swa garden lights

I'm newly qualified and I'm going to install some garden lights for a client.  I asked another NICEIC electrician with some years behing him regarding the best way to go about it and he recommended terminating 4core swa cable straight into nylon stuffing glands and then just twisting and terminating the armour together into a terminal, whilst using one of the cores as the earthing conductor.  This sound pretty dodge to me! But is this what a lot of people do?  It would save a hell of a lot of time not terminating 30+ swa terminating glands.

thank you v much

Why 4-core to work a light? 

Doc H.

Seriously?....I think you need to ignore any other advice that he gives you

Sounds like a real bodge by your description ...

30+ lights , how long is the cable run? Done any calcs yet?

SWA cable  made off without waterproof  glands  .....by an NICEIC sparks   eh!       Twist the armouring together in a terminal  ...do the job properly FFS!  

Bet he doesn't put that job on the list for annual inspection .     

What IS the reason for the  4 core ?    

Doc Hudson said:

Why 4-core to work a light? 

Doc H.

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Yeah I just meant 3 core actually, and a 4 core from the light switch.

Murdoch said:

Sounds like a real bodge by your description ...

30+ lights , how long is the cable run? Done any calcs yet?

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16 lights, but it's going to be 2 armoured glands per a junction box and then one stuffing gland.  The client hasn't picked the exact lights yet so no I haven't,  I was assuming a 6amp breaker was going to suffice,  may I be assuming incorrectly?  As for voltage drop. the garden's fairly small so I assumed that would be ok as well lol,  maybe I should check that through haha

Evans Electric said:

SWA cable  made off without waterproof  glands  .....by an NICEIC sparks   eh!       Twist the armouring together in a terminal  ...do the job properly FFS!  

Bet he doesn't put that job on the list for annual inspection .     

What IS the reason for the  4 core ?    

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I mean the stuffing glands would be water proof, and he reccommended using magic gel (which I would have anyways), so I can't actually think what is that bad about the idea apart from than in a spade through the cable situation the armour would be poorly earthed. 

Thank you very much for the replies.  I'm a heating engineer by trade, and mainly got the electrical qualification so I can install air con units, so am a bit of a newbie really. 

Murdoch said:

Sounds like a real bodge by your description ...

30+ lights , how long is the cable run? Done any calcs yet?

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Now that I think about it, 1 junction box per a light seems overkill, I just wanted as little flex as possible to the light, what's good practise?  It' going to be really expensive otherwise

Most of these garden lighting jobs have an SWA  looping  in a daisy chain .

Fit a waterproof box as near to the fitting as possible .   

Make off SWA,s using the correct glands .

Then most garden lights have a flex attached   ,  All you can do is connect the flex to the box using waterproof gland .   Keep the flexes as short as possible .   Forget this lettuced about not using glands . 

Its as expensive as it has to be  because it has to done correctly ,   if he's not happy , get the masked NICEIC man  to  mosey on up on the next stagecoach  to do it . 

Evans Electric said:

Most of these garden lighting jobs have an SWA  looping  in a daisy chain .

Fit a waterproof box as near to the fitting as possible .   

Make off SWA,s using the correct glands .

Then most garden lights have a flex attached   ,  All you can do is connect the flex to the box using waterproof gland .   Keep the flexes as short as possible .   Forget this lettuced about not using glands . 

Its as expensive as it has to be  because it has to done correctly ,   if he's not happy , get the masked NICEIC man  to  mosey on up on the next stagecoach  to do it . 

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Point taken.

I've decided to basically only use 5 junction boxes with swa cables and glands to each group of closely located lights and then just use black plastic sleeving for the black flex, so there will be about 0.5m of buried flex in black conduit to some of the light fittings, am going to put yellow tape around the plastic conduit.  Does this sound reasonable in your opinion?

Thank you very much for the reply much appreciated 

Sounding better .  Use black PVC rigid conduit  . its tough as old boots. 

Evans Electric said:

Sounding better .  Use black PVC rigid conduit  . its tough as old boots. 

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I've now also read "PVC breaks down over time especially with exposure to UV ray and is responsible for the many poor installations we hear about due to capillary action where moisture gets into the connections and leads to the fittings breaking down and short circuits blowing the LED chips and often tripping the RCD unit".

This website is saying to use  HO7RN-F 3-core rubber cable (rubber butyl) to the actual light fittings, does this sound worth doing?.  Do many of the light fittings come ready installed with PVC flex cable and therefore would would need to be un installed for the rubber cable instead?

thanks again

^^ who is deciding on the fittings? 

I’ve ripped out a load of garden lights where the “alleged” hno5 / 7 had deteriorated in just over 1 year and was the cause of the RCD tripping.

i contacted the manufacturer who stated that more than 1 year was acceptable life - the cable they used was Far East import. 

Murdoch said:

contacted the manufacturer who stated that more than 1 year was acceptable life - the cable they used was Far East import. 

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Don't that just sum up some of the carp we get these days. ?

jumpjamesjump said:

I've now also read "PVC breaks down over time especially with exposure to UV ray"

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That applies to cables but not conduit (although black conduit will be bleached by the UV rays and go a greyish colour on the top half).

The breakdown of PVC occurs due to the effect on the plastisicer and turns it brittle (the sheath on twin and earth goes almost white and starts to crack outside), things like window frames and trunking are made from Upvc, with the U being unplasticised, i.e. it is a ridgid plastic and is not flexable like a cable, and while there might be a bit of embrittlement over the years, it doesn't suffer the same fate as oridnary PVC.

Some PVC can have UV stablisiing compounds added to the mix, which you get for thinks like the PVC oversheath on SWA, I learned once that tye wrapps are availble with and without it, but no one really worries about that too much, unless they break after twenty years and the SWA to a ticket office falls off the tray above the raileay, hangs down, and then is caught by the train and is pulled out the glands and whips back, causing damage/injuries

Phoenix said:

ticket office falls off the tray above the raileay, hangs down, and then is caught by the train and is pulled out the glands and whips back, causing damage/injuries

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Which would never happen

 Always thought black ones were UV stabilised ........another school day!

kerching said:

Which would never happen

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I think it nearly did recently...

kerching said:

Which would never happen

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https://assets.publishing.service.gov.uk/media/5af17460ed915d5869f418df/R062018_180509_Abergavenny.pdf

Oooh that's not good! I wasn't aware of this. (Link didn't work so I had to Google it)

that could have caused a lot more injuries

That comes across as a thorough and well written investigation report.

Geoff1946 said:

That comes across as a thorough and well written investigation report.

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they usually are. done to find out what happened and what can be changed to prevent it happening again rather than pointing the blame