outdoor lighting cable selection protective device

[Chrishands]

Hi i wanted to clarify what 7671 says about wiring of outdoor lights.
presume the job is a lamp post 0.5M away from the house. Fed from a fused spur unit, with a downrated fuse, inside the house from the upstairs S/O ringmain. The cable would be 1.5mm2 twin earth from the fused unit wall mounted in trunking out through the exterior wall of the property into a PIR sensor. It would then go clipped down the wall until it is just above the dampcourse, into an ip67 Junction box, i would then bring SY 1.5mm 3g out trailing across the block paved drive 30cm into the luminaire.

would i need to RCD protect this cct because the flex is not mechanically protected? is it ok to trail SY cable a few cm into the lamp? as it surely wouldnt be right to hide the cable burried under ground less than 600mm?

any guidance steering me towards regs concerning out door lighting, mechanical protection of cable, rcd requirements of cable. fused spurs would be appreciated. no **** taking as usual, genuined advice would be nice for once.
thanks

 

[davesparks]

SY should not be used outdoors fullstop, check manufacturers spec for it for proof. And look at any bit of SY which has been left outside to see.
Any cable installed outside should be resistant to the effects of sunlight, this effectively limits it to black cables, black conduit, steel conduit or MICC.

Also if you are intent on running a cable on top of a block paved drive then I would suggest that MICC might survive the best but still you should be looking for a better route.

A cable run under bloat paving and suitable protected from damage would be far better than a cable left exposed on the top of the paving.

 

[Octopus]

I would fit an RCD FCU if the RFC isn't RCD protected.

 

[Chrishands]

SY should not be used outdoors fullstop, check manufacturers spec for it for proof. And look at any bit of SY which has been left outside to see.
Any cable installed outside should be resistant to the effects of sunlight, this effectively limits it to black cables, black conduit, steel conduit or MICC.

Also if you are intent on running a cable on top of a block paved drive then I would suggest that MICC might survive the best but still you should be looking for a better route.

A cable run under bloat paving and suitable protected from damage would be far better than a cable left exposed on the top of the paving.

thankyou for your reply, i thought any burried cable MUST be at a min depth of 600MM and protected in conduit on way down and up from surface, is this a myth?

 

[davesparks]

thankyou for your reply, i thought any burried cable MUST be at a min depth of 600MM and protected in conduit on way down and up from surface, is this a myth?

Why do you think that? Can you reference a specific regulation or are you working to myths and mist?

You need to use your common sense, how deep does the cable need to be to protect it from damage by the current or foreseeable use of the ground?

 

[Simlec]

SY should not be used outdoors fullstop, check manufacturers spec for it for proof. And look at any bit of SY which has been left outside to see.
Any cable installed outside should be resistant to the effects of sunlight, this effectively limits it to black cables, black conduit, steel conduit or MICC.

Also if you are intent on running a cable on top of a block paved drive then I would suggest that MICC might survive the best but still you should be looking for a better route.

A cable run under bloat paving and suitable protected from damage would be far better than a cable left exposed on the top of the paving.

"With the right protection (such as keeping it out of direct sunlight), SY Control Cable is useful for outdoor installations. The SY Flex is most suitable, however, for work in dry or moist indoor environments."

SY Control Flexible Cable BS6500, VDE0250

 

[Octopus]

I was faul finding some garden lighting yesterday - installed about 8 years ago - which used SY from an above ground JB to the lights - a quick IR test showed it to be OK!

 

[Chrishands]

Re: outdoor lighting cable selection protective devicek

I was faul finding some garden lighting yesterday - installed about 8 years ago - which used SY from an above ground JB to the lights - a quick IR test showed it to be OK!

Ive seen a lot of compressors and condensers wired in at outdoor, ALOT

 

[Andy78]

thankyou for your reply, i thought any burried cable MUST be at a min depth of 600MM and protected in conduit on way down and up from surface, is this a myth?

522.8.10 for your enlightenment on this matter

 

[Chrishands]

522.8.10 for your enlightenment on this matter

Thanks for that Andy! so if i put an armoured cable (also rcd protected it) surface deep under the block paving drive and you could clearly see it going down into the ground and would obviously be able to assume it goes to the lamppost, would this be 1. sufficient to avoid damage (the block paving would protect it, and what are cable covers (for marking the burried cables)........ could this be acceptable or is this dodgey grounds im treading on. what i mean to say is whats a generally accepted interpretation amongst the electrical community

 

[Octopus]

Thanks for that Andy! so if i put an armoured cable (also rcd protected it) surface deep under the block paving drive and you could clearly see it going down into the ground and would obviously be able to assume it goes to the lamppost, would this be 1. sufficient to avoid damage (the block paving would protect it, and what are cable covers (for marking the burried cables)........ could this be acceptable or is this dodgey grounds im treading on. what i mean to say is whats a generally accepted interpretation amongst the electrical community

Are you planning to sign this off?

 

[davesparks]

"With the right protection (such as keeping it out of direct sunlight), SY Control Cable is useful for outdoor installations. The SY Flex is most suitable, however, for work in dry or moist indoor environments."

SY Control Flexible Cable BS6500, VDE0250

Laying it on the ground as the OP suggests is not giving it the correct protection.

The clear sheath disintegrates in sunlight, water travels up the cable by capillary action.
Green stuff grows under the sheath.
It has very little impact resistance.
The screen is not suitable as a CPC or for conducting fault currents if it is damaged/penetrated.

When compared to other options it just is not suitable for the job.

And to whoever said that they 'have seen it used outside lots of times' DON'T BE A SHEEP! Blindly following the herd without thinking is not good enough.

 

[Simlec]

Dave i'm fully aware of what SY should & should not be used for.
The problem is you said check manufactures spec (people reading thread) and it clearly states it can be used outside along with lots of other wonderfully ways.
It has become as some would say, classed as "armored flex" (which it's not) and adopted by a lot of air con/fridge installs.

 

[davesparks]

What that spec clearly states is that it can only be used outside with additional protection, one example of which is protection from sunlight.
It does not state that it can be used outside on its own.

 

[Simlec]

"Direct sunlight" which shade could provide protection for that. (or get it some sunglasses :coolgleamA

 

[Engineer54]

It's a battle to give good advise on here at times, it really is!!

 

[driverman]

What that spec clearly states is that it can only be used outside with additional protection, one example of which is protection from sunlight.
It does not state that it can be used outside on its own.

What is the BLUE flex used for. Is that designed for outdoor use for all weathers and varying temperatures?

 

[Octopus]

Just use T&E as any bodger would do..... lol

 

[telectrix]

Just use T&E as any bodger would do..... lol

and if really fussy, paint it black.

 

[Octopus]

and if really fussy, paint it black.

hum... green as its in the garden!

 

[davesparks]

What is the BLUE flex used for. Is that designed for outdoor use for all weathers and varying temperatures?

It depends on the type of insulation and sheath it has.
There is blue PVC flex, blue HO5 flex and blue arctic flex on the market.
All three are being sold as 'arctic grade' but only one of them can actually stand up to external use.

Years ago it was acceptable to use blue arctic in the events industry, but it has not been allowed for a few years now due to there being so much blue flex around which is not suitable for outdoor use.

And if you do get proper arctic flex then you will find that, as the name suggests, it's main feature is flexibility at very low temperatures. It does not have the good mechanical strength of HO7-RNF which is the current standard.

 

[shanky887614]

It depends on the type of insulation and sheath it has.
There is blue PVC flex, blue HO5 flex and blue arctic flex on the market.
All three are being sold as 'arctic grade' but only one of them can actually stand up to external use.

Years ago it was acceptable to use blue arctic in the events industry, but it has not been allowed for a few years now due to there being so much blue flex around which is not suitable for outdoor use.

And if you do get proper arctic flex then you will find that, as the name suggests, it's main feature is flexibility at very low temperatures. It does not have the good mechanical strength of HO7-RNF which is the current standard.

there is also blue armoured.

i think it looks nicer than black swa lol, pretty colours lol

 

[davesparks]

Yes, I think that will be LSF/LSZH or to denote that it made to another specific standard.

But he did specifically ask about blue flex.