How about this for lights in 1 room

[oharaf]

Have been asked to supply...........................

1 - 2way central ceiling light (with fan)

7 wall lights

15 spots

wall lights on 1 switch

spots on 1 switch

Used to be an old shop now going to be a living room

Only 1 feed into the room!!!


The room has its own designated lighting circuit/ MCB (TFFT!!)

Room is approx 6m by 4m


Any advice before I get on with the job guys?

Seems to be alot of lights for one room, they obviously don't intend to use

them all at the same time (I checked this as soon as they asked!!!!) but i

suppose there is always the chance they might

Have already decided to install I complete new feed after investigating the

previous lighting circuit(s) and discovering that bodgit McGraw had been ther elong before me


There will be some pics to come!!!!

Was nice to find CU with RCD protecting the whole installation

Thou on closer inspection some one has spilt a tin of spaghetti into it and quite a few un-terminated phase and earths

Will require attention

 

[pompeygit]

think if it were my front room i would have spots and wall lights on 2 gang as a minimum. at least that would give 4 levels of lighting.

 

[sparkyspike]

If you're running a new feed, then why not run two?

 

[Lectrician]

Yup, I would run two for sure.

What are you going to do about the RCD incommer?

 

[Click-Sure]

Not a time delayed 100mA S-Type, installed in a TT system?

 

[oharaf]

Sorry clicksure, the incommer isn't an RCD, all the circuits are on an RCD

The spots will be on 2 gang

I thought about bringing in a second feed, having done the calculations it appears that 1 feed will do

However, if I get any problems following T&I the process of spliting into 2 seperate circuits is relatively simple and will take little time to do

 

[Lectrician]

Having two circuits is not just a consideration due to loading....

What do you mean, "The incomer is not an RCD, but all circuits are on an RCD"? Not sure I follow exactly...

 

[oharaf]

Let me clarify Lectrician

The supply is TN-S, the cu has a double pole isolator, all the circuits in the cu are protected by a 30mA RCD

Can't really put it any clearer than that.

I agree the consideration is not purely down to loading, however after discussing with the customer and satisfying myself that the circuit is more than capable of the demand that it could possibly be placed under and taking into consideration voltage drop and all other factors I am happy with the installation I intend to carryout.

Bearing in mind that the lighting circuit is larger than your average domestic installation for 1 room I have designed it so that if need be on complettion of Inspection, Testing and commisioning I am not entirely satisfied of its integrity then I can VERY easily add a second circuit

 

[17thman]

all circuits protected by 1 rcd seems a little inconvienient for all the other circuits in the event of a trip.

 

[oharaf]

True 17thman, but they don't want a new cu, TBF it is in good nick (installed around 2004) just needs tidying up.

If they don't want it, I won't do it, it is not unsafe, just probably inconvinient.

 

[Taylortwocities]

And contravenes BS7671 (16th and 17th).
You cant have the who installation going off when the RCD trips.

 

[oharaf]

Good point Taylor, forgot that bit

So their options really are:



1. New dual RCD CU

2. mechanically protected and earthed lighting circuit

 

[sparkyspike]

If it's that easy to fun a second feed then do it. You're overloaded otherwise and you don't need test results to prove it.

 

[sparkyspike]

1. New dual RCD CU

2. mechanically protected and earthed lighting circuit

Or replace MCBs with RCBOs and lose the RCD.
Or convert the board into a split load and use half RCBOs and half RCD which is cheaper.

 

[oharaf]

Judging by number of RCBO's that would be required a new dual RCD will be cheaper!!!!