Route Fused Connection Outlet via Light Switch

[Door7000]

Need to power kitchen cabinet lights. It has a transformer and thus switching on at a plug / socket is not suitable.

I have a spur at the top of the cabinets, which I can connect a Fused Connection Outlet to. A few feet away are two existing light switches. Thinking of changing the light switches to a 3 switch like this:

View media item 73948
2.5mm T&E into the Fused Connection
1.0mm T&E out to a junction box
Junction box provides live and return to the 3rd switch
Junction box provides the live return and neutral to the transformer
Fuse in Connection Outlet = 3A
Blue wire on live return sleeved in Brown at the switch terminal and junction box terminal
Light switch is metal and thus needs earth
Flex outlet to transformer is 2core so no earth

Would that comply with regulations?

 

[EFLImpudence]

Yes, if the cables are restrained so they cannot be pulled out of the junction box.

Either by clipping to the surface or something like -
http://www.tlc-direct.co.uk/Products/ASJ501.html

 

[OwainDIYer]

avoid the separate junction box entirely and use terminal strip inside the FCU.

Have you checked for neutrals at the lightswitch?

 

[conny]

avoid the separate junction box entirely and use terminal strip inside the FCU.

Have you checked for neutrals at the lightswitch?

Why check for neutral at the switch? Only needs a single pole, (in the live feed), to be switchable.

 

[Door7000]

So I could use a flex outlet plate instead and do this?

Live In - 2.5mm T&E brown
Netural In - 2.5mm T&E blue
Earth In - - 2.5mm T&E green/yellow

Live Out - 1mm T&E brown cable to light switch
Neutral Out - cabinet lights flex neutral
Terminal block - 1mm T&E blue (brown sleeved) return from the light switch + cabinet lights flex live.

 

[OwainDIYer]

avoid the separate junction box entirely and use terminal strip inside the FCU.

Have you checked for neutrals at the lightswitch?

Why check for neutral at the switch? Only needs a single pole, (in the live feed), to be switchable.

Because if there is a neutral at the switch then that can be used instead of spur off the power circuit

 

[OwainDIYer]

So I could use a flex outlet plate instead and do this?

Live In - 2.5mm T&E brown
Netural In - 2.5mm T&E blue
Earth In - - 2.5mm T&E green/yellow

Live Out - 1mm T&E brown cable to light switch
Neutral Out - cabinet lights flex neutral
Terminal block - 1mm T&E blue (brown sleeved) return from the light switch + cabinet lights flex live.

A FCU with a flex outlet, yes. You still need the fuse.

 

[Door7000]

ok great.

Thanks all for the advice.

 

[AdrianUK]

Just be a little careful. If you do this then you'll need to isolate the power from two different places to make everything in this 3 way switch dead.

Feeding a light switch from the ring via FCU can lead to some nasty surprises for someone who comes along in the future, isolates the lighting circuit and then gets a belt......

 

[PrenticeBoyofDerry]

Other points would be the requirement of RCD protection for any newly installed cable that is not mechanically protected and buried less than 50mm within the fabric of the wall, chases within solid walls should comply to the depth detailed in Part A of the building regulations and cable also should be routed within the permitted safe zones.

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• PrenticeBoyofDerry
• 16 Oct 2011
• 20

So if the circuit does not already have RCD protection you have options of introduction the device at the fuse board/consumer unit for the whole circuit or by means of a composite device that acts both as a fuse connection and a residual current device, which can be used as a substitute for the FCU. Similar to the image below.

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• PrenticeBoyofDerry
• 16 Jun 2012
• 1

This units are quite bulky at the rear of the plate and considerations should be made to fitting a backbox that allows extra space, to accommodate for this.

Part P of the building regulation, requires that reasonable precautions are made in the design and installation, to prevent harmful effects of the installation.
So I would recommend that is precaution is not only proved by design but also by the recommended methods of inspection and testing. The results/finding should then by documented in either a minor works cert or a electrical installation cert.