External lighting and wiring requirements

[Mjward]

Hello

I'm a competent DIY electrician within the home , COVID gave me time to study City & Guilds although my attention was focused on everything within the home.

I've recently replaced my decking and now looking at wiring in the lighting (ip65 240v up/down lights on the decking posts). An electrician hired by the previous owners had simply daisy chained 1.5mm flex/PVC to light fittings but initial searches suggested running SWA to a dedicated junction/wiska box to each fitting THEN running 1.5mm PVC to the light fitting itself.

Two questions if I may:

1) is SWA a requirement when 100% of the route will be above ground
2) what is the maximum permitted distance from the wiska box to the light fitting itself?

Thanks in advance

 

[brianmoooore]

Abandon the 230V lights idea, and go for low voltage stuff.

 

[Mjward]

Abandon the 230V lights idea, and go for low voltage stuff.

I've had unpleasant experiences. Got low voltage LED and drivers internally, but externally was a maintenance issue unfortunately. Have already got the lights, Coastal up/downlights but know that whether it be light fitting or junction box the primary source of failure is water ingress.

Although I've got the SWA and glands, I'm hoping that the requirement is for buried applications and they're a right faff to terminate

 

[westward10]

Use NYY-J much easier.

 

[Mjward]

Use NYY-J much easier.

Is that interchangeable with 3183?

 

[nicebutdim]

It's far removed from 3183.

 

[Mjward]

It's far removed from 3183.

Sorry you're right, its been a long day, actually meant H07RN-F.

I'm against the clock from installation perspective, need it in tomorrow as access gets restricted from Tuesday. Worst case I stick with the SWA I've got on hand, but ideally switch to NYY-J or H07RN-F if I can get hold of on a bank holiday

 

[littlespark]

SWA outside would require weatherproof glands which adds another level of faff to the job.

NYY just needs regular compression glands.

 

[Mjward]

Hit a fairly major snag and I shouldn't be surprised.







Super quick history: previous owners had extension built and almost every aspect has cowboy written all over it. Fitting these lights is a very delayed project. The original outside lights (on this circuit) consisted of a wall light and decking floor lights. The latter were left dangling through the rotten decking and seal had gone, so whenever the light switch was used the FCU would trip.







Recently, I removed the decking floor lights and temporarily terminated their input cable into a junction box (and replaced the decking). From this act, when I flicked the switch the wall light would work and the FCU wouldn't trip. I made the incorrect assumption that it was just an issue with the lights etc.







Fast forward to today, I've just turned the outside lights on, wall light on, but getting nothing from the decking input cable. Thought maybe just pen reader issue, but multimeter confirms the same.







Opened up the junction box next to the working wall light in the hope of some clues, but ignoring the cowboy wiring I should have expected, there was no sign of the white rubber decking cable. To the sole switch that activates this circuit is just standard 1.5mm grey t&e.







So I'm struggling with the logic here. If removing a suspected water ingress light fitting stopped the circuit tripping, then to me that implies that wherever the cowboys buried this hidden junction box connecting this cable from the decking to the switch must still be connected so I don't understand how I'm left holding a dead end

 

[Mjward]

I posted too soon... Think I found the source...and.. wow...

 

[Mjward]

Was part of the issue. Connected it up and nothing. Then opened up the junction box next to the light fitting and although also questionable (earth sleeving seems to be optional) did not fix it.

So moved on to the next item, the wall light, and low and behold there was lonely line terminated into a single choc box waiting to receive some love.

Anyway, a lot of faff latter (used a mix of SWA and H07RN depending on location), we have working lights

Only problem I have now, is that two of the plastic screw head have no thread and don't really know what their proper name is to source replacements. It's to tighten the main light body onto the wall mount threads. Have contacted Toolstation but not hopeful

 

[Avo Mk8]

They are called "dome nuts" and a good old style hardware shop will sell them (metal ones)
Screwfix do sell the larger sizes in quantity! If you can be sure of the M size, you can get them on the internet.

https://www.accu.co.uk/shop/precision-components/nuts/dome-nuts/metric-dome-nuts?Thread+Size=M4+%284mm%29&page=1

 

[Mjward]

They are called "dome nuts" and a good old style hardware shop will sell them.
Screwfix do sell the larger sizes in quantity! If you can be sure of the M size, you can get them on the internet.

Brilliant thank you. Think I'll get an assorted variety as I'm sure I'll come across them again

 

[Avo Mk8]

Brilliant thank you. Think I'll get an assorted variety as I'm sure I'll come across them again

Good idea!

Halfords Dome Nuts (SBOX820) | Halfords UK

Shop the latest The Halfords Dome Nuts (SBOX820) pack contains a variety of common sizes. at Halfords UK

www.halfords.com

 

[mainline]

Hit a fairly major snag and I shouldn't be surprised.







Super quick history: previous owners had extension built and almost every aspect has cowboy written all over it. Fitting these lights is a very delayed project. The original outside lights (on this circuit) consisted of a wall light and decking floor lights. The latter were left dangling through the rotten decking and seal had gone, so whenever the light switch was used the FCU would trip.







Recently, I removed the decking floor lights and temporarily terminated their input cable into a junction box (and replaced the decking). From this act, when I flicked the switch the wall light would work and the FCU wouldn't trip. I made the incorrect assumption that it was just an issue with the lights etc.







Fast forward to today, I've just turned the outside lights on, wall light on, but getting nothing from the decking input cable. Thought maybe just pen reader issue, but multimeter confirms the same.







Opened up the junction box next to the working wall light in the hope of some clues, but ignoring the cowboy wiring I should have expected, there was no sign of the white rubber decking cable. To the sole switch that activates this circuit is just standard 1.5mm grey t&e.







So I'm struggling with the logic here. If removing a suspected water ingress light fitting stopped the circuit tripping, then to me that implies that wherever the cowboys buried this hidden junction box connecting this cable from the decking to the switch must still be connected so I don't understand how I'm left holding a dead end

N to E fault can cause rcd tripping it will do that without having a L feed.

 

[Mjward]

N to E fault can cause rcd tripping it will do that without having a L feed.

On that note, obviously the RCD kept tripping as I was fitting the lights (lesson learnt for next time to have made the connection to circuit last), with the switched of MCB doing nothing to stop the N & E circuits being still connected.

Other than making sure next time I make connecting the lights to the circuit as the LAST job, is there anything else to stop the RCD tripping in that scenario? (I guess other than disconnecting them at the FCU which I am not qualified to do).

I'm very glad my other FCU has RCBO's!

 

[newfutile]

If none of the other circuits on the shared rcd are using power it won't trip, otherwise make sure neutral and earth don't touch at any times

 

[Mjward]

If none of the other circuits on the shared rcd are using power it won't trip, otherwise make sure neutral and earth don't touch at any times

Thank you. Unfortunately it was kitchen stuff, fridge most importantly ie would have wanted to use power. Guess sticking some tape around the exposed N/E to ensure don't touch is the way forward

 

[mainline]

Thank you. Unfortunately it was kitchen stuff, fridge most importantly ie would have wanted to use power. Guess sticking some tape around the exposed N/E to ensure don't touch is the way forward

Most these days would use wagos or similar.

 

[Mjward]

Most these days would use wagos or similar.

Of course, showing my age now!