ring lighting circuit??

[richamallo]

i have just replaced the 1st floor of our cottage and in the process of rethreasding all of the existing cables through the new joists. i notied that all the lights appear to be on one ring circuit.....

1. why would anyone have wired a ring circuit for lighting on a b6 mcb with 1.5te?, i understand there may be a voltage drop issue (cottage is 10mx6m, 2 storey) but if that was the case i would have thought that the logical thing to do would be to put 2 circuits in rather than one ring.

2. is it possible that 2 circuits are employed but some diy hero has put them both through one mcb?

3. does it sound like a cause for concern or normal practice?

 

[EFLImpudence]

1. why would anyone have wired a ring circuit for lighting on a b6 mcb with 1.5te?,

Ignorance ?

i understand there may be a voltage drop issue (cottage is 10mx6m, 2 storey) but if that was the case i would have thought that the logical thing to do would be to put 2 circuits in rather than one ring.

1mm² would be ok for 90metres of cable as far as voltage-drop so??? 1.5mm², 50%more.
Two circuits would be better anyway.

2. is it possible that 2 circuits are employed but some diy hero has put them both through one mcb?

Anything is possible but then it would not be a ring.

3. does it sound like a cause for concern or normal practice?

Not really. You can put it right now

 

[riveralt]

i have just replaced the 1st floor of our cottage and in the process of rethreasding all of the existing cables through the new joists. i notied that all the lights appear to be on one ring circuit.....

1. why would anyone have wired a ring circuit for lighting on a b6 mcb with 1.5te?, i understand there may be a voltage drop issue (cottage is 10mx6m, 2 storey) but if that was the case i would have thought that the logical thing to do would be to put 2 circuits in rather than one ring.

I take it you have two line cables in the one mcb.
Are you basing your 'ring' view on visual observation or have you conducted end to end continuity tests and what are those results.

2. is it possible that 2 circuits are employed but some diy hero has put them both through one mcb?

How many mcbs are in the cu - are there spare ones?

3. does it sound like a cause for concern or normal practice?

Concern Yes - if true what else is wrong. Normal Practice No.

 

[EFLImpudence]

1. why would anyone have wired a ring circuit for lighting on a b6 mcb with 1.5te?,

I assumed the query in your question was the 'ring' part.

After rereading, I am now wondering if it is the 'B6 mcb' or '1.5mm²' about which you are unsure.

 

[richamallo]

i have just replaced the 1st floor of our cottage and in the process of rethreasding all of the existing cables through the new joists. i notied that all the lights appear to be on one ring circuit.....

1. why would anyone have wired a ring circuit for lighting on a b6 mcb with 1.5te?, i understand there may be a voltage drop issue (cottage is 10mx6m, 2 storey) but if that was the case i would have thought that the logical thing to do would be to put 2 circuits in rather than one ring.

I take it you have two line cables in the one mcb.
Are you basing your 'ring' view on visual observation or have you conducted end to end continuity tests and what are those results.

2. is it possible that 2 circuits are employed but some diy hero has put them both through one mcb?

How many mcbs are in the cu - are there spare ones?

3. does it sound like a cause for concern or normal practice?

Concern Yes - if true what else is wrong. Normal Practice No.

thanks for the speedy replies. yes, my "ring" view is based on assumption of there being 2 wires into the mcb....hence why i was asking if there was any other obvious explanation that someone with a few more a-levels than me may be able mcb on the cu with to offer. i will do the continuity test to establish the ring theory. there are eight mcbs on the cu with three spare ones. how bigga job would it be to split it into 2 circuits ( assuming it is all on one ring circuit) and any approx costs if poss to offer?.....i know this will be the old piece of string answer but would we be talking early hundreds, late hundreds or worse??

 

[richamallo]

1. why would anyone have wired a ring circuit for lighting on a b6 mcb with 1.5te?,

I assumed the query in your question was the 'ring' part.

After rereading, I am now wondering if it is the 'B6 mcb' or '1.5mm²' about which you are unsure.

the ring part was my main query....i would have expected to find 1mm or 1.5mm on a b6 on two circuits, maybe one upstairs and one downstairs. what i found just seemed alien and i with my limited knowledge i couldnt understand what would be gained by a ring on a b6......the only explanation i could thinl of was volt drop but as you said, surely that would give even more reason to have it over tewo circuits. whilst i have the house this far stripped the work may as well be done if it needs doing is my thinking but i just like to understand what needs doing before i pay for it!!

 

[riveralt]

thanks for the speedy replies. yes, my "ring" view is based on assumption of there being 2 wires into the mcb....hence why i was asking if there was any other obvious explanation that someone with a few more a-levels than me may be able mcb on the cu with to offer. i will do the continuity test to establish the ring theory. there are eight mcbs on the cu with three spare ones. how bigga job would it be to split it into 2 circuits ( assuming it is all on one ring circuit) and any approx costs if poss to offer?.....i know this will be the old piece of string answer but would we be talking early hundreds, late hundreds or worse??

It sounds as if you have two radial lighting circuits coming out of one mcb which itself is not a problem depending on the load, but if you have spare capacity at the cu and one of the spare mcbs is 6Amp then splitting the circuits would be an advantage.
Cost wise, if the circuit that is moved tests out okay and you have a spare 6Amp mcb then no more than one hour max - £50/75.
However, as you appear to have moved - disconnected/reconnected many cables when replacing the joists it might be worthwhile getting an Electrical Installation Condition Report completed so you are sure that all the circuits test results meet current standards. Price between £100/200 though it does depend on the area you live in.

 

[17thman]

As riveralt says, circuits must test ok before connecting one set of conductors to a spare 6A mcb, if the lighting circuit was genuinely wired as a ring and you do not check end to end continuity for open circuit, you may end up energising one circuit from 2 mcbs's.

 

[1john]

The two circuits may be on one MCB as they may share a neutral and perhaps this is how someone overcame the problem when doing a consumer unit change at some stage, more info required.

 

[17thman]

 

[Taylortwocities]

Do your end to end continuity tests to determineif it is a "ring" or not.

I'll bet its not a ring and that the second cable is something like the garage lights, or the doorbell.
Quite honestly, there's no point changing it unless you are worried about losing all your lights at once, or if the existing B6 is tripping due to current overloading.

 

[ban-all-sheds]

the ring part was my main query

No - it was an utter guess based on truly flaky understanding.

...i would have expected to find 1mm or 1.5mm on a b6 on two circuits, maybe one upstairs and one downstairs. what i found just seemed alien and i with my limited knowledge i couldnt understand what would be gained by a ring on a b6

You have absolutely no evidence that it is a ring, and not two circuits - why on earth have you decided that it's a ring?

 

[richamallo]

the ring part was my main query

No - it was an utter guess based on truly flaky understanding.
it was one of two theories based on limited knoweledge and understanding....hence why i was asking the helpful experts on here in order to gain a better understanding and knowledge of how to understand what could be wrong or what remedial measures may need to be taken.....and everyone has been very helpfull until you came along with demeaning and sarcastic remarks. if you dont want to offer help and advice, please do not message me. thank you

...i would have expected to find 1mm or 1.5mm on a b6 on two circuits, maybe one upstairs and one downstairs. what i found just seemed alien and i with my limited knowledge i couldnt understand what would be gained by a ring on a b6

You have absolutely no evidence that it is a ring, and not two circuits - why on earth have you decided that it's a ring?

 

[richamallo]

Do your end to end continuity tests to determineif it is a "ring" or not.

I'll bet its not a ring and that the second cable is something like the garage lights, or the doorbell.
Quite honestly, there's no point changing it unless you are worried about losing all your lights at once, or if the existing B6 is tripping due to current overloading.

thanks. i will test the continuity. it doesnt trip so it isnt a niusance or any inconvenience, it was just that i have not seen a lighting circuit that lokked like this before.