Spur from a spur - options

[JohnW2]

There's also the question, particularly in a kitchen, of 'when is a spur a spur'.

If each of the under-counter appliances is plugged into an under-counter socket which is fed as a spur from a ring final circuit, then that is called 'multiple spurs', and deprecated by some.

However, it seems quite fashionable to have above-counter switches/isolators for each appliance (discrete ones, or a bank of grid switches) each feeding an under-counter socket (or sometimes even FCU) for the appliance concerned. This seems to be regarded as being at least 'acceptable', and at least some seem to regard it as a 'good practice'. However, is it logical that inserting a switch in the cable changes it from being a 'deprecated spur' to an acceptable, perhaps even 'good', practice?

Kind Regards, John

 

[lxboy]

Hi, sorry are you asking a question ?


Lxboy

 

[JohnW2]

Hi, sorry are you asking a question ?

No need to be sorry but .... Indeed - the clue is in the question mark at the end of the final sentence. However, some may prefer to regard it as a rhetorical question and simply comment (or ignore).

Kind Regards, John

 

[lxboy]

Sorry Again !

As you appear to know all the answers, it's a bit of a shock

As always,

kind regards,

Lxboy

 

[scousespark]

asterix - do you know if you have a ring or radial circuit?

 

[asterix187]

Unfortunatey not. Is there an easy way to tell? The house was built around 1970...

 

[JohnW2]

Unfortunatey not. Is there an easy way to tell? The house was built around 1970...

If that's the vintage of the wiring, then I would think that it's very likely a ring circuit. It would take lots of tests to be absolutely certain that it was a ring, but one could get a pretty good idea if one had seen inside the consumer unit.

In any event, I think a probably more important question is the rating of the MCB ('breaker') or fuse in your CU/fuse box which controls the kitchen circuit in question. If that is 30A or 32A (and assuming that is appropriate for the circuit!), and if the cable of your existing spur is 'standard' 2.5mm² cable, then I think that everything which has been said still apllies, whether it is a radial or a ring circuit.

Kind Regards, John

 

[scousespark]

Unfortunatey not. Is there an easy way to tell? The house was built around 1970...

If that's the vintage of the wiring, then I would think that it's very likely a ring circuit. It would take lots of tests to be absolutely certain that it was a ring, but one could get a pretty good idea if one had seen inside the consumer unit.

In any event, I think a probably more important question is the rating of the MCB ('breaker') or fuse in your CU/fuse box which controls the kitchen circuit in question. If that is 30A or 32A (and assuming that is appropriate for the circuit!), and if the cable of your existing spur is 'standard' 2.5mm² cable, then I think that everything which has been said still apllies, whether it is a radial or a ring circuit.

Kind Regards, John

So, based on the age of the property, you know it's a ring. Were radials invented in 1980? In any case, do you know if it has been rewired?

Do you advise astrix to put in an FCU, even if it is a radial and an FCU is not needed?

As for the important question. Surely you might want to ask about the presence of an RCD and the installation method.

 

[JohnW2]

Welcome back! It's some time since you last appeared to take me to task - I've missed you

So, based on the age of the property, you know it's a ring.

Read what I wrote. As far as I am concerned, "I know" and "I think it is very likely" have somewhat different meanings.

Were radials invented in 1980? In any case, do you know if it has been rewired?

As I need not tell you, 'Yes' and 'No' respectively - although, as for the latter, the fact that the OP told us the build date in response to being asked whether it was a ring or a radial rather suggests that he believes the wiring is original (although I accept that his belief maybe incorrect). In any event, again, read what I wrote, namely "If that's the vintage of the wiring, then I would think that it's very likely a ring circuit".

Do you advise astrix to put in an FCU, even if it is a radial and an FCU is not needed?

Again, read what I wrote: "If that is 30A or 32A (and assuming that is appropriate for the circuit!), and if the cable of your existing spur is 'standard' 2.5mm² cable, then ....". If those two 'ifs' were true, then I don't understand why you think an FCU would not be needed. Whether it is a 30A/32A-protected ring or a 30A/32A-protected radial (wired in 4mm² cable, 'as appropriate for the circuit'), if the existing spur is 2.5mm² and the OP wants to use that to supply two double sockets, he surely does need an FCU? AFAICS, only if it were a 16A/20A radial (such that my first 'if' would not be true) or if it were a 30/32A radial with all cable (including that to the present 'spur') being in 4mm² (such that my second 'if' would not be true) would there be no need for an FCU. Do you disagree (with what I actually wrote)?

As for the important question. Surely you might want to ask about the presence of an RCD and the installation method.

I agree that no-one has yet asked about RCD protection, and that's an important question which should have been asked. The same for installation method, I suppose, but I doubt that will be an issue for sockets in a kitchen. As I presume you actually understand, what I actually meant was that the rating of the OPD and the CSA of the existing sour cable were more important questions than the question of whether the circuit was a ring or radial.

Kind Regards, John

 

[asterix187]

Quick question. I have fitted the fused spur and the first socket which all works great. Do I attach the second socket to the first socket or to the fused spur?

 

[riveralt]

Quick question. I have fitted the fused spur and the first socket which all works great. Do I attach the second socket to the first socket or to the fused spur?

Normally you would attach the second socket to the first.
But since the circuit after the fuse has become a radial I don't see there being an issue with connecting the second socket to the load side of the FCU should you wish to. Some may disagree.

 

[JohnW2]

Quick question. I have fitted the fused spur and the first socket which all works great. Do I attach the second socket to the first socket or to the fused spur?

Normally you would attach the second socket to the first.
But since the circuit after the fuse has become a radial I don't see there being an issue with connecting the second socket to the load side of the FCU should you wish to. Some may disagree.

I agree with all that, and I don't see why anyone should disagree with the last bit, provided that the load terminals have enough physical capacity (and, theoretically, 'rated physical capacity') to take two sets of conductors (which I imagine they probably would).

Kind Regards, John

 

[asterix187]

Thats great! For some reason I just assumed this is how it would be done so I chased out the wall to both sockets from the FCU. Not really an issue if I couldn't do it that way but means i didn't damage the wall for nothing. The second socket probably wont ever get used anyway

 

[scousespark]

I'm sorry John, I don't think it's sensible working on assumptions.
In ypur frst answer you said it was probably a ring. There was nothing in the thread to confirm or disprove this . I didn't say an FCU was not needed on a ring, just that it isn't needed on a radial.

The age of the house is irrelevant. The house wiring may have been updated many times since 1970. Unless you are on-site, you can't know what is installed.

Asterix posted the following on Monday afternoon.

The spurs were already there and done by whomever did the work before I moved in.

 

[NickB_99]

The spurs were already there and done by whomever did the work before I moved in.

Hi Asterix.
I was in a similar position to you when I had my kitchen recently done.
I moved in May 2012 and had the kitchen done in April 2013.
The house wiring was functioning ok but showing signs quite a lot of work at different times previously (T&E old colours, new colours, some white insulation etc) and the CU was a little old with not many RCDs etc.
So I bit the bullet and got a new circuit put in for the kitchen and the rest was left on the original ring. Updated the CU at the same time and it didn't cost the earth for all the work.
I'm glad I did. Now have a new kitchen with a decent supply round it and less load on the original ring.