SELV garden spike lights

[Steve T]

These holders are 2A rated:

BJB Halogen GU10 Lamp Holder Screw - 25.818.2910.00 | RS

uk.rs-online.com

Subject to max temperature limit, of course!

Generally if you are looking for outdoor rated cable like SWA / tuff sheath / H07RN-F the smallest you usually get is 1.5mm which is about 25 mOhm/m for DC. If you are looking at 3 * 0.7A = 2.1A then 19m until you reach 1V drop.

The "tuff sheath" from Doncaster Cables is easier to use than NYY-J as it is stranded cores, otherwise both are like SWA but without the steel armour and pretty tough. At mains voltages they should not be buried directly in the ground in the UK as our wiring regs require SWA for that role (with its earthed armour) or the use of suitable cable duct for added protection.

H07RN-F is flexible rubber, quite hardy but not suitable for burial in the ground. With some duct or similar it would be a good choice as easy to work with.

These sort of cables can usually be bought by the meter from electrical wholesale outlets or from various web sites like Superlec Direct, CEF, etc.

Thanks for the info, I've just looked at an existing 240v spike lights we have in our garden put in by a sparky some years ago and it seems to come pre flexed with 0.75mm2 H05RN-F, he decided to use 240v as the light was positioned right next to a post so the cable does not need to run on the ground at all. All cable run underground is 1.5mm2 SWA. Presumably any new lights would also come with H05RN-F. So is H05RN-F also suitable for outdoor use? Surely it must be or why would they supply it with that cable?

 

[pc1966]

So is H05RN-F also suitable for outdoor use? Surely it must be or why would they supply it with that cable?

Yes, the '07' and '05' parts of the harmonized code is the voltage limit, but both are fine for the 230V supply range.

You can get less than 1.5mm in most cable types but as that is the smallest for "fixed power wiring" in the UK regs (1mm for lights) it is harder to find it stocked.

 

[Steve T]

I’ve just looked through my records and I’ve fitted around 200 over the past 6 years and no failures. I’ve had to replace 3 drivers in that time. You get a 7 year extended warranty too. Well worth 50 or 60 quid a pop imo.

Fair enough, I'll take a look at them. Wasn't aware of the 7 year warranty!

 

[marcuswareham]

Have a look online, but you can get GU10s and even E27 and B22 in low voltage, I have used them in the past for outside lights and on canal boats.

Most are sold in 12v or 24v, if you go with 24v the current will be slightly less

 

[Steve T]

Have a look online, but you can get GU10s and even E27 and B22 in low voltage, I have used them in the past for outside lights and on canal boats.

Most are sold in 12v or 24v, if you go with 24v the current will be slightly less

Good shout, I'll check that out as well. I've seen stuff like that of questionable quality on ebay in the past but if I can find something from a reputable supplier that might be a good option.

 

[Steve T]

H07RN-F is flexible rubber, quite hardy but not suitable for burial in the ground. With some duct or similar it would be a good choice as easy to work with.

I understand its definitely not OK to bury it by itself especially with 240v going through it but am I right in thinking it would be OK to bury inside some flexible conduit if used for selv applications (ie from the spike light to the junction box) ? I've certainly seen some of the YouTube sparkies do that.

 

[pc1966]

I understand its definitely not OK to bury it by itself especially with 240v going through it but am I right in thinking it would be OK to bury inside some flexible conduit if used for selv applications (ie from the spike light to the junction box) ? I've certainly seen some of the YouTube sparkies do that.

Yes, as well as being RCD protected for 240V use (sicne the cable has no earthed outer layer), that should be proper electrical style duct. This sort of idea:

40mm OD Twinwall Duct x50m; BLACK | Drainfast Ltd

drainfast.co.uk

But for SELV use than anything that provides some mechanical protection will do. More generally with duct you can generally replace failed cable years later without much effort, though ideally you would expect see 25+ years life out of any well-installed system that is not attacked by a JCB, etc.