3 core and earth H05RN-F flex for outdoor lights.

2 Dec 2014
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United Kingdom
I'm after some 3 core and earth outdoor type(H05RN-F?) flex to replace a section on my outdoor lights.

The exisiting flex is probably not outdoor type stuff as the sheath is perished and failing.

The flex goes between a junction box and a PIR.

The existing flex is 3 core with the green and yellow earth core used as the switched live.

The only outdoor cable I can find to replace it with is 3 core pond flex, but then I would have to sleeve the earth colours to signify switched live, which doesn't feel right?

It also doesn't seem right to leave the earth out as my understanding is that it is there to protect the whole circuit(even the wire), even if the end appliance is double insulated?

The junction box is supplied with 3 core and earth, it looks like hi-tuff. I can see why the original installer added the junction box and flex because there isn't any way that the hi tuff is going to fit or bend into the PIR terminal block!
I tried that already and it is impossible!

So does anyone know where I can get 3 core and earth outdoor(pond) type cable?

Or do you think it would be OK to just replace with the pond flex with the earth colour sleeved and the earth omitted for the short 15cm inaccessible(without a ladder) run of flex?

FYI, the PIR supplies 2 linked 30Watt LED type outdoor lights(these must have been updated more recently than the PIR flex), which is why there is a switched live.

The PIR is double insulated and high up out of reach at the eves.

Any ideas for a replacement solution?
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Four core TRS is the way to go. We use .75, 1.0, 1.5 & 2.5mm2 in 3 core, 4 core & 5 core at work so its made. However buy a couple of metres might be an issue..... try a more 'industrial' wholesaler .... or a popular online auction site?

Over-sleeving the Gn/Ye isn't really the 'proper' thing to do
Thanks Adrian, I've just been googling TRS and it seems most of the TRS flexes can be used outdoor, but not permanently.

H05RR/ RN-F is not for permanent use.

I'm just looking for a reference to H07RN-F suitability for permanent outdoor use as there is some 4 core of that on ebay! I hope the 1.5mm will fit in the PIR!

This is heck of a lot of faff for a simpe job and every google result contains stories of electricians using the wrong type of cable!

I was getting nowhere before your TRS reference. I did just think of using 2 length of pond flex to the PIR. I can't see any problem with this? Can anyone else?

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