Does this setup contravene any regs or is it ok?

[westward10]

One light or ten lights, makes no difference. From what the OP has later stated though I don't believe the assessor was actually referencing the Reg in question.

 

[Deleted member 26818]

Some people’s arguement is that to connect two final circuits to the same MCB is a contravention to Reg 314.4.

I think that is not the intention of that reg.

Well to connect two final circuits to a single OCPD would contravene Reg 314.4.
However it becomes a contradiction in terms, because by doing so the two circuits become one circuit as per the definition of a circuit.

 

[Wilko]

I remember (and adhere) to your wise advice of a year or two ago Westy, say as little as possible to Mr A.
Less said, less to repair .

 

[Nigel]

Well to connect two final circuits to a single OCPD would contravene Reg 314.4.
However it becomes a contradiction in terms, because by doing so the two circuits become one circuit as per the definition of a circuit.

I don’t think you understand my point.

 

[westward10]

But the Reg quotes final circuit and not circuit so there must be difference as both are listed in the Definitions.

 

[Deleted member 26818]

It could argued that by having the two parts of the circuit so far apart, a fault affecting one part of the circuit so remote from the other might increase danger or inconvenience?
Not sure that having the two parts so far apart will facilitate safe inspection, testing and maintenance.
The light in the loft stops working, you change the lamp, check out all the wiring in the loft, only to find it’s due to a dodgy bulb in the lobby.

 

[Deleted member 26818]

But the Reg quotes final circuit and not circuit so there must be difference as both are listed in the Definitions.

It makes reference to final circuits, to distinguish them from distribution circuits which don’t need to be connected to a separate way in a DB.
It also prevents people from describing part of a circuit protected by an FCU as being a separate circuit.

 

[Wes1000]

It could argued that by having the two parts of the circuit so far apart, a fault affecting one part of the circuit so remote from the other might increase danger or inconvenience?
Not sure that having the two parts so far apart will facilitate safe inspection, testing and maintenance.
The light in the loft stops working, you change the lamp, check out all the wiring in the loft, only to find it’s due to a dodgy bulb in the lobby.

Just to make it more clear. The property is a rather large single story building and the lobby is central to the building and loft directly above.
Originally I intended to have the circuits separate but thought nothing was wrong with combining the two as it’s still only three lights and being single story it’s similar to supplying a loft light from an upstairs lighting circuit.

Regards separation of circuits for nuisance tripping, I already have 6 lighting circuits, 3 on each RCCB (dual RCD board and not RCBO board, I know! But that’s a different argument and was down to expense).

 

[Deleted member 26818]

Whose decision was it to opt for the cheaper dual RCD configuration?
If it was the client’s, then they can hardly complain about lack of spare ways when 4 ways are being taken up by the RCDs.

 

[Wes1000]

Whose decision was it to opt for the cheaper dual RCD configuration?
If it was the client’s, then they can hardly complain about lack of spare ways when 4 ways are being taken up by the RCDs.

It was the clients choice. I gave them the options but they opted for splashing out on all the trick bits instead.

Just can’t convince some people.

 

[sam400]

That’s ridiculous!
I don’t think there is anything wrong with it nor is it bad practice! As long as it’s labeled correctly,
I think you had better make sure every accessory in the house has it’s own radial and OCPD to be on the safe side then get him back.

Have you got to pay for a revisit?

 

[Wes1000]

Deleted

 

[Wes1000]

No revisit. Did it while he was there.

 

[Wes1000]

Wow 4 messages in one go. Never done that before. Normally that’s @Pete999 trick.

 

[buzzlightyear]

I like an assessor who knows his stuff

mmmm, let me think about that, no. the regulations are guide ,not the f88king holly bible .

 

[Toneyz]

I don't know why you didn't rewire it to the lobby lighting circuit unless impractical. Shouldn't be the need to double up to give spare ways poor design.

 

[Wes1000]

I don't know why you didn't rewire it to the lobby lighting circuit unless impractical. Shouldn't be the need to double up to give spare ways poor design.

There was spare ways just thought I’d free up another one and connect the two at the board.
The way it’s set up the cable run to the board compared to coming from the lobby light is about the same.

 

[Des 56]

I imagine he would have conniptions if he (assessor) saw some of the multi light circuits and RFC with comms sockets connected at MCB that I regularly see then. I can't see why the loft light was not put up on the upstairs lighting in the first place. Someone wasn't thinking, one light on a 6a MCB could be argued to be not taking account of the sections referred to in 314.x.x i.e. OCPD. I can't see any of the stipulations from i-iv have been breached though. But it is very on the "raggedy edge" arguing the point. So the assessor could be asked what he makes of OCPD for one LED light (4-7w) 7/230 =0.03 A, does that make sense?

A different viewpoint could argue that Granny (who often falls down the stairs when all the lights go out because they are on one mcb) may be more content knowing that she is not going to be totally in the dark when that pesky up lighting pops again whilst she's in the attic

 

[a-z electrics]

Its no different than running a spur from a rfc mcb, or 2 spurs from an mcb. Ive seen this listed as perfectly acceptible somewhere in ECA Q and A session but couldnt quote where..
Stick to yr guns and tell assessor where to stick his tick list!

 

[Jjc]

I’ve just done a large job where I fitted a double stack board (23 ways) and by the time I’d finished we only had two spare ways left in the board. So I thought that I’d free up one more by moving the lighting circuit for the loft on to the lobby lighting circuit at the CCU so both circuits are now on the one 6A MCB. Other than that they are totally separate. They also only contain one light for the loft and two lights for the lobby (all LED’s)

To me this is no different from taking the supply from the last lobby light to the loft and actually might make it easier to find a fault if you could separate it at the board rather than mess about behind down lights.

All was good until I decided to use this job for my Stroma visit.....
I was told that in no way can I do this and I need to correct it or it will go down as a non conformity. After arguing the point for 10 minuets I gave in and put the other MCB in and moved the loft light on to its own circuit and all was peaceful again.

Who’s right here?

Don't you need to leave a certain percentage of spare ways for future use?

 

[Jjc]

So how is this any different from say connecting a spur to a ring final from the MCB? Or installing say some hardwired smokes and taking a supply cable from a lighting MCB?

You're not wrong, the assessor is just being a super picky d1ck!

One, two, three, four cables leaving an MCB... it's not the cables that define what a particular circuit is, it's the MCB labelling. If it says Lobby and Attic Lighting, and it has one cable going up to the attic and one to the lobby, then whats the problem?

How would you record the Zs... you'd do what you do for any other circuit... test at each point and record the highest value.

How then do you know which cable is for which circuit?