should not exceed 13A in anycase. Remember the FCU is to protect the cable. The number of socket outlets supplied by the fused spur is unlimited but will only carry a max of 13A so check your demand i.e. dont have a wasing machine tumble dryer ect connected they will blow the fuse soon enough if switched on together.

 

[dw3101]

A spur from a spur is allowed AFAIK as long as it doesnt exceed a set number, maybe old regs Im thinking off though..

As far as Im concerned a spur off a spur or a ring is a source of evil as when people are adding stuff they dont tend to split the ring and check, they just assume its a ring as there are two cables

 

[RobFurn]

A spur from a spur is allowed AFAIK as long as it doesnt exceed a set number, maybe old regs Im thinking off though..

No its not 1 unfused spur per socket outlet from the ring is all thats allowed unless the spur is a fused spur then you can be sure the whole spur is protected by the 13 amp fuse.

basically an unfused spur is a radial circuit overload it and the (ring) 32A MCB will not protect the cable. Overloading one socket of an unfused spur wont happen as 13A is the max fuse rating you can put in a 3 pin plug. Adding more sockets increaes the risk of increasing the load and bang goes your cable before the MCB trips.

Remember its the cable your protecting

 

[robhayes]

Cool... thanks everyone for the input it's most welcome..

I think basically what we are saying is that I can either;

1) Try and make my existing spur part of the ring and then spur from that (best to do)

2) Add a 13A FCU before my existing spur and then spur from my spur but then in the future someone run's the risk of opening up my existing (first) spur and thinking "Oh it's got two cables so it must be part of the ring main"

Still alot of learning for me to do clearly!