FCU on a lighting circuit

[bel83]

Hi Guys,

Please could someone throw some help in my general direction?!

We've been rewiring our house under the supervision of a qualified sparky as I want to become an electrician. However he has gone on holiday for 2 weeks and has left me a list of things to get done in his absence. Nothing is connected to a CSU so there's no risk in that regard and he's also checking everything meticulously when he gets back.

We've got three outside lights, all in the same set up (i.e. they're part of the main lighting radial and attached to a switch). He has recommended that we future proof them by attaching switched FCUs to the circuit, in case at some point we want PIRs. They are already wired to a switch as we are going to put the FCUs up at ceiling height.

I'm trying to work out how I need to wire this in. I understand it from a socket, and without a separate light switch, but I'm struggling to work it out from it coming off the lighting radial. I think I have it sorted and then get myself in a muddle. We are using a wago box in the wall space to limit the number of wires having to go out of the house.

The picture is what I think I need to do... but I keep changing my mind between the FCU connecting to the switch or to the WAGO.. because somewhere a circuit line gets discontinued.. and now I'm thinking I need 3 core.. connect the neutral line in the FCU with terminal block, extend a switched live and a com.. do the same in the switch? and again extend the switched live and comm to the WAGO and on to the luminere?

http://www.dropbox.com/s/0xy7rx9204q9bh6/electrics.png



Please could someone advise. And before you all have a go at me for not being qualified.. I am doing this with an electrician. He'll check it all when he's back but I need it in place for him to do it..

Thanks in advance..

 

[bel83]

rather than being unhelpful maybe suggest what you're not understanding and offer help...?

 

[Spoon]

So what you are saying is that you are going to add 3 outside lights to the lighting circuit?
So why do you need FCU's?
What is the wattage of the outside lights?
If you buy PIR lights can't you buy the LED ones?

 

[Simonslimline]

It would be a good idea to have double pole isolation for the outside lights. That way if a fault occurs you can isolate the neutral as well.

 

[trev]

I'm with Spoon on this, you can buy LED flood lights with PIRs.

 

[bel83]

basically our outside lights are wired into the lighting circuit and all have individual switches (not FCUs). Our electrician came to wire things in last week and said that as they are PIR they need to be on FCUs. We are replacing the lights with non PIR lights anyway (10W LEDs) but he said that to future proof them (in case we want PIRs in the future) and in order to isolate them, we have to have each one on a FCU.

We have put non maintained junction boxes in the wall spaces so only the power cable to the light goes outside. Without the FCU these are wired the same as any other junction box or ceiling rose, i,e, line in and out, switched live and comm from the switch and the neutral and live from the light. However, I don't know where I need to put the FCU in- is it before or after the switch.. I assume before, so that all power in is cut off.

if so, do I need 3core to connect it to the switch so that comm/ live/ neutral connections are maintained, or am I missing something? I get what I need to do if I was connecting it as a spur from a socket. I think the whole 'double switching' element is the bit that's confusing me..

@Carlos- you're really not being any more helpful. If you have nothing useful to say, go and bother somebody else.
@Spon- thank you. As to why we need FCUs, who knows. Like I said, he has said futureproofing..

 

[Deleted member 72666]

Did you not think to ask your 'holidaying' sparky friend before he went away?

 

[bel83]

unfortunately he was in a bit of a rush.. we'd previously come to the decision that we didn't need them as we weren't having PIRs and then he changed his mind and said to put them in just in case we changed our minds in the future.

@stan- I take it that this means that you think I'm bullsh*tting about having a sparky in.. think what you like.. We started this with the intention of having one sign off stuff after we'd installed as my f-i-l is an electrical engineer but was never domestic and things have moved on rather, so i said that i wanted it all to regs etc. The sparky is a friend of a friend and has agreed that so long as he oversees every step and has conversations with us about plans, he's happy to come and test etc. He was impressed with how fast i grasped what i was doing and was confident in my abilities. We both assumed that I knew what I was doing with the FCU, and like I said, if there was no switch already in the line, then this would make more sense to me.. Doing it as a 3 way switch won't work according to my logic as the point is to isolate it..

Please could someone actually offer me some help, as opposed to just questioning my honesty.

He's back on the 31st so I can ask him before he comes to test but I'd much rather have it sorted as I'm renovating the whole house and don't really want to get caught up on this..

Thanks

 

[Spoon]

Hi mate.
In your case above you would only use the FCU for isolation & maintenance.
Therefore put the FCU in where you would think it would go. Any electrician should know where it goes.
I'm not giving you the full answer cause really you should now know.

 

[bel83]

Hi Spoon,

Thanks.. Can I just clarify this with you- If it's there purely for isolation and maintenance it should cut the power to the permanent live. So therefore I want it to go in before the switch.

I understand your reticence to reply completely.. And like I said, if it's in the wrong place he'll take it out and put it where it needs to be when he comes to connect it all.. I'm essentially minimising the time spent on bits he has to do..

Cheers

 

[DPG]

Seems a bit over the top having individual isolation for each outside light. Or is it just me? Daz

 

[Spoon]

If it's there purely for isolation and maintenance it should cut the power to the permanent live.

Read post 6 mate.

 

[bel83]

My original diagram, which my husband questioned, causing my head spin was as follows...

Lighting radial in- FCU- Non maintained connection unit- leading (separately) to the switch and the light itself.

I believe that is right... (she says, hopefully!)

 

[bel83]

and yes.. on the neutral.. sorry Spoon! i tell you, head spin.. trying to do audits while working this out too.. no electric at home so no wifi!! and yes.. it does seem ott but they're in very different places so unless they had a radial all to themselves (which in hindsight would have made things SO much easier.. ) they need them if they are to be isolated..

 

[Spoon]

Does the outside light manual say that it need isolation?