Replacing fused spur

[stevepbuk]

hi,

I am in the process of installing some lighting in a utility room. I am going to use led strip lights above and at the bottom of the units and some triangle shaped bench lights above the unit benches. Ideally I want the bench units and the strip lights switched independantly, however there is only one fused spur on the wall to support this. Would it be acceptible to replace the fused spur to be a double light switch ( I would run a second cable behind the unit to support this ) and then install unswitched fused spurs above the units where all the transformers etc are.

Any help would be greatly appreciated.

Cheers

 

[PrenticeBoyofDerry]

The fused spur must be there for a reason, I guess to down fuse a circuit, if that was the case I would think it would be best not to replace with an accessory rated at less than the circuit protective device.
You have options though, but need more info on what purpose the FCU serves?

 

[stevepbuk]

Hi, the fused spur was originally put there to support old style hallogen lighing in the cabinet. From the fused spur the wire runs up to the top of the units and into a junction box to the various lights. I am removing the old lights so the only thing that will be driven from the switches will be the new lighting.

Cheers

 

[PrenticeBoyofDerry]

But from were does the source of the supply come from? I guess a socket circuit? If so, then it must stay in place to down fuse the circuits to lighting.
You maybe able to change it over to grid switch set-up including fuse module and two switches. Or move the FCU closer to the socket it is taken from then feed a two gang switch from there.
Do you have RCD protected circuits?

 

[stevepbuk]

Yes sorry it comes from a double socket that is sits next to the existing fused spur that Im wanting to change. If I ran from the switches ( that would replace the fused spur ) and put fused spurs before going to any lighting transformers would this not achieve the same?. The only reason I was quizzing is the ampage of the light switches I have looked at are all 10amp max.

I have looked at the modules and you couldnt find a configuration that would allow me to get two switches and a fuse module within a normal single socket sizing.

Also, I had a new MCU installed last year and all circuits have their own dedicated RCD ( RCBO I think they are called ).


Thanks for your help.

 

[deadshort]

Hi, yes you would require a 2g box, but it would look neater than a non-switched spur and 2g switch

Regards,

DS

 

[stevepbuk]

Hi, I was hoping to get away with a 1g box as the wall is tiled. What I was hoping is that I could wire up from the existing socket to a double light switch ( 1 gang ) that would replace the existing fused spur. I would then have a wire from each of the switches up to above the cabinets where I would connect each up to a non switched fused spur and then to the lighting transformer etc.

Thanks

 

[deadshort]

Hi, do you have 2 separate cables leaving the existing fcu? As has been advised, you must retain the fusing down BEFORE the 2g switch.

Regards,

DS

 

[JohnW2]

Hi, I was hoping to get away with a 1g box as the wall is tiled. What I was hoping is that I could wire up from the existing socket to a double light switch ( 1 gang ) that would replace the existing fused spur. I would then have a wire from each of the switches up to above the cabinets where I would connect each up to a non switched fused spur and then to the lighting transformer etc.

I presume that the concern expressed by PBoD related to the fact that standard light switches are not 'rated' for the currents that could theoretically be supplied by a sockets circuit, but (if I understand correctly that the existing FCU is a spur from a double socket) I personally would not be particularly concerned about that if there were to be FCUs downstream of both switches. However, if one did have concerns, they could be partially addressed by using two 20A grid switches (which would fit on a 1-gang plate), rather than a standard 2-gang light switch; 20A is still less than the probable 32A capacity of the sockets circuit, but it would be a step in the right direction as compared with a (probable "10A") 2-gang light switch.

However, what I don't really understand (maybe I'm missing something!) is why you don't just keep the current FCU (either changing it to an unswitched one or just 'ignoring' the switch, leaving it always on) and use that to feed your two light switches.

Kind Regards, John

 

[ban-all-sheds]

If I ran from the switches ( that would replace the fused spur )

They may not.

 

[stevepbuk]

Hi thanks for that.

The only reason that I want two individual switches is that the power supply for the strip lighting is 100w and it means everytime we want only the under cabinet lighting on, the transformer will be powered up but not powering anything.

Regarding the switched left on and powering two switches I have no where else to put the light switches that is easily accesible as the cabling goes behind the cabinet and up to the top of the cabinets where the transformers etc are. The wall is tiled which makes things even harder.

Cheers

 

[JohnW2]

Hi thanks for that. The only reason that I want two individual switches is that the power supply for the strip lighting is 100w and it means everytime we want only the under cabinet lighting on, the transformer will be powered up but not powering anything.

Fair enough - and, in any event, I wasn't actually questioning you wish to have two switches.

Regarding the switched left on and powering two switches I have no where else to put the light switches that is easily accesible as the cabling goes behind the cabinet and up to the top of the cabinets where the transformers etc are. The wall is tiled which makes things even harder.

Again, fair enough. I see the problem. I guess that leaves you either taking the "official line" advice you are being given that you theoretically should not connect (probably 10A) light switches to a (probably) 32A sockets circuit (in which case I don't know what your solution would be), or else adopting my somewhat more pragmatic view that I would personally not be concerned about that if, as you propose, there were FCUs downstream of both switches!

Kind Regards, John

 

[deadshort]

Hi, do you have 2 separate cables leaving the existing fcu? As has been advised, you must retain the fusing down BEFORE the 2g switch.

Regards,

DS

The reason for my question was simply to offer a potential solution to the problem.
If you have two cables leaving the fcu i.e. 4 wires you could use 2 as switch wires and 1 as a feed by fitting a join box on the top of the cupboard taking a lighting supply to the join box on the top of the cupboards.\\

The feed to the existing fcu would be redundant and disconnected at the back of the socket it's spurred from.

DS

 

[PrenticeBoyofDerry]

Firstly can you clarify that you already have in place the switch cables required for the two gang light function?
And if so what CSA are they, as I personally would not put underrated accessories and cables in to service.

 

[stevepbuk]

Hi, one of the cables is already through and is 2.5mm t+e. I can get another cable through should I be able to add a double switch as discussed.

Thanks

Steve