Wiring for a PIR outside light

[Happyunited]

Hi all, new to this place so please go easy on me

Right I want to install a new PIR light outside my front door. I dont have a switch for it and I dont need one either as the light will come on and off when I need it to (in theory).

1) Is it ok to run a wire straight from the loft to my new light without a light switch?

2) I am guessing I will need a FCU somewhere along the new wire route is this correct?

3) Is it ok to just break into the wiring main in the loft space using a junction box?

Many thanks in advance for your help.

 

[Taylortwocities]

1) Is it ok to run a wire straight from the loft to my new light without a light switch?
You should have a isolation switch, somewhere accessible.

2) I am guessing I will need a FCU somewhere along the new wire route is this correct?
What circuit would you be running the light from? You shouldn't need an FCU if you connect in to a lighting circuit.

3) Is it ok to just break into the wiring main in the loft space using a junction box?
Yes but the junction box will have to be accessible and suitable sized for the circuit you are connecting to. In a loft you will probably only find lighting circuits, unless you live ina bungalow

 

[Happyunited]

1) Is it ok to run a wire straight from the loft to my new light without a light switch?
You should have a isolation switch, somewhere accessible.

2) I am guessing I will need a FCU somewhere along the new wire route is this correct?
What circuit would you be running the light from? You shouldn't need an FCU if you connect in to a lighting circuit.

3) Is it ok to just break into the wiring main in the loft space using a junction box?
Yes but the junction box will have to be accessible and suitable sized for the circuit you are connecting to. In a loft you will probably only find lighting circuits, unless you live ina bungalow

Thank you for your quick reply.

You are right, its all light circuits in the loft so its ok to just break into one of those circuits? Do I need a junction box or will one of those block connections do the trick?

The route that which I am going to run the cable is pretty straight forward and I dont have anywhere to easily put a light switch.

Is it essential that I have a light switch? Will the light work ok without the light switch?

Thanks again

 

[Click-Sure]

Yep, its definately outside light season once again!

As TTC, but I'd ask you to remember that the term 'accessible' for a junction box and for a switch if different.

A junction box will very rarely need to be accessed, and never in any kind of hurry, so somewhere in the loft would be fine.

A switch, however will need to be accessed much more often, even if you do say you wont really need one, what if its snowing and the damn outside lights keep coming on? Also, if there was a problem with the PIR or light fitting that meant quick isolation until you could get to the fuse box.

 

[Click-Sure]

Block connectors will not do, as you'll have uninsulated live parts kicking around, not good in a dim loft.

'Insulation' tape will not do either, as it can be removed without a tool.

A round 20A junction box (properly secured) will do nicely. (I say 20A as they are much roomier than a 5A rated one)

 

[Happyunited]

Block connectors will not do, as you'll have uninsulated live parts kicking around, not good in a dim loft.

'Insulation' tape will not do either, as it can be removed without a tool.

A round 20A junction box (properly secured) will do nicely. (I say 20A as they are much roomier than a 5A rated one)

OK. A 20A junction box is what I will use. This is what I was going to use anyway I was thinking of securing this to one of the joists in the attic.

I have looked around and putting a new switch in will cause me a hell of a lot of work that I dont need to be honest. I understand what you're saying about snow etc but will the light work if its wired directly to the light circuit? I understand the isolation aspect but I guess I would have to get into the attic if I needed to isolate it.

It doesnt need a switch to work does it?

Thanks again

 

[Click-Sure]

No comment.

You need a switch, regardless of wether it would work with or without one or not, it is a requirement of the regs.

 

[Happyunited]

No comment.

You need a switch, regardless of wether it would work with or without one or not, it is a requirement of the regs.

Ok. So in theory I could have the switch in the attic somewhere after the junction box? The light I am buying will go on/off when I need it to so I am pretty sure I wont need a switch somewhere where I can access it easily.

Thanks for your help.

 

[Taylortwocities]

It will go on/off when it wants to, not necessarily when you want it to!

You could fit an external switch on the wall near the light.

 

[Happyunited]

OK Just a quick update.

Finally got round to sorting out the light this weekend and I have a bit of a problem.

Got the light up all looks well, got the switch in place etc put just need to break into a circuit to power the thing.

I was going to drop a cable down from the loft as I have a fairly straight root but I have noticed a cable I can break into but it turns out this cable is for my spa bath and has its own 30A fuse in the fuse box.

Can I tap into this cable or is it way too high a fuse for a PIR light?

Should the spa bath be on a 30A fuse yes?

Thanks for your help.

 

[Happyunited]

Can anyone answer my question?

Many thanks

 

[stargazer]

Without knowing the details of your spa bath circuit I would be loath to suggest you tap into that.
Is there not a lighting cable up there you can tap with your 20 Amp junction box? Make sure it is a live loop cable and not a switched live before you cut into it!

got the switch in place

Excellent. Where did you put it?

 

[Peter1919]

I'm no electrician but I would say you can't use a supply to a Spa bath to connect in a light. I would break into the lighting circuits in the loft as you originally planned

 

[Taylortwocities]

Can anyone answer my question?

Regretably, many of the regular contributors are out earning a crust during the day so please don't expect an instant response to questions.

 

[Happyunited]

Right all up and kinda working.

The timing of it seems to be a little messed up, I think the unit may be faulty as I have turned the timer dial to all the positions but yet it seems to stay in for over 3 mins, it says it should stay on anything from 5secs to 7mins!!!

Also does the switch have to be in on position for it to work? What if I want to have the light on constant and not on the sensor? Is this possible?

The sensor distance seems to work alright.

I'll try and get the diagram up with the way I wired it.

I will also get some pics of my handy work up