how many cables can you fit in to a circuit breaker

[marty1234]

anyone know the reg on how mainy cable can go into a circut breaker .
i know on a ring there will be 2 , shower ther will be 1,cooker 1, what about lighting circuits . I was doing some work in a shop and some other spark is fitting new emg lights he is wiring them out off the lighting 6 amp circuit that has 2 1.5 cables in it at present so he is making it 3 .I would wire from the light switch and fit a test key so i did not have 3 cables in the one breaker
some help on this thanks

 

[Spudnik]

As long as its not ALL the lighting on one breaker then i can see no prob.

Common sense would tell you to make sure they are all secure.

Personally i would probably limit to 3 or 4 at a push.

 

[mrloy99]

anyone know the reg on how mainy cable can go into a circut breaker .
i know on a ring there will be 2 , shower ther will be 1,coocker 1, what about lighting circuits . I was doing some work in a shop and some other spark is fitting new emg lights he is wiring them out off the lighting 6 amp circuit that has 2 1.5 cables in it at present so he is making it 3 .I would wire from the light switch and fit a test key so i did not have 3 cables in the one breaker
some help on this thanks

I would do the same as you.I don't know if there is a particular reg prohibiting it,but to me,a lighting circuit should only have ONE cable at the circuit breaker.If there are more,then surely they should be on a separate circuit with their own CB. I believe that this way you can properly test a circuit,and record results.How do you record results if you have numerous
circuits coming from one CB?

 

[marty1234]

thanks mrloy99 you think the same way as me mate . I think 1 cable to each CB for testing the job i would likr to find some sort off reg for this but dont see one . The sparks that are doneing the job seem to think thay are right putting 3 and 4 cables in 1 breaker for there emg lights .Also they are doing fire alarms in the same job so i had i look 5 cables out 1 10 amp breaker 1 for there new fire alarm,2 intruder alarm ,3 central heating,4 roller shutter,5 socket in back shop
I think these guy have to have a think in what they are doing . STILL TO SEE TEST SHEET ON ALL THE 31 JOBS I HAVE LOOKED AT

 

[maddfridge]

anyone know the reg on how mainy cable can go into a circut breaker .
i know on a ring there will be 2 , shower ther will be 1,coocker 1, what about lighting circuits . I was doing some work in a shop and some other spark is fitting new emg lights he is wiring them out off the lighting 6 amp circuit that has 2 1.5 cables in it at present so he is making it 3 .I would wire from the light switch and fit a test key so i did not have 3 cables in the one breaker
some help on this thanks

hi there

section314

regulation 314.2 is what you are looking for as separate circuits and control, isolation etc

1 breaker 1 circuit as far as i can see end of problem above states that to me

cheers

 

[mrloy99]

thanks mrloy99 you think the same way as me mate . I think 1 cable to each CB for testing the job i would likr to find some sort off reg for this but dont see one . The sparks that are doneing the job seem to think thay are right putting 3 and 4 cables in 1 breaker for there emg lights .Also they are doing fire alarms in the same job so i had i look 5 cables out 1 10 amp breaker 1 for there new fire alarm,2 intruder alarm ,3 central heating,4 roller shutter,5 socket in back shop
I think these guy have to have a think in what they are doing . STILL TO SEE TEST SHEET ON ALL THE 31 JOBS I HAVE LOOKED AT

that is just crazy s*it.Must be contravening a load of regs there.I know fire alarms HAVE to be on their own.I would imagine,the intruder alarm stuff should be on their own too.Totally separate circuits they all should be on individual mcbs.The 10amp mcb on the sockets is a mite unusual too.Even trying to locate a fault on such a multicircuit must be a nightmare.Have they got rcds on sockets and stuff buried in walls at less than 50mm?

 

[Des 56]

Why do you think that more than 1 cable in a breaker is poor practise
If the lighting circuit was both sides of a dist board routing wise then it is safer to feed both sides from the dist board reducing the zs compared with long runs
This is one practical example
There is nothing whatsoever wrong with multiple feeds at one breaker
Circuit design does not have to be as demonstrated in the guides
Safety is the criteria not unusual layouts

 

[ninjadeathstalk]

anyone know the reg on how mainy cable can go into a circut breaker .
i know on a ring there will be 2 , shower ther will be 1,coocker 1, what about lighting circuits . I was doing some work in a shop and some other spark is fitting new emg lights he is wiring them out off the lighting 6 amp circuit that has 2 1.5 cables in it at present so he is making it 3 .I would wire from the light switch and fit a test key so i did not have 3 cables in the one breaker
some help on this thanks

I agree with you on the cooker and shower circuits only one per circuit, but don't forget that a ring main can have more than 2, if a spur is taken off from the consumer unit there would be 3 cables to the mcb.

With the emergency lighting this would need to be taken from the same supply as the lighting for that area, or else it would not illuminate when the supply goes down.

I wouldn't take the supply from the switch. I would take the supply from the nearest light fitting because otherwise you wouldn't have a neutral for the emergency lights.

The total circuit current would need to be calculated and if necessary a new circuit would need to be installed. Because the emergency lighting wouldn't draw very much power, it may well be possible to put them all on the same supply.

 

[matt20687]

the new regs state that only one wire is aloud in each mcb. Although it is stupid that as long as you join the cable outside of the CU then it is fine to have multiple circuits!

 

[DPG]

Where in new regs does it say only 1 cable in each MCB? Are you saying we now can't have a spur fed from the ring circuit mcb?

 

[slrichardson]

Came across this on a pir. Had 2 lighting circuits on one 6a mcb. Checked with niceic for their views and was told its a code 4 'does not comply with bs7671'

 

[Spudnik]

Came across this on a pir. Had 2 lighting circuits on one 6a mcb. Checked with niceic for their views and was told its a code 4 'does not comply with bs7671'

Exactly

 

[mrloy99]

Why do you think that more than 1 cable in a breaker is poor practise
If the lighting circuit was both sides of a dist board routing wise then it is safer to feed both sides from the dist board reducing the zs compared with long runs
This is one practical example
There is nothing whatsoever wrong with multiple feeds at one breaker
Circuit design does not have to be as demonstrated in the guides
Safety is the criteria not unusual layouts

I believe that this is poor practise because of the inability to acurately test and record results.
Whilst I would agree that your zs can be reduced,by this method,it would take lighting circuits to be in excess of hundreds of meters for your disconnection times to become an issue.
Then there is to question of convenience and fitness of purpose,that requires that disconnection after a fault interupts the faulty circuit only.
I would also record a deviation on a pir.

 

[matt20687]

No i dont mean that. I mean that for example in a 6 Amp MCB you can have one 1.0 mm cable for that lighting ciruit and if you have a 32 Amp for a ringmain all you can have is the two ends of the ring in that one mcb.

Understand my madness ?

Sorry if i dont make sense

 

[mrloy99]

No i dont mean that. I mean that for example in a 6 Amp MCB you can have one 1.0 mm cable for that lighting ciruit and if you have a 32 Amp for a ringmain all you can have is the two ends of the ring in that one mcb.

Understand my madness ?

Sorry if i dont make sense

As previous poster said you can have a spur off the ring connected directly into mcb.