Fuse size in switched FCU

[garrymum]

Hi

I am in the process of installing a 150w outside security light. I am putting a 5A JB into the upstairs lighting circuit and running a spur from this to a switched FCU which will feed the outside light. My question is - what size fuse do I need in the FCU? Currently it has a 13A in which I guess is far too big.

TIA

 

[davy_owen_88]

3A will be fine. I hope the junction box will be accessible?

 

[garrymum]

3A will be fine. I hope the junction box will be accessible?

Thanks. Define accessible? It will be in the loft screwed to a joist. There is no loft boarding in that area of the loft so I would class it as accessible. If the JB was not accessible, does this drop into part P territory?

TIA

 

[davy_owen_88]

In the loft is fine. Part P would not apply regardless of accessibility but BS7671 states that all screwed connections must be accessible, which is not the case, IMO, for JB's underneath floorboards etc.

On the other hand, Part P may apply to the addition of the outdoor light. I believe if the cable enters the fitting directly then it is not notifiable, but if there are exposed cable runs outside then it is...

 

[garrymum]

Thank you

 

[kai]

Having a neon indicator in the FCU for the outside light is useful too.

Suggest placing the switch in the downstairs hallway, label it "Outside Lighting", and have it visible from the front door.

 

[garrymum]

On the other hand, Part P may apply to the addition of the outdoor light. I believe if the cable enters the fitting directly then it is not notifiable, but if there are exposed cable runs outside then it is...

The cables directly enters the security light from behind. No visible cable anywhere.