5 cables, 2 ways & a garage fuse box

[Mega Greg]

Anyone got any thoughts on this?



I've got a job to do installing an additional fluorescent (to provide localised light for a work area) in the context of this seemingly crowded installation.

The cables running from of the top of the fusebox are (from left to right) -

Left knockout:

1 Power supply for 1 × RCD socket

2 Lighting (main light - cables run right)

3 Lighting (outside light on sensor - cables run right)

Right knockout

4 Lighting (outside light on timer and one way switch - cables run left)

5 Power supply for 2 × RCD sockets in parallel (and installed in direction of 1 above)

I've got to admit that I can see some advantages of the wiring system previously installed. Despite the power and lighting cables coming out of different knockouts the doubling and trebling up of cables gives the electricity more wire in which to move and, with the open grommets used in the fusebox getting packed out, there's less opportunity for the minimal dust of the garage to settle inside.

Big colour changing book says:

341.2 Separate circuits shall be provided for parts of the installation which need to be controlled, in such a way that those circuits are not affected by the failure of other circuits, and due account shall be taken of the consequences of any single protective device.

I've seen this reg used to justify one wire one breaker but I'm now thinking that it has a clearer application against errors such as the placement of the two ends of a ring circuit in separate breakers.

For sure, if the junction of the lighting cables was raised 500mm from the crowded fusebox shown and into a separate junction box then the fusebox would be a lot neater but this would serve to add two more terminations to the installation. Rewiring the fuse box would also give the opportunity to install closed grommets with slits cut for the cable runs to guard against dust.

I'm really interested in best practice in a situation like this. In a large CU I'd like to stick to one cable to one breaker just to keep things clear but in a small garage set up I can see the argument for one knock out one breaker.

Anything I'm missing.

Greg

 

[telectrix]

i'd take the lighting completely out of the board and fit a din rail adaptable box, fed with a single 1.5mm from the board, then connect new circuit into that.

 

[i=p/u]

yo can take extra points from the origin of the circuit as long as you aint over loading it. you might be better just taking from light fitting to other light fitting.

 

[Mega Greg]

i'd take the lighting completely out of the board and fit a din rail adaptable box, fed with a single 1.5mm from the board, then connect new circuit into that.

Thanks telectrix

Is this for to try for neater cable management or for another reason?

 

[telectrix]

neater, easier, bear in mind that the lighting is still only 1 circuit.

 

[Mega Greg]

yo can take extra points from the origin of the circuit as long as you aint over loading it. you might be better just taking from light fitting to other light fitting.

Thanks i

I'll take that as a borderline vote for reducing no of cables out of the fusebox. Your term "origin of the circuit" also helps.

In the current case got a problem in going from light to light. The light switch nearest the fusebox has its conduit stuffed with a loop in cable from the fuse box, strapper cables to a second switch and a loop out to the light. In other cases, and if the lighting controls weren't as scattered about, I'd agree.