10w led floodlight /protection

[joehat]

Hi all

Question 1

Is a flood light omitted from over current protection?
I normally go a lighting circuit but this job would be a lot easier if coming from the outside socket, which is part of the ring,
As this is fixed, would it be okay to wire it in 1mm or 1.5mm flex, without over current protection, eg like a spur I guess as this doesn't.

Question 2

Would you be happy feeding a 10w led flood light from a sour socket, as its such a small load?

I would say yes to both but I've had people say no you can't .

 

[Andy78]

You are right it would be easier. Just as it would be easier to bodge most jobs, it just wouldn't be right.

 

[davesparks]

No an LED flood is not omitted from overcurrent protection.

 

[joehat]

But can't it be omitted if it's a fixed current aplience? , and it's also such a low load?

 

[joehat]

For example a spur socket is omitted? As in the mcb would be 32a yet the cable could be rated less than 20a in certain install meathods?

 

[Andy78]

For example a spur socket is omitted? As in the mcb would be 32a yet the cable could be rated less than 20a in certain install meathods?

If the installed cable was derated to less than 20A on a 32A circuit, even a ring, then the circuit would have not been designed properly.

 

[Dave OCD]

You could fit a weatherproof FCU adjacent to the external socket and connect the light to that using a 3 amp fuse, even a 1 amp would be fine.

 

[Octopus]

Why can't you fit a fused spur?

 

[Darkwood]

Isolation requirements for adjustment, general maintenance etc
Reduction in cable size on the ring would require appropriate down fusing over 3m ( Supplying fixed load )
Zs would still need to comply (You have reduced the earth size thus increased the Zs Value against the 32amp mcb/rcbo)

Yes in theory you could wire direct to a 32amp mcb in the board with 1mm cable but as you are asking about tapping onto a ring then you have other regulations to consider here, with the exception of socket circuits, most house circuits can be classed as fixed loads if you know the max' demand possible, we of course don't do this in practice in domestic as its not the done thing and can be very confusing to others who follow so we all tend to design and wire without using the omittance clause.

If the light was within a 3m run of a socket it was tapped off then yes you could argue it is within regulation to do this but just from a maintenance aspect, I would be running it through a suitable Sw/F spur. Also to note, the manufacturers instructions may require fusing down but this is manufacturer dependent.

In my sector this clause comes into its own as I use it regular when allowing larger breakers to counter nuisance tripping due to inrush on fixed load equipment.. this be more the targeted application of this regulation.

Personally in my opinion, you shouldn't be looking to use this clause in domestic like in your example, add a fused spur as is the general practiced method.

 

[joehat]

What about in 2.5mm flex? Like a double socket spur ?

 

[Octopus]

Why can't you fit a fused spur?

I'll try again. lol

 

[uksparks]

The spur via a FCU, your max Zs would change as it would be protected by the 1362 fuse in the FCU so the max Zs for the light via a 3A fuse is something like 17ohms

 

[Leesparkykent]

The spur via a FCU, your max Zs would change as it would be protected by the 1362 fuse in the FCU so the max Zs for the light via a 3A fuse is something like 17ohms

no it wouldn't as you would spurring of the Ring final circuit to add the FCU in so the OCPD recorded on the minor works would be the one in the board.

 

[joehat]

What about in 2.5mm flex? Like a double socket spur ?

Customer wants least mess possible, and isn't doing it in 2.5 the same as an infused spur Anyways??
In the osg it states an unfused spur can be one single or double socket or one perminately connected appliance ?

 

[Andy78]

Customer wants least mess possible, and isn't doing it in 2.5 the same as an infused spur Anyways??
In the osg it states an unfused spur can be one single or double socket or one perminately connected appliance ?

What's messy about a suitably IP rated FCU close coupled to the outdoor socket ? Has it been confirmed that the outdoor socket is within the RFC properly as it is common practice to spur off for an outdoor socket addition ?