Can a junction box throw out a PIR?

[jjrules2]

Hi,

Unfortunately during the installation my client moved the position he wanted a PIR light, meaning even with excess cable and due to the progress of the house, I had to joint box a cable to extend to the new location.

So, the wiring goes like this.

CCU to switch - twin and earth
Switch to Junction box - three core and earth
Junction Box to PIR light one (one that moved) - three core and earth
Junction box to PIR lights two and three - Three core and earth

So basically I did take a 3c and earth from the switch to light one, back out to light two, ending at light three. But due to the moving location I had to install the joint box. Now I have installed the PIR lights and they remain permantly on when wired like this -

Switch -

Live from twin and earth goes in common with permanant (black) to lights
Neutral goes in connector block at back of switch box with grey to lights
Same with earth
Brown switched live from lights goes on it's own in L1.

Switch does nothing when turning on and off unless you remove the permanant live, then the switch works fine. But I have wired these up at work like this and the PIR works when dark and movement is detected, or if you turn the switch on!

Any help would be appreciated, i'm sure i'll get the sarcastic immature comments from the old boys as well :wink_smile:

 

[ackbarthestar]

Why?
I really don't get that statement, though I have seen it elsewhere.

Black and grey are both phase colours now, so it make zero difference which you choose. Given the legacy of black = neutral = safer if anything it ought to be encouraged!

I think its unwise to follow this legacy and continue to use black as a neutral as the whole of Europe, with whom we are in the process of establishing a free trade agreement, utilise blue.
We also use blue, so I would think that grey appears to have a closer resemblance to blue than black.

 

[pc1966]

I think its unwise to follow this legacy and continue to use black as a neutral as the whole of Europe, with whom we are in the process of establishing a free trade agreement, utilise blue.
We also use blue, so I would think that grey appears to have a closer resemblance to blue than black.

Err, last I heard we were undoing our trade arrangements with Europe...

We use blue when it is available, of course, as nothing else would make sense. But what about Europe when they have only the 3 phase-colours and no neutral? Is there a standard for it?

I suspect it is like the permanent-live / switched-live colouring where every permutation is used. You just hope it is the same permutation used throughout a given installation...

So it comes back to my original point - it matter not if you use black or grey as it is not a neutral colour anyway and both are phase colours (here and in the EU). It should be sleeved blue (or clearly marked) in any case so the actual colour reuse is immaterial.

The "don't use black because it looks like our old colours" arguments makes no sense. You can also argue that grey looks more like green.

 

[ackbarthestar]

Err, last I heard we were undoing our trade arrangements with Europe...

We use blue when it is available, of course, as nothing else would make sense. But what about Europe when they have only the 3 phase-colours and no neutral? Is there a standard for it?

I suspect it is like the permanent-live / switched-live colouring where every permutation is used. You just hope it is the same permutation used throughout a given installation...

So it comes back to my original point - it matter not if you use black or grey as it is not a neutral colour anyway and both are phase colours (here and in the EU). It should be sleeved blue (or clearly marked) in any case so the actual colour reuse is immaterial.

The "don't use black because it looks like our old colours" arguments makes no sense. You can also argue that grey looks more like green.

I don't think we are letting go of any trade agreements with Europe, rather we are extracting ourselves from becoming a united states with Europe. Basically we want trade, not union.

As for colour coding the conductor insulation, I might want to be consistent when training our 'apprentices'. So I would follow BS7671 App.7 table 7B for single phase systems.

 

[pc1966]

As for colour coding the conductor insulation, I might want to be consistent when training our 'apprentices'. So I would follow BS7671 App.7 table 7B for single phase systems.

Of course, all new single phase installations use brown & blue for L&N when possible.

But when given a cable with just the three-phase colours (i.e. no blue present for neutral use) such as 3-core SWA, etc, why not re-use black as neutral and grey as CPC (both suitably sleeved)?

The argument about "de-neutralising black" is utter rubbish as apprentices have to know red & black are the old L&N colour anyway. After all, they are going to be repairing and extending system featuring those colours quite possibly for the rest of their working life given how long some installations last!

 

[7029 dave]

Why?

I really don't get that statement, though I have seen it elsewhere.

Black and grey are both phase colours now, so it make zero difference which you choose. Given the legacy of black = neutral = safer if anything it ought to be encouraged!

I would use black to as N, old habits die hard.

 

[Timbo]

Hooray! Another ancient thread resurrection!
Congratulations.

 

[DefyG]

Hooray! Another ancient thread resurrection!
Congratulations.

mmm! 2013 this thread started!! About time it was killed off and a new one started!

 

[Lucien Nunes]

Before harmonisation, in a cable with three insulated cores in the three phase colours R/Y/B, the L3 colour (blue) was normally used as neutral in a single-phase application. With a harmonised cable, it makes most sense to me to continue using the L3 colour (grey) as neutral in single-phase work. Then, where old and new cables meet, it doesn't matter whether the application is single or 3-phase, the colours match L1-L1, L2-L2 and L3-L3.

If the black of a harmonised cable is used as neutral instead, one has to remember in a single-phase application to interchange L2-L3 and L3-L2 colours at the interface.

 

[pc1966]

Before harmonisation, in a cable with three insulated cores in the three phase colours R/Y/B, the L3 colour (blue) was normally used as neutral in a single-phase application. With a harmonised cable, it makes most sense to me to continue using the L3 colour (grey) as neutral in single-phase work. Then, where old and new cables meet, it doesn't matter whether the application is single or 3-phase, the colours match L1-L1, L2-L2 and L3-L3.

This at least is a reasonable argument for using grey as the neutral replacement when necessary.