Spuring from a spur...

[jb-eye]

Just a note JB:- a double socket outlet will not take 26A, if you look at the back of one it will have 'rated at 13A' this mean the total connected load i.e. both outlets. Many people make that mistake and I only know because i've come across many cheap socket outlets that have started to burn up when connected to say,' dishwasher and washing machine' etc.

53400[/snapback]

Now if i wired a double power point from one point of the ring my maximum conectable load will be 26 amps (2x13a plugs) If i was to install 2 x FCU same load but this does not comply with regs.

IM. Did i not say that a double socket does NOT comply because the load would be 26 amps.

Jef

[An Engineer]

Another way of looking at this. Lets say (for argumemts sake) they allow two spurs from any one point. If there are already two spurs from one point, one in lounge and one in dining room. If someone was to fit an extra spur in the dining room next to existing spur they may not realise that there is already another connected prior to this in the lounge.

Therefore by only allowing one spur it will be obvious when removing the face plate whether it is on a ring or a spur.

Just a thought, thats how I go about it anyway.

[Guest]

I always test it anyway, could be a mid point or end of a radial, a spur, a spur off a spur or a radial from a fused spur on a ring or part of a ring.

[Guest IM_Alarms]

JB- You said the maximum connectable load is 26A, which is wrong, that is like saying that the maximum connectable load of a six way extension lead is 78 Amps. I was just pointing out that this wasn't the correct thing to say.

IM. Did i not say that a double socket does NOT comply because the load would be 26 amps.

Jef

A double socket spurred from the ring does comply with BS7671, would supply two items, but couldn't be used for security equipment as it needs to be an unswitched spur for BS4737 or BSEN50131.

I'm just trying to make sure that we are all giving/ getting the right idea. I think you probably know what is right and wrong, but it doesn't read as you want it too, I think.

[mcelec]

it a matter of applying design principles, spur of the ring cct with a 2.5mm2 t&e cable (carries about 27amps depending on lenght and installation referance method) to two fused connection units both supplying alarm equipment (low load current) completely acceptable!!! any decent electrician with a good understanding of bs 7671 will tell you this!!

and as for saying if you spur of a spur you cant tell if its a spur or on the ring! thats just daft, all you need to do is disconnect supply disconnect point and test for continuity and if you dont get none then either its a spur or its a broken ring, all work should be tested anyway!

most electricians work on the basic rule of you can spur of the ring to;

1 double socket or,

1 single socket then spur from this single socket to another single socket, or,

1 fused spur and then off again to another fused spur

also you can have has many spur's of the ring as there is sockets on the ring and you can spur of for as many fcu's as you want, but remember its all a matter of design!!!!! so if you dont have a good working knowledge of cable calculations and basic electrical design principles then call a proffessional because at the end of the day ELECTRICITY KILLS

[Lectrician]

One spur from the ring per accessory.

No more spurs than there are sockets.

You may spur using a JB in the ring, or from the CU fuse terminals (but still no more spurs than sockets).

You can have either 1 double socket, 1 single socket or 1 FCU at the end of a spur.

Just because you know the load is not going to exceen the 2.5's rating (taking into account install method) doesn't mean you can bung two spurs on.

A FUSED spur can have as many sockets as you like, and can be run in a minimum cable size of 1.5mm (most people still bung 2.5 in). You spur from the ring to an FCU, and then from the output side of this to however many other spurs/sockets you want.

Ideally your alarms should be on their own cct anyway, typically a 20amp radial using 2.5mm cable. (but a 6amp or 10amp MCB feeding the panels FCU via 1.0 or 1.5 cable would still be ok). With new CU's and new builds, the sockets should be protected by an RCD. You don't really want your panel on that.

Hope that clears a few things up.

[Guest]

One spur from the ring per accessory.

No more spurs than there are sockets.

You may spur using a JB in the ring, or from the CU fuse terminals (but still no more spurs than sockets).

You can have either 1 double socket, 1 single socket or 1 FCU at the end of a spur.

Just because you know the load is not going to exceen the 2.5's rating (taking into account install method) doesn't mean you can bung two spurs on.

A FUSED spur can have as many sockets as you like, and can be run in a minimum cable size of 1.5mm (most people still bung 2.5 in).  You spur from the ring to an FCU, and then from the output side of this to however many other spurs/sockets you want.

Ideally your alarms should be on their own cct anyway, typically a 20amp radial using 2.5mm cable.  (but a 6amp or 10amp MCB feeding the panels FCU via 1.0 or 1.5 cable would still be ok).  With new CU's and new builds, the sockets should be protected by an RCD.  You don't really want your panel on that.

Hope that clears a few things up.

53558[/snapback]

I was waiting for your view on this one the point about the alarm being spurred off a socket circuit that is RCD fed < Im sure most have done this at some time or another including me - apart from nuiscence tripping, does it violate code or regs??

[An Engineer]

and as for saying if you spur of a spur you cant tell if its a spur or on the ring! thats just daft, all you need to do is disconnect supply disconnect point and test for continuity and if you dont get none then either its a spur or its a broken ring, all work should be tested anyway!

53514[/snapback]

So if you find a spur with one cable, how do you know that there is nothing else between that and the ring, given that any other spurs could be hidden behind furniture etc.

[Guest IM_Alarms]

If you want to know for certain, it will involve proving what is fed from where on any other accessories in the vacinity. It is possible to test and prove what is on the ring and what is spurred by using a method which most people who have done the 2391 should know and use. Then it should be a case of proving the spurs are not in series. The readings at each should be a good indication for a start.

If you don't have a lot of testing experience and want an easy method to follow, find a spur, find where that is spurred from the ring, disconnect the spurred live and see if anything else goes off with it. Don't forget to switch it off before disconnecting.

[Guest IM_Alarms]

it a matter of applying design principles, spur of the ring cct with a 2.5mm2 t&e cable (carries about 27amps depending on lenght and installation referance method) to two fused connection units both supplying alarm equipment (low load current) completely acceptable!!! any decent electrician with a good understanding of bs 7671 will tell you this!!

and as for saying if you spur of a spur you cant tell if its a spur or on the ring! thats just daft, all you need to do is disconnect supply disconnect point and test for continuity and if you dont get none then either its a spur or its a broken ring, all work should be tested anyway!

most electricians work on the basic rule of you can spur of the ring to;

1 double socket or,

1 single socket then spur from this single socket to another single socket, or,

1 fused spur and then off again to another fused spur

also you can have has many spur's of the ring as there is sockets on the ring and you can spur of for as many fcu's as you want, but remember its all a matter of design!!!!! so if you dont have a good working knowledge of cable calculations and basic electrical design principles then call a proffessional because at the end of the day ELECTRICITY KILLS

Hmmmmm, think you should check you facts a bit before you put so many !!!!!!!!!'s in