Porch Light - Fused spur or Lighting cct?

[Reg_Prescott]

Hi all,

I have a couple of questions regarding my porch light.

What is the preferred method: Connect the light to the existing lighting cct, or add a fused spur from the ring?

The light is currently connected to the lighting cct. But it would be dead easy for me to add a fused spur, since the porch is nest to the garage which has its own ring.

The reason I ask is I am sure that the instructions that came with the light recommended a fused spur not the lighting cct. At the time I could see no reason for this, so I simply replaced the old light with the new one.

What is the thinking behind this? BTW it's a 60W lamp, not a flood light or anything.

Thanks,

Mark

 

[ban-all-sheds]

I've seen that recommendation made before.

IHNFI why they say that.

Where do you want to connect it?

 

[Reg_Prescott]

Thanks for the quick reply!

Both methods are ok OK for me, since the CU and wiring is in the garage and is easily accessible. Adding a fused spur would make the wiring slightly tidier since I have a socket on the ring main close by the light.

I am curious why they suggest a fuse spur. The box if IIRC had a sticker on it saying "meets latest regs" or something simliar. This made me think that for some reason outside lights should be on a fused spur now. Any ideas?

Another Question:

Is it okay to add another lighting cct directly to the MCB? I mean so that two cables enter the MCB rather than a juction box? This is how the connection the light is currently made. The MCB in question only supplies four wall lights in the lounge - and the porch light.

Cheers!

 

[Steve]

perhaps they want it on a spur on a ring because the ring is more likely to be RCD protected than a lighting circuit, and to the manufacturer, this is better as it reduces the risk of electric shock from their fitting to practically zero. Therefore, less likely to get sued etc. Long shot i know, but a possibility.

 

[mapj1]

Also as outdoor fittings are more prone to damage, an easy method of isolation for servicing, and not having the house lights cut off, comes to mind - the reg about being organised for minimum inconvenience in the event of a fault or servicing - I can't rememer the number, but I''m sure someone will, but the one that can also be construed as requireing a final sub-circuit per device !

 

[Jaymack]

OSG P19 refers: -
Disconnection time of not more than 0.4s is required for final circuits supplying: -
3.5.2 (iii) Fixed equipment outside the equipotential zone with accessible
exposed conductive parts.

See also BS 7671 and 471-08-03: -
Where a circuit supplies fixed equipment outside the earthed equipotential zone and the equipment has exposed-conductive-parts which may be touched by a person in contact directly with the general mass of Earth, the earth fault loop impedance shall be such that disconnection occurs within the time stated in Table 41A.

 

[Reg_Prescott]

Thanks for all the feedback. So If I understand correctly, a fuse spur should be used as it means the fitting is also RCD protected

 

[ban-all-sheds]

As long as the circuit you're spurring from has RCD protection, yes.

 

[Reg_Prescott]

Fused spur it is then.

Thanks all. This really is a great resource!