Bunched cables lighting circuit

[11kstanton]

Hi all

I carried out a pir today (eicr) and there were 3 lighting circuits all bunched with 3 cables in each of them so totalling 9 cables over 3 mcbs seems extreme. Does each lighting circuit need to be on its own separate mcb, and wondering what code this would be if any? There is no spare ways in DB and is already a 14way,

your thoughts appreciated

 

[matt.smallbone]

Hi, I had this problem and spoke to the powers that be at my firm, according to them it depends on the load of the combined cables, but only two together is acceptable, they said that its probably a C3 as improvement is recommended but if there is any sign of overheating or a big load being drawn through the cable then it's a C2 as there is a sign of danger present. Hope this helps!!

 

[11kstanton]

Thanks, so looks like they will have to get a new DB installed as there isn't any space to move 2 out of the 9 cables to allow it to be max 2 cables per MCB. If it is max 2 cables for these lighting circuits ill probably stick it on the cert as a c 2 as they are going to have to do something to get it sorted

 

[Des 56]

Is the rating of the mcb correct with regard the smallest sized conductor ?

If this connection at the mcb was situated in an accessible junctoin box,would you have concern ?

Please state the regulation number that gives a maximum of 2 cables per mcb ? ( I suppose a ring final with a spur off the mains has no doubt been installed incorrectly)

 

[Octopus]

What's the load on each MCB?

 

[Guest55]

C2 ??
good grief.

 

[matt.smallbone]

That's true actually, if it was an accessible joint I wouldn't have the same concern! And as far as I was aware it was a guideline set by the NICEIC that anything over two cable on a lighting MCB is deemed to be poor practise and if possible the circuits should be split on to separate MCB's.
And with regards to the spur from a ring in a consumer unit, that is a predicted method of connection again where possible as the joint or connection can be seen at the consumer unit and your not hinting for the connection, not always practical I know!!

 

[Octopus]

That's true actually, if it was an accessible joint I wouldn't have the same concern! And as far as I was aware it was a guideline set by the NICEIC that anything over two cable on a lighting MCB is deemed to be poor practise and if possible the circuits should be split on to separate MCB's.
And with regards to the spur from a ring in a consumer unit, that is a predicted method of connection again where possible as the joint or connection can be seen at the consumer unit and your not hinting for the connection, not always practical I know!!

Since when did they write the rules?

 

[Silly Sausage]

Thanks, so looks like they will have to get a new DB installed as there isn't any space to move 2 out of the 9 cables to allow it to be max 2 cables per MCB. If it is max 2 cables for these lighting circuits ill probably stick it on the cert as a c 2 as they are going to have to do something to get it sorted

I hope the person ordering the Report gets a second opinion.
Can't see them being very happy about having to shell out for a (totally unnecessary) 16 way DB change!!!

 

[matt.smallbone]

They don't write the rules at all, but if that's advice they are giving, then they ultimately allow my employer to certificate work. So they have a pretty big input……

 

[monkeyelectric]

I can't see a problem as long as the ocpd is rated for the ccc of the smallest cable and volt drop

 

[Des 56]

matt,the Niceic can drown in a sea of its own rules for all I care about those criminals

However this is a forum that encompasses all the IET has to suggest on electrical installation

Confusion can be caused by people getting advise for installation practices mixed up with the garbled opinions issued by the Niceic for rules for its own members,instead of IEE actual regulation which should be the guide

The Niceic sometimes speak with forked tongue

 

[D Skelton]

C2 ??
good grief.

I'd have gone C1 definitely! Get the fire brigade in NOW!!!

 

[D Skelton]

I carried out a pir today

Does each lighting circuit need to be on its own separate mcb

I mean no disrespect but judging by these questions you are not competent enough to be carrying out EICRs

 

[Guest55]

the lateral thinkers among us would pull all those cables into the ceiling void , join them in JB's , and have only 1 cable drop down to each fuse / mcb.

its also known as cheating ;-)